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R E P O R T
DRAFT
SDMS DocID 2009041
Feasibility Study Report
Former Koppers Company, Inc.Newport SiteNewport, Delaware
Beazer East, Inc.Pittsburgh, Pennsylvania
E. I. du Pont de Nemours and CompanyWilmington, Delaware
September 1999
BBL_ BLAS.AND BOUCK & LEE, INC
e '~ g , n e e ' s & s c > e ' ' • s ' s
A R 3 I U I 0 7
JUN-18-1999 17=39 BLflSLflND.BOUCK & LEE 315 449 0017 p.02/07
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Former Koppers Company, Inc. Newport SiteNewport, Delaware
Proposed Feasibility Study Outline
Executive Summary
Section 1 - Introduction
1.1 Purpose and Scope
1.2. Site Description
1.3 Summary of Rl
- physical characterization
- ecological characterization
- constituent nature and extent
- constituent fate and transport
1.4 Overview of Rl/FS Risk Management Framework
1.5 Summary of Baseline Risk Assessments
1.5.1 Human Health Risk Assessment
1.5.2 Ecological Risk Assessment ^~ jrxa-kv.^ tpA'j
Section 2 - Remedial Action Objectives and General Response Actions
2.1 Overview
2.2 Identification and Rationale for ARARs
2.3 Remedial Action Objectives
2.4 Areas Potentially Subject to Remediation
2.5 General Response Actions
Sediment
1. No Action
2. Natural Processes
3. Institutional Control
4. Hydraulic Modification (Rechannelization/Relocation)
5. In-place Containment
6. Removal of Selected Areas with On- or Off-Site Disposal
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AR3U
JUN-18-1999 17=40 BLPSLftND,BOUCK a LEE 315 449 0017 P.03/07
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Soil
1. No Action
2. Natural Processes
3. Institutional Controls
4. In-Place Containment
5. Removal of Selected Areas with On- or Off-Site Disposal ^v''
PGround Water *
^1. No Action ^
2. Natural Processes/Monitoring
3. Institutional Controls
4. Enhanced natural attenuation (i.e., nutrient addition)
5. Ex-situ Treatment (Pump and Treat)
NAPL
1. Technical Impracticability Waiver for Subsurface Soils
2. Removal of Free Product (proposed for wells MW-2A and MW-8A)
Section 3 - Development and Screening of Remedial Alternative Components
3.1 General
3.2 Identification and Screening of Remedial Technologies and Process Options
Tables:
Sediment Technologies
Soil Technologies
Groundwater Technologies
NAPL Technologies
3.3 Evaluation of Process Options and Assembly of Remedial Alternative Components
3.3.1 Evaluation Criteria (description of effectiveness, implementability, cost)
3.3.2 Selection of Representative Process Options
3.3.3 Remedial Alternatives Assembled for Further Analysis
Surface Soil
1. No Action
Required by CERCLA as a baseline for comparative analysis.
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JUN-18-1999 17=40 BLASLPND,BOUCK & LEE 315 449 0017 P.04/07
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2. In-Situ Containment
Placement of an engineered cover over areas where surficial
creosote deposits are present.
3. Removal of Selected Areas with On- and/or Off-Site Disposal
Mechanical excavation of surficial creosote deposits with On-
and/or Off-site disposal.
Sediment
1. No Action
Required by CERCLA as a baseline for comparative analysis.
2. Natural Recovery
Natural covering of sediment due to ongoing deposal of
cleaner sediment (natural degradation processes)
3. Engineered Containment
Placement of an engineered cover over sediment
4. Hydraulic Modification
Relocate Hershey Run
5. Removal of Selected Areas with On- and/or Off-Site Disposal.
Mechanical removal of sediment with appropriate disposal.
Subsurface Soil
1. No Action
Required by CERCLA as a baseline for comparative analysis.
2. Natural Attenuation with Monitoring
. Monitor to confirm NAPL is not migrating.
3. Technical Impracticability Waiver
Site conditions related to subsurface NAPL makes it
technically impractical to actively remediate.
Groundwater
1. No Action
Required by CERCLA as a baseline for comparative analysis.
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JUN-18-1999 17=40 BLPSLPND,BOUCK & LEE 315 449 0017 P.05/07
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2. Natural Attenuation with Monitoring
Ongoing natural processes reduce the concentration of site-
constituents that may potentially migrate off-site.
3. Enhanced Natural Attenuation
Addition of nutrients to enhance natural biological
degradation processes.
NAPL
1. Technical Impracticability Waiver
2. Removal of free product (proposed for wells MW-2A and MW-8A)
Section 4 • Detailed Evaluation of Remedial Alternatives
4.1 General
4.2 Evaluation Criteria (description of nine NCP criteria)
4.3 Alternative 1 - No Action
4.4 Alternative 2 - Monitoring with Institutional Controls
4.5 Alternative 3 -
Natural encapsulation (sediment - Hershey Run)
• Surface soil excavation with on-site disposal (surficial creosote areas)
• Capping (Fire Pond, South Pond, K Area)
Natural Attenuation (groundwater)
Technical Impracticability Waiver (Subsurface NAPL); monitoring and free-
NAPL recovery.
4.6 Alternative 4 -
Hot-Spot removal with on-site disposal (sediment - Hershey Run)
Surface soil excavation with on-site disposal (surficial creosote areas)
• Excavation with on-site disposal (Ptre Pond, South Pond, K Area)
• Natural Attenuation (groundwater)
Technical Impracticability Waiver (subsurface NAPL); monitoring and free-
NAPL recovery.
4.7 Alternative 5 -
Rechannelization/relocation (sediment - Hershey Run)
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JUN-18-1999 17=40 BLPSLftND.BOUCK 8. LEE 315 449 2017 P.06/07
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• Removal, on-site disposal, cover residuals and facilitate drainage flow (Fire
Pond, South Ponds, K Area)
• Removal, on-site disposal of surface soil (surficial creosote areas)
• Natural Attenuation (groundwater)
• Technical Impracticability Waiver (subsurface NAPL); monitoring and free-
NAPL recovery
4.8 Alternative 6 -
• Dredge, treat and off-site disposal (sediment - Hershey Run)
• Remove and off-site treatment of surface soil (surficial creosote areas)
• Sediment excavation with off-site treatment (Fire Pond, South Pond, K Area)
• Enhanced Natural Attenuation (groundwater)
• Technical Impracticability Waiver (subsurface NAPL); monitoring and free-
NAPL recovery
Section 5 - Comparative Analysis of Alternatives
5.1 General
5.2 Criteria Assessment
Section 6 - Summary of Recommended Remedial Alternative
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A R 3 I U I 12
Work Activity
1. Meeting with Agencies
2 Submit Draft FS Outline to Agencies for Review
3. Agencies Review Draft FS Outline _ _
4 Receive Agencies' Comments on Draft FS Outline-
S DeveloD Draft FS -. - ..- -^
6. Submit Draft FS to Agencies for Review
8 Develop Tl Waiver
9 Agencies Review Draft FS
1999
May
. _ JL
June
r~n
A
July
- A .-!Tj""vr j
August
s
September Oclober November
LEGEND:
l"-*vi Action Item Duration
A Milestone/Submfttal
FS Feasibility Study
SOW Statement of Work
Tl Technical Impracticability
so
A
srr >
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8YR4M4-DJH3e7l7l«Q087IIiOI.CO<<
FORMER KOPPERS COMPANY. INC. NEWPORT SITENEWPORT. DELAWARE
PROJECT SCHEDULE
BBL BIASUWR BOUCK & IEE. INC.FIGURE
1
BLASLAND, BOUCK ft LEE. MC.
Transmittal
Transmitted Via: Federal Express
To: Matthew MellonUSEPA Region IIIM/C 3H5231650 Arch StreetPhiladelphia, PA 19103-2029
We are sending you x herewith
. drawings
BLASLAND, BOUCK & LEE, INC.6723 Towpath Road/Box 66 Syracuse, New York 13214-0066(315)446-9120
Date: November 5, 1999
File: 387.17
Re: Koppers/Newport Site
under separate cover
letters other
If material received is not as listed, please notify us at once.
Quantity
3
Identifying Number Title
Draft-Feasibility Study ReportFormer Koppers Company, Inc.Newport SiteNewport, Delaware
Action*
1
*Action letter code: R - reviewed N - reviewed and noted 1 - for your information A - for your reviewS - resubmit J - rejected Y - for your approval and comment
Remarks:
As you requested.
Sincerely,
BLASLAND, BOUCK & LEE, INC.
David W. Hale, P.E.Vice President
/lar
UALAR99VTRANSMmMELLON WPDA R 3 I U I 1
BBLBLASLAND, BOUCK & LEE, INCe n g i n e e r s 81 sciantists
Transmitted Via Federal Express
September 30, 1999
Matthew MellonUSEPA Region III1650 Arch StreetPhiladelphia, PA 19103-2029
Re: Draft Feasibility Study - Former Koppers Co., Inc. Newport SiteProject* 387.17.100
Dear Matthew:
On behalf of Beazer East, Inc. and E.I. du Pont de Nemours and Company, Inc., Blasland, Bouck & Lee, Inc.is pleased to provide for your review and comment this Draft Feasibility Study for the Former Koppers Co.,Inc. Newport Site, Newport, Delaware.
Should you have any questions, please do not hesitate to contact either Jane Patarcity, Maryann Nicholsonor me.
Very truly yours,
BLASLAND, BOUCK & LEE, INC.
David W. Hale, P.E.Vice President
Attachment
DWH/jllU:\TLA99\68791680WPD
cc: Jennifer Hubbard, EPABernice Pasquini, EPAJeff Turtle, EPAMark Sprenger, EPAMarjorie Zhang, DNRECJohn Brzezenski, USACE/TetraTech NUSJane Patarcity, Beazer, Inc.Maryann Nicholson, DuPontLucinda Jacobs, Exponent
6723 Towpath Road • P.O. Box 66 • Syracuse, NY 13214-0066Tel (315) 446-9120 • Fax (315) 449-0017 • www.bbl-inc.com
Offices Nationwide R D *J I I I
DRAFT
JBBLBLASLAND, BOUCK & LEE, INC.
Feasibility Study Report
Former Koppers Company, Inc.Newport SiteNewport, Delaware
Beazer East, Inc.Pittsburgh, Pennsylvania
E. I. du Pont de Nemours and CompanyWilmington, Delaware
September 1999
engineers & scientists
6723 Towpath Road, P.O. Box 66Syracuse, New York, 13214-0066(315)446-9120
A R 3 I M 1 6
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Table of Contents
Section 1.
Section 2.
Introduction 1-11.1 Purpose and Scope 1-11.2 Site Description and Operational History 1-21.3 Summary of Remedial Investigation 1-31.3.1 Physical Characterization 1-51.3.1.1 Geology 1-51.3.1.2 Hydrogeology 1-71.3.1.3 Sediment and Surface Water 1-81.3.2 Ecological Characterization 1-91.3.2.1 Terrestrial Habitats 1-91.3.2.2 Aquatic/Wetland Habitats 1-101.3.2.3 Threatened/Endangered Species 1-111.3.3 Constituent Nature and Extent 1-111.3.3.1 NAPL Observations 1-121.3.3.2 Analytical Results 1-131.3.4 Constituent Fate and Transport 1-161.3.4.1 Soils 1-161.3.4.2 Sediment/Surface Water 1-171.3.4.3 Groundwater 1-171.3.5 Summary of Cultural Resources Surveys 1-181.4 Summary of Baseline Risk Assessments 1-191.4.1 Human Health Risk Assessment 1-191.4.2 Ecological Risk Assessment 1-201.4.2.1 Overview of the Risk Assessment Approach 1-211.4.2.2 Evaluation of Assessment Endpoints 1-231.4.2.3 Ecotoxicity Thresholds 1-25
Development of Remedial Action Objectives and General ResponseActions 2-12.1 Overview 2-12.2 Identification and Rationale for ARARs and ARAR
Waivers 2-12.3 Remedial Action Objectives 2-32.4 Areas Potentially Subject to Remediation 2-52.4.1 Upland Area 2-62.4.2 Drainage (marsh) Areas 2-62.4.3 Hershey Run 2-72.4.4 Fire Pond 2-82.4.5 South Ponds 2-82.4.6 KArea 2-82.4.7 Summary of Areas and Volumes 2-92.5 General Response Actions 2-9
BLASLAND, BOUCK & LEE, INC.57391832 .WPO-9/30/99 engineers & scientists
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Section 3.
Section 4.
Development and Screening of Remedial AlternativeComponents 3-13.1 Overview 3-13.2 Identification of Remedial Technologies and
Process Options 3-13.3 Screening of Remedial Technologies and Process
Options 3-23.3.1 Sediment Technologies 3-23.3.1.1 No Action 3-23.3.1.2 Monitoring with Institutional Controls 3-33.3.1.3 In-Place Containment 3-43.3.1.4 Ex-Situ Treatment 3-63.3.2 Soil Technologies 3-93.3.2.1 No Action 3-93.3.2.2 Monitoring with Institutional Controls 3-103.3.2.3 In-Situ Containment 3-113.3.2.4 Ex-Situ Treatment 3-133.3.3 Groundwater Technologies 3-143.3.3.1 Current Conditions and Appropriateness of a Tl
Determination 3-143.3.3.2 Tl Zone and Alternative Remedial Strategy 3-163.3.3.3 No Action 3-213.3.3.4 Monitored Natural Attenuation 3-223.3.3.5 Groundwater Recovery and Treatment 3-233.4 Assembly of Potential Remedial Alternatives 3-24
Detailed Evaluation of Remedial Alternatives 4-14.1 Overview 4-14.2 CERCLA Evaluation Criteria 4-14.3 Alternative 1 - No Action 4-34.4 Alternative 2 - Monitored Natural Attenuation,
Institutional Controls, and Pilot Study 4-54.5 Alternative 3 - Upland surface soil removal, upland
sediment containment, on-site disposal, monitorednatural attenuation, institutional controls, and pilotstudy 4-9
4.6 Alternative 4 - Hershey Run rechannelization,upland surface soil and sediment removal, on-sitedisposal, monitored natural attenuation,institutional controls, and pilot study 4-13
4.7 Alternative 5 - Hershey Run sediment removal,upland surface soil and sediment removal, off-sitethermal treatment, groundwater recovery andtreatment, monitoring, institutional controls andpilot study 4-17
BLASLAND. BOUCK & LEE. INC.57391832.WPO- 9/3CW9 engineers & scientists
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Section 5.
Section 6.
Comparative Evaluation of Remedial Alternatives 5-15.1 Overall Protection of Human Health and the
Environment 5-15.2 Compliance with ARARs 5-15.3 Long-Term Effectiveness and Permanence 5-25.4 Reduction of Toxicity, Mobility, or Volume Through
Treatment 5-25.5 Short-Term Effectiveness 5-25.6 Implementability 5-35.7 Cost 5-35.8 Identification of Recommended Alternative 5-4
References 6-1
Tables 1-1 Weight-of-Evidence Approach and Ranking of MeasurementEndpoints for the Ecological Risk Assessment
2-1 Summary of Federal and State ARARs and TBCs
2-2 Ecological and Cultural Characteristics of Areas Potentially Subjectto Remediation
3-1A Preliminary Screening of Potentially Applicable SedimentRemedial Technologies
3-1B Preliminary Screening of Potential Soil Remedial Technologies
3-1C Preliminary Screening of Potential Groundwater RemedialTechnologies
4-1 Potential Impacts of Remedial Alternative 1
4-2 Potential Impacts of Remedial Alternative 2
4-3 Potential Impacts of Remedial Alternative 3
4-4 Potential Impacts of Remedial Alternative 4
4-5 Potential Impacts of Remedial Alternative 5
4-6 Alternative 1 - Preliminary Cost Estimate
4-7 Alternative 2 - Preliminary Cost Estimate
4-8 Alternative 3 - Preliminary Cost Estimate
BLASLAND, BOUCK & LEE, INC.57391832.WPO-9/30/99 engineers & scientists
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4-9 Alternative 4 - Preliminary Cost Estimate
4-1OA Alternative 5 - Preliminary Cost Estimate for Thermal Desorption
4-1 OB Alternative 5 - Preliminary Cost Estimate for Incineration
Figures
Appendix
1-1 Site Location Map
1-2 Site Plan
1-3 Surficial Creosite NAPL Deposits Delineation
1 -4 Extent of NAPL Below the Water Table
1-5 NAPL Delineation in Sediment
1-6 Evaluation of Assessment Endpoints
2-1 Remedial Action Objectives from Risk Assessment
2-2 Surficial Creosote Areas and Soil and Sediment SamplingLocations with TPAH Concentrations Greater ThanEcotoxicological Threshold
Appendix A - Preliminary Natural Attenuation Assessment
BLASLAND. BOUCK & LEE. INC.5739I832.WPD- 9/30/99 engineers & scientists
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1. Introduction
1.1 Purpose and Scope
This Feasibility Study (FS) report presents an evaluation of several remedial action alternatives developed for the
former Koppers Company, Inc., Site in Newport, Delaware. The report details how five different remedial
alternatives, including numerous specific subcomponents, were developed and evaluated to select an overall remedy
that would be protective of human health and the environment, implementable with minimal adverse impacts to
the ecosystem and surrounding community, and cost-effective in reducing potential risks at the Site.
This introductory Section 1 continues with a description of the Site and a summary of results and conclusions
presented in the Remedial Investigation (RI) report prepared by Blasland, Bouck & Lee, Inc. (BBL, 1999), the
Human Health Risk Assessment (HHRA) prepared by Environmental Standards, Inc. (1997), and the Ecological
Risk Assessment (ERA) prepared by the U.S. Environmental Protection Agency (USEPA, 1997a). Several other
technical documents were relied upon to prepare this FS and are referenced as appropriate. Section 2 discusses the
various applicable or relevant and appropriate requirements (ARARs) that a final remedy must meet, and identifies
the remedial action objectives (RAOs) and general response actions (GRAs) for the Site. Section 3 summarizes
the initial screening of remedial technologies and process options based on technical feasibility, implementability,
and cost, followed by a description of the five potential remedial alternatives assembled for detailed evaluation.
Sections 4 and 5, respectively, present a detailed evaluation and comparative analysis of the alternatives, that justify
the recommended remedial alternative summarized in Section 6.
This document was prepared by BBL, with assistance from Exponent, Inc., on behalf of Beazer East, Inc. (Beazer)
and E. I. du Pont de Nemours and Company (DuPont). Pursuant to an Administrative Order on Consent for the Site
effective October 4,1991 (USEPA, 1991), this document was prepared in accordance with the requirements of the
Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended, the
National Oil and Hazardous Substances Pollution Contingency Plan (NCP), and other applicable federal guidance
and directives including Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA
(USEPA, 1988).
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1.2 Site Description and Operational History
The Site is located in the northern part of New Castle County in Delaware, southwest of the Town of Newport and
northwest of the Route 1-95 and Route 141 interchange (Figure 1-1). To the north, the Site is bordered by high-speed
railroad lines. Beyond the rail lines are a municipal sewage disposal facility, industrial property, and a residential area
(^ Sij3h«rfiortlv To the east, the Site is bordered by the DuPont Holly Run Plant and the Christina River. To the south
attdTvest, the Site is bordered by White Clay Creek and Hershey Run, respectively.
The Site is approximater^SoO acresirvsize. Undeveloped portions of the Site are naturally vegetated with early
successional old field, deciduous woodland, and wetland cover types. Approximately 160 acres are upland areas,
and approximately 140 acres are tidal and non-tidal wetlands. Grasses and shrubby vegetation dominate the northern
half of the Site. The majority of the southern half consists of tidal wetlands, but forested areas occur in the southern
uplands and along the upland/wetland boundaries. Non-tidal wetlands include isolated shallow depressions with
emergent vegetation, wetland shrub and forest areas nearer to the tidal wetlands, and man-made ponds. Three man-
made ponds are located within the Site: the Fire Pond in the northwest corner of the uplands and two ponds in the
southern-central portion in an area called the South Ponds Area (Figure 1-2).
Land use contiguous with the Site is industrial or undeveloped marshes, wetlands, and waterways. No residentialJjtCi-fl-i^ V- '-<-*>••'' T\~< \:^-Cii^> (
properties border the Site, and no drinking water wells are located within the Site boundaries. Access to the Site is
restricted through the use of fencing, posting, and 24-hour security-guarded gates. In addition, natural barriers such
as the Christina River, White Clay Creek, Hershey Run, and the surrounding marshes and wetlands limit access to
the Site, as does the high-speed Amtrak rail line to the north.
Existing facilities/structures and other physical features at the Site include one warehouse building (constructed by
the New Castle County Department of Public Works), a paved access road, and secondary roads providing access
to overhead power lines that traverse the Site. With the exception of some remaining railroad ties, the railroad siding
lines once present at the Site no longer exist.
Located in the northwestern portion of the Site, the Process Area was utilized for the application of wood
preservatives, and contained various wood-treatment equipment and associated structures. This area also had a
loading dock and provided for storage of creosote and other process-related materials. After treatment, the freshly
treated wood products were temporarily allowed to cure in the Drip Track Area prior to transfer to the Wood Storage
BLASLAND, BOUCK & LEE, INC.F:\USERaLW,UKR99\5739l832.WPD - 9/30/99 engineers & scientists 1-2
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Area. The Fire Pond Area was built as a source of water for fire-fighting purposes. Covering the southern two-thirds
of the former operations area, the Wood Storage Area provided temporary storage of creosote-treated and untreated
wood before being shipped from the Site. The railroad tracks within this area were used for storage of finished and
unfinished wood products.
For purposes of Site investigation, these areas, the Process Area, Loading Dock, Drip Track Area, Wood Storage
Area, and Fire Pond Area, are collectively part of the approximately 163-acre "Upland Area" of the Site, which also
includes the South Ponds Area, K Area, and the "Remaining Uplands" (refer to Figure 1-2). Wetland marsh and
drainageways surround the Upland Area on three sides, cover approximately 136 acres, and include the lower reach
of the Hershey Run channel, the Hershey Run Drainage Area, the West Central Drainage Area, the East Central
Drainage Area, the Central Drainage Area, and the East Drainage Area (Figure 1-2). These various area designations
are primarily intended as convenient labels and approximate areal boundaries for describing different sampling areas,
but also correlate with known physical/hydrologic features and past industrial uses.
Additional background information is presented in the RI report (BBL, 1999), including a summary review of nearly
20 historical aerial photographs spanning the 52 years between 1937 and 1989.
1.3 Summary of Remedial Investigation
An extensive on-site field investigation was conducted in three primary phases between 1994 and 1997. This
investigation involved the collection and analysis of over 1700 samples of groundwater, surface water, soils,
sediments, air, and biota. Data collection efforts also included extensive observations of the physical and ecological
features of the Site to characterize the diverse geologic, biologic, and wetland resources at the Site. These efforts
were organized into a series of concurrent, but distinct, investigations that are described in detail in the RI report
(BBL, 1999).
This section of the FS summarizes the findings detailed in the RI report, including an overview of the scope of the
investigations. Also summarized here are the physical and ecological characteristics of the Site, and the nature and
extent, and fate and transport, of constituents of potential interest at the Site.
Soil Investigation - More than 700 soil samples were collected from over 500 locations across the Site. Historical
deposits of non-aqueous-phase liquid (NAPL) material (typical of former wood-treating operations at the Site) were
BLASLAND. BOUCK & LEE. INC.engineers & scientistsF:\USEF3\mLAR99\5739l832.WPD - 9/30/99
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/observed in surface soils at several locations across the Site. NAPL was also observed in certain subsurface soils;
however, the RI report (BBL, 1999) describes how the natural geologic conditions (e.g., a continuous subsurface
layer of low-permeability clay) and physical form and location of the NAPL combine to limit the areal extent and
mobility of the NAPL materials.
Sediment Investigation - The western, southern, and eastern perimeter of the Site is dominated by wetland and
riverine environments. Three ponds are also present on the upland portion of the Site. Nearly 500 sediment
samples were collected from these areas and several off-site reference areas to characterize the nature and extent
of NAPL and other constituents. Concentrations of metals, polychlorinated biphenyls (PCBs), pesticides, and
dioxin/furan compounds are low in upland areas of the Site and highest in off-site locations and the surrounding
marsh areas.
Hydrogeologic Investigation - A total of 24 monitoring wells were installed to characterize groundwater
conditions (an additional 22 nearby residential and commercial water-supply wells also were sampled).
Approximately 300 groundwater samples were collected in 5 sampling events, and analyzed for the presence of
polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), semivolatile organic compounds
(SVOCs), pesticides, PCBs, metals, and dioxin/furans. Among other results, the RI report describes how naturally
occurring attenuation mechanisms are mitigating the movement of constituents from potential source areas.
Surface Water Investigation - Approximately 180 samples of surface water were collected under a variety of
hydrologic conditions from nearly 50 on- and off-site locations to characterize local and regional water quality.
Under both base-flow and storm-flow conditions, VOCs, SVOCs, pesticides, PCBs, and dioxin/furans were
typically not detected, with few exceptions. Metals were detected in most samples, with the higher
concentrations typically detected in unfiltered samples, suggesting that the metals are associated with the
paniculate phase of the water sample.
Ecological Investigation - On-site observations and analytical measurements were made to characterize the
diverse variety of plant and animal communities observed at the Site and to provide data necessary for
completion of human and the ecological risk assessments for the Site. Included in these efforts was a
comprehensive delineation of jurisdictional wetlands, extensive on- and off-site vegetative and wildlife surveys,
BLASLAND. BOUCK & LEE. INC.F:\uSERS«.FM_AR99\57391832.WPD--9/30fl9 engineers & scientists
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and surveys of macroinvertebrate and fish populations. A number of ecotoxicological tests were also performed
for use in the ERA.
Air Investigation - Ambient air quality was measured at 32 sampling locations across the Site, and results were
found to be consistent with background conditions. •> -)X^" ' ^" J • "3 ^ ^r p r *c/~-- ^of ' -s.^V^ -^ ^
• Other Investigations - A number of other field efforts were undertaken to identify the potential presence of
underground piping and storage tanks. In addition, Phase IA and IB Cultural Resources Surveys were conducted
to identify locations of potential archeological significance.
1.3.1 Physical Characterization
The physical setting of the Site and surrounding region is fully described in the RI report (BBL, 1999). For
purposes of this FS, the prominent geologic and hydrogeologic features are briefly summarized below.
1.3.1.1 Geology
There are four primary overburden geologic units of interest at the Site: fill, other Quaternary deposits, the Columbia
Formation, and the Potomac Formation.
Fill - Fill is the uppermost unit encountered in the uplands area, and varies in thickness from 0 to approximately 9
feet with greater thicknesses observed in the Process and Fire Pond Areas. The fill is comprised of primarily silts
with lesser amounts of sands, gravels, and clays. In addition, the fill contains various anthropogenic materials
including stone fill; brick and concrete fragments; asphalt pavement; railroad tie pieces; coal and ash debris; and
wood, steel, and iron debris. In the former production areas of the Site, NAPL is present within the-fill, primarily/ tin the form of dry weathered creosote. .'^V^ '
Other Quaternary Deposits - Fluvial Quaternary (Pleistocene) deposits overlie the unconsolidated Columbia
Formation, and range in thickness from 0 to approximately 10 to 15 feet, generally decreasing in thickness near
drainage areas. Quaternary deposits are generally comprised of bands of tan and orange-brown iron-stained silts with
lesser amounts of sand, gravel, and clay. These deposits also contain organic matter in the form of roots, peat, reeds,
BLASLAND. BOUCK & LEE. INC.F:\USEFWHLAR99\5739I832 WPO -- 9/30/99 engineers & scientists 1-5
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and other organic debris. Holocene deposits are present in drainageways and marsh areas and consist of silty clay
with lesser amounts of fine sand; thickness ranges from 0 to 6 feet. Only two areas of large grain-sized sediments
(i.e., gravel and cobbles) were observed in the drainageways: one near a wood bridge across Hershey Run (which is
likely fill related to the power lines right-of-way), and one near the mouth of Hershey Run. In the marsh areas, a clay
is present which is described as a drier and firmer clay at depth. This clay unit ranges in depth from 1 to 4 feet below
ground surface, and its thickness ranges from 2 to 5 feet. This "marsh clay" is present in over 95 percent of the
borings advanced below 2 feet or more in depth in the marsh areas. Permeability tests were performed on two
representative marsh clay samples collected using Shelby tubes, with the vertical permeabilities on the order of 10"7
centimeters per second (cm/sec).
Columbia Formation - The Columbia Formation underlying the Site is comprised primarily of silty sands and
gravels with seams and thin beds (up to 2 feet in thickness) of silts. The silt layers appear to be more prevalent in
the Process Area and the Drip Track Area. The thickness of the Columbia Formation varies from 0 to upwards of
approximately 20 to 25 feet, and is generally thicker at the center of the Site near the Process and Drip Track Areas.
This formation underlies the fill and other Quaternary deposits in the upland areas as well as the drainage areas.
Moreover, the Columbia Formation is distinguished from the fill and other Quaternary deposits by larger grain sizes,
absence of anthropogenic and/or organic matter, and relative position in the subsurface. One permeability test was
performed on an undisturbed Shelby tube sample of Columbia Formation sediment, which indicated a vertical
permeability on the order of 10'5 cm/sec.
Potomac Formation - The Cretaceous age Potomac Formation is comprised of silts and clays with medium to fine
sand bodies, and underlies the Columbia Formation throughout the Site. A low-permeability layer is typically
observed at the top of this unit that contains clay, silt, and fine sand. A few borings penetrated 40 to 70 feet of the
Potomac Formation. These borings were referenced in the RI report as SB-602, SB-603, MW-14, and MW-15. In
these borings, the formation alternates between clay layers, silt layers, as well as sand layers (one gravel layer also
was observed). The uppermost clay layer ranged in thickness from 5 to 36 feet in these deeper borings. The Potomac
Formation is distinguished from the Columbia Formation by smaller grain sizes, the presence of the low-permeability
(clay and silt) layer at the contact with the Columbia Formation, color (to some degree), and relative position in the
subsurface. Vertical permeability was measured in four undisturbed Shelby tube samples of the Potomac Formation,
indicating a range in permeability from 10'* to 10"7 cm/sec. \ f < c ° ,j(> •v c e . \',v > < c ' ^ , \ . - >
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1.3.1.2 Hydrogeology
Based on the geologic characteristics of the Site, there are two distinct hydrostratigraphic units present: an upper unit
within the fill, other Quaternary deposits, and the Columbia Formation; and a lower unit within the Potomac
Formation. These units are hydraulically separated by a low-permeability layer (aquitard) consisting of clay and silt
encountered near the upper part of the Potomac Formation. The Potomac aquitard is likely present as a uniform layer
underlying the Site. The top of the Potomac Formation aquitard is present at elevations ranging from approximately
5 feet above mean sea level (AMSL) near soil boring GFP-18 (as determined in the RI report) to approximately -50
feet AMSL near the monitoring well MW-7 cluster. The top of the aquitard appears to have been eroded in the past
(prior to deposition of the Columbia Formation soils) and several potential buried stream channels appear to be
present in the clay. These paleochannels appear to be generally oriented in a north-south direction, and a separate
depression was observed in the top of the clay layer near soil boring SNB-11 A.^>0 .^e<{. c^~-*-\-> *..! \^^prV ?
Upper Hydrostratigraphic Unit - Groundwater in the upper hydrostratigraphic unit was encountered at depths
ranging from approximately 2 feet to 11 feet below grade. Groundwater in the upper unit appears to be unconfined
and, therefore, groundwater in this unit represents water table conditions beneath the Site. Based on the observed
thickness of the fill, other Quaternary deposits, and the Columbia Formation deposits, the saturated thickness of the
upper hydrostratigraphic unit ranges from approximately 5 to 30 feet. Horizontal groundwater flow appears to
predominate over vertical flow within the upper hydrostratigraphic unit.
Results of a groundwater/surface water interface (GSI) study conducted during the RI indicate that groundwater
within the upper hydrostratigraphic unit is influenced by tidal changes within the Christina River and that the average
(net) hydraulic gradient is toward the West Central Drainageway and Hershey Run. Water level variations of up to
approximately 4 feet were observed during the RI, with the highest groundwater elevations measured during high tidal
cycles and the lowest elevations measured during low tidal cycles. During high tides, groundwater in the upper
hydrostratigraphic unit appears to be recharged by surface water in the West Central Drainageway and Hershey Run,
and during low tides groundwater in the upper unit appears to discharge to the West Central Drainageway and
Hershey Run.
Lower Hydrostratigraphic Unit - Groundwater potentiometric levels in the lower hydrostratigraphic unit were
measured at depths ranging from approximately 3 feet to 15 feet below grade. Based on the geologic characterization
and visual observations during drilling activities, groundwater in this lower unit appears to be semi-confined by the
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overlying low permeability layer. The saturated thickness of the lower hydrostratigraphic was not measured during
the RI; however, published regional geologic information for the area indicates the thickness of the Potomac
Formation can be up to 200 feet (Sundstrom and Pickett, 1967).
Potentiometric level variations of up to approximately 2 feet were observed in this unit during the RI, with the greatest
variations observed in monitoring wells located near the Christina River. Results of the GSI study indicate that
groundwater within the lower hydrostratigraphic unit is influenced by tidal changes within the Christina River and
that the average (net) hydraulic gradient is from the lower hydrostratigraphic unit toward the Christina River, West
Central Drainageway, and Hershey Run. The potentiometric flow direction in the lower hydrostratigraphic unit
appears to be generally to the south toward White Clay Creek and the Christina River during both high and low tides.
1.3.1.3 Sediment and Surface Water
Surface water bodies at, and adjacent to, the Site include the Christina River, White Clay Creek, Hershey Run, and
the associated drainage areas. Three man-made ponds also are present in the upland area of the Site (i.e., the Fire
Pond and two South Ponds). The drainageways are channels of intermittent runoff from the Site and adjacent areas.
The fine-grained sediments in the drainage areas suggest these areas are depositional environments. When flowing,
the drainageways discharge into Hershey Run, White Clay Creek, and the Christina River. Drainage from Hershey
Run discharges into White Clay Creek, and flow from White Clay Creek discharges into the Christina River. The
drainage basin for the Christina River, White Clay Creek, and Hershey Run extend to areas other than the Site,
including current and historical industrial and commercial usage areas as well as historical agricultural usage areas.
Three sediment cores were collected from within the Hershey Run Drainage Area, the West Central Drainage Area,
and Churchman's Marsh for the purpose of evaluating sediment depositional rates in, and around, the Site using
geochronologic dating techniques. The Hershey Run Drainage Area in the northwestern portion of the Site is
relatively low-lying. Aerial photographs between July 1937 and June 1989 indicate that, adjacent to the Site, Hershey
Run has generally maintained the same channel geometry and is a stable channel. Allowing for some uncertainty
because of core segmentation, geochronologic dating results indicate a depositional environment with a sedimentation
rate in the range of 0.24 to 0.36 inches per year (in/yr). The West Central Drainage Area is also a relatively low-lying
wetland area, and aerial photographs from the 1960s show that it may have been channelized and drained.
Geochronologic dating data indicate a depositional environment with a sediment deposition rate in the range of 0.12
to 0.25 in/yr. Churchman's Marsh is off-site immediately south of the Site in an extensive wetland area.
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Sedimentation rates for Churchman's Marsh are more difficult to interpret based on the results of the geochronologic
dating; however, the data appear to support a long-term net deposition rate of approximately 0.12 in/yr, interrupted
by a historical disturbance of the upper few inches of the sediment column within the marsh.
Results of the geochronologic dating strongly indicate the long-term depositional nature of both Hershey Run and
West Central Drainage Areas. This depositional nature is not unexpected in light of the low-energy hydraulic
environment of the marshes, which is not conducive to the resuspension of sediments that have deposited. These
areas, although subject to tidal fluctuations in water level, are not part of the stream channel that primarily conveys^ /N
surface water, and thus tend not to scour. In addition, the abundant rooted veigetation in the marshes and sediment
bed provides additional stability and resistance to scour through buffering of higher flow velocities. ^'^ ..v- r \ >
1.3.2 Ecological Characterization
Ecological studies conducted during the RI included surveys of vegetation, soil macroinvertebrates, wildlife, fish,
and benthic macroinvertebrates. The results of these surveys are summarized here, but are provided in greater detail
in the RI report (BBL, 1999) and the ERA (USEPA, 1997a).
1.3.2.1 Terrestrial Habitats
Three different upland cover types have been identified at the Site, totaling approximately 163 acres, including
upland herbaceous "old field" (87 acres), upland scrub/shrub (14 acres), and upland forest (62 acres). The vegetation
survey data indicate that on-site and off-site forested areas have similar species assemblages. For example,
arrowwood seedlings were the most common of 31 herbaceous species on-site, with Japanese honeysuckle, several
goldenrod species, and multiflora rose also prevalent. The off-site ground cover was similar, with Japanese
honeysuckle, goldenrod, and multiflora rose being the predominant species. Several types of soil macroinvertebrate
organisms were observed, with earthworms the most prominent organism, and the species richness (i.e., number of
different types of organisms) at on-site and off-site locations were similar. In addition, numerous other terrestrial
wildlife species (e.g., birds, mammals, reptiles) also were observed on and off site.
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1.3.2.2 Aquatic/Wetland Habitats
A variety of aquatic and wetland habitats were identified at the Site during the RI. Aquatic habitats consist of small
on-site open water ponds (e.g., Fire Pond, South Ponds), and downgradient tidal drainageways and streams (e.g.,
Christina River and Churchman's Marsh, White Clay Creek, Hershey Run Creek and Marsh). Delineated
jurisdictional wetlands cover approximately 136 acres, or 45 percent of the Site, and dominate the southern and
western portions. Non-tidal wetlands occur in the southern portion of the Site, the South Ponds Area, K Area, Fire
Pond Area, and approximately 15 smaller disjunct non-tidal wetlands occupy low-lying areas in the uplands of the
Process and Wood Storage Areas. Tidal wetlands include marshes and drainageways along the southern portion of
the Site. The wetland cover types include freshwater tidal marsh (115 acres), non-tidal emergent wetlands (11 acres),
non-tidal forested wetlands (9 acres), and non-tidal scrub/shrub wetlands (1 acre).
The benthic macroinvertebrate community survey identified a total of 134 different taxa, including two turbellarians
(flatworms), one nemertean (proboscis worm), one nematode (roundworm), 32 annelids (segmented worms), six
aquatic crustaceans, 80 insects, and 12 molluscs. Density (number of individuals) and richness (number of different
types of organisms) varied from station to station. The occurrence and distribution of benthic macroinvertebrates
throughout the southern and western tidal freshwater streams and marshes were, to a large degree, dictated by habitat
features such as flow, availability of an adequate food source, and sediment grain size. Communities with the highest
species richness (i.e., greater than 15 taxa) were stations with fine-grained substrates and high organic content (peat).
These stations were located throughout the tidal freshwater streams and marshes, specifically the East Drainage Area,
East Central Drainage Area, Central Drainage Area, portions of the West Central Drainage Area, Hershey Run,
Christina River, Churchman's Marsh, and White Clay Creek. Most of the stations displayed moderate densities of
macroinvertebrates and a relatively even distribution of dominant taxa.
A fish survey was conducted during the RI at three on-site locations (Hershey Run, East Central Drainage Area, and
West Central Drainage Area) and two off-site locations (Churchman's Marsh and White Clay Creek). The species
observed include species typical of tidal/non-tidal habitats, with on-site and off-site habitats dominated by American
eel, carp, and killifish.
A wetland wildlife survey was conducted and identified similar species at on- and off-site locations. The majority
of differences in species abundance between on-site and off-site stations appeared to be related to the greater open-
water area present off-site. For example, piscivorous bird species that prefer open water, such as the double-crested
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cormorant, common tern, osprey, and white pelicans, were either seen exclusively or more often in the off-site marsh
area than on-site. Conversely, wading birds, such as the great blue heron, great egret, and snowy egret, were more
often seen on-site, particularly in the Hershey Run area.
1.3.2.3 Threatened/Endangered Species
The vegetative survey identified several plants that occur on Delaware's Rare Native Vascular Plant List. These
plants include swamp white oak (Quercus bicolor), sessile leaved tick-trefoil (Desmodium sessilifolium), swamp
milkweed (Asclepias incarnata), and closed gentian (Gentiana andrewsif). These plants are ranked globally and on
the state level. On a global level, each of the plants is ranked as secure (G4 or G5). On the state level, the sessile
leaved tick-trefoil and the swamp milkweed are known to exist within the state, but have not been verified for more
than 15 years. Within Delaware, the closed gentian is extremely rare (five or fewer known occurrences), and the
swamp white oak is very rare (between six and 20 known occurrences). Four plant species that are federally listed
as endangered or threatened may occur in Delaware. These species are swamp pink (Helionas bullata), small whorled
begonia (Isotria medeoloides), Canby's dropwort (Oxypolis canbyi), and Knieskern's beaked rush (Rhynchospora
knieskerni). None of these four species was observed during either on- or off-site vegetative surveys.
Threatened/endangered wildlife species listed by the Delaware Natural Heritage Program include the bald eagle
(Haliaeetus leucocephalus), least tern (Sterna antillarum), bank swallow (Riparia riparia), warbling vireo (Vireo
gilvus), queen snake (Regina septemvittata), and mulberry wing (Poanes massasoit). These wildlife species are
ranked globally and on the state level. On a global level, each is ranked as secure (G4 or G5).
1.3.3 Constituent Nature and Extent
A primary objective of the RI was to determine the nature and extent of constituents present in soil, sediment,
groundwater, and surface water. Air, a drainage pipe, and UST also were investigated. The spatial extent of NAPL
and other constituents including total PAHs, total BTEX (benzene, toluene, ethylbenzene, and xylenes), other VOCs,
SVOCs, pesticides, total PCBs, metals, and dioxin/furans was characterized, with over 100,000 data points generated
during the RI. The results are summarized here and more fully described in the RI report (BBL, 1999).
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1.3.3.1 NAPL Observations
The extent of NAPL in surface soil, subsurface soil, and sediments was evaluated based primarily on visual
observations recorded during the completion of approximately 240 soil borings and collection of 157 sediment
samples during RI activities. Deposits of NAPL were observed in surficial soils of the Upland Area, primarily the
Process, Drip Track, and Wood Storage Areas (Figure 1-3). Other smaller deposits were observed along the access
road leading to the southwest corner of the uplands and in the South Ponds and K Areas. In surface soils of these
areas, NAPL was found in a dry weathered form, typical of creosote and tar-like material that has been significantly
weathered and dried over time. As a result, the material appeared to be immobile and it possessed little detectable
odor. Thickness of the larger deposits ranged from less than 6 inches to approximately 3 feet.
The RI identified 11 discrete zones where NAPL appears to be present in subsurface soils (Figure 1-4). These
subsurface NAPL zones occur under portions of the Process Area, Drip Track Area, Wood Storage Area, and Fire
Pond. Smaller zones are located near the South Ponds Area and K Area. NAPL in subsurface soils was observed
primarily as immobile discontinuous blebs and small, thin seams. Although seams of NAPL saturated soils were
observed under the Process Area and Fire Pond, the zones did not appear to be continuous or interconnected. No
NAPL was observed within the Potomac Formation soils based on visual observations, and no NAPL was inferred
to be present within the Potomac Formation based on groundwater analytical results and comparisons of effective
solubility. Based on the subsurface NAPL delineation methods presented in the RI, the areal extent of the
individual NAPL zones ranged from approximately 2,400 square feet (for the smallest NAPL zone) to 69,600
square feet (for the largest NAPL zone). Collectively, the subsurface NAPL zones sum to an areal extent of
approximately 280,000 square feet (6.4 acres), and the volume of NAPL below the water table within the Columbia
Formation is estimated to be approximately 82,000 cubic yards (cy).
NAPL was observed in surficial (0.0 to 0.5-feet) sediment at 4 of 79 sampling locations, including 3 samples from
the Hershey Run Drainage Area and 1 sample from the West Central Drainage Area (Figure 1-5). When sediment
core results from the 0- to 12-inch sediment horizon are included, an additional five surficial areas are identified. In
subsurface sediments, NAPL was observed at depths greater than 6 feet, but typically in only a portion of the full
length of certain sediment cores. At three locations, NAPL was observed at depths greater than 60 inches (however,
only at location HRD-7R was NAPL identified throughout the full length of the sediment core; cores HRD-1R and
HRD-17M were observed to have NAPL present in only a portion of sediment core samples).
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1.3.3.2 Analytical Results
In addition to identification of surficial weathered NAPL deposits and subsurface NAPL zones, the RI generated
an extensive analytical database for the Site. These data are briefly summarized here and more fully reported in
the RI report (BBL, 1999).
Soil and Sediment Data
• In general, BTEX and other VOCs were either not detected or detected at low total concentrations (< 1 mg/kg) in
soils. While higher BTEX and VOC concentrations were detected in the Process Area (up to 34.53 mg/kg) and
K Area (up to 311 mg/kg), subsurface concentrations below the surficial samples were typically near the analytical
detection limit.
• Similar to the soil sampling results, BTEX and other VOCs were either not detected or detected at low total
concentrations (< 1 mg/kg) in sediments. However, certain sediment samples from Hershey Run, the Central
Drainage Area, and the South Ponds Area had higher concentrations (up to 41.4 mg/kg total BTEX in a South
Ponds Area sample).
• SVOCs, particularly PAHs, tended to be detected in proximity to visible creosote and NAPL deposits.
Concentrations of VOCs decreased to non-detectable levels immediately outside of these deposits.
• Upland soil pesticide concentrations were significantly lower than the sediments surrounding the Site, suggesting
that pesticide concentrations may be a regional sediment issue. The highest pesticide concentration in soil was 0.92
mg/kg of methoxychlor found in the Wood Storage Area, while the sediments surrounding the Site have
concentrations up to 24 mg/kg of 4,4' -DDT (Christina River).
• Similar to pesticides, the surrounding sediments have higher total PCB concentrations (up to 1.3 mg/kg) than the
upland soil areas (up to 0.46 mg/kg), suggesting that PCBs may also be a regional sediment issue.
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• Metal concentrations were typically observed in the various drainageways at higher concentrations than in the
upland areas (see RI Figures 4-8 through 4-19), indicating the elevated metal concentrations may be a regional
sediment issue.
• Metal concentrations did not typically correlate with NAPL locations.
• Dioxin/furan concentrations ranged from not detected in the Process Area to 0.007 mg/kg in the southwest portion
of the uplands. The majority of the other detections in soil and sediment were less than 0.0005 mg/kg, indicating
that dioxin/furan concentrations on-site are low and indicative of a regional issue.
Groundwater Data
• BTEX and other VOCs were detected in groundwater samples from the upper hydrostratigraphic unit near the
Process/Drip Track Area and Wood Storage Area (e.g., up to 3020 Mg/L BTEX and 4730 /^g/L other VOCs in
MW-2A. However, concentrations of BTEX and other VOCs rapidly decrease to non-detect with distance from
potential source areas.
• Similar to BTEX and other VOCs, SVOCs were detected in the vicinity of the former Process Area (e.g., up to
142,780 /ug/L total PAHs in MW-2A), and SVOC concentrations significantly attenuate with distance from
potential source areas.
• Pesticide compounds were detected in the upper hydrostratigraphic unit at concentrations ranging from not detected
to 0.14 /^g/L (4-4'-DDD). No pesticides were detected in the lower hydrostratigraphic unit above the laboratory
method detection limits indicating that the extent of pesticides in groundwater at the Site appears to be limited.
• PCBs were not detected in any Site monitoring wells.
• Metals concentrations in the lower hydrostratigraphic unit are much lower than concentrations of metals in the
upper hydrostratigraphic unit because of the greater heterogeneity of soil types and nearness to land surface.
• Dioxin/furans were only detected in groundwater in one well (MW-2A) from the Process Area at concentrations
of3.9ng/Land 15 ng/L.
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Surface Water Data
• VOCs were not observed in surface water samples obtained at or adjacent to the Site during base flow or storm
flow conditions with the exception of low concentrations of toluene, chloromethane, carbon disulfide, and
bromomethane (ranging from 3 /ug/L to 23 /ug/L).
• PAHs were only detected in one base flow surface water sample from the Fire Pond (973 yug/L), one sample from
the South Ponds (37 /^g/L), and duplicate samples from the Central Drainage Area (12 and 44 jUg/L). None of the
other surface water samples, including those from White Clay Creek and the Christina River, contained any PAHs.
• Chlordane was the only pesticide detected in base-flow surface water at an estimated concentration of 0.01 //g/L
or less. Three other pesticides were detected in low concentrations (<0.02 /^g/L) during storm-flow conditions.
• None of the surface water samples contained PCBs with the exception of an estimated concentration of 0.59 /ug/L
at one location in the Fire Pond.
• Metals in storm-flow surface water samples were similar to base flow conditions, with unfiltered samples typically
having higher concentrations than filtered samples, as noted previously.
• Dioxin/furans were not detected in base-flow surface water with the exception of OCDD (19 ng/L) at one location
in the Fire Pond. No dioxin/furans were detected during storm-flow conditions.
Other Data
• No ambient air particulates were detected in any of the air sampling locations during the RI (i.e., Process Area,
Fire Pond Area, South Ponds Area), and the low concentrations of organic vapors detected using photoionization
detector (PID) methods were consistent with background conditions.
• An abandoned drainage pipe was observed in a north/south orientation between the South Ponds Area and the
Process Area. A single UST also was identified in the vicinity of the Process Area, with residual materials
indicating the tank formerly contained a petroleum-type compound such as diesel fuel.
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1.3.4 Constituent Fate and Transport
Fate and transport of constituents from source areas is controlled by Site geology/hydrogeology, NAPL infiltration,
NAPL residualization, NAPL dissolution in water, diffusion of dissolved constituents, and sorption of dissolved
constituents onto soil particles. As described in the RI report (BBL, 1999), a substantial body of empirical and
chemical evidence indicates that in over 50 years of operation and nearly 30 years since operations ceased, the areal
extent of constituent migration through Site media remains limited to areas close to historic sources. This evidence
is briefly summarized below for Site soils, sediments, surface water, and groundwater.
1.3.4.1 Soils
The creosote NAPL observed on surficial soils is typically a solid crumbly weathered form in the upland areas and
is not expected to migrate under natural conditions. Because weathering of the exposed NAPL results in dissolution,
volatilization, and biodegradation of the lighter constituents, the remaining weathered material is primarily the heavier
PAHs, which are less volatile and less soluble than the lighter PAHs.
Potential migration of NAPL in subsurface soils at the Site is limited to Columbia Formation soils in the areas near
monitoring wells MW-2A and MW-8A. Subsurface soils near monitoring wells MW-2A and MW-8A may contain
some potentially mobile NAPL as shown by accumulations of NAPL within these wells. Thin NAPL-saturated soil
layers were observed within Columbia Formation soils near the Fire Pond and Process Area; however, these
saturated soils did not appear to be interconnected and the NAPL was probably at residual saturation and thus
immobile at this location. NAPL does not appear to be mobile in subsurface soils across the remainder of the Site,
as indicated by the following observations:
• There does not appear to be a significant source of NAPL or NAPL mass concentrated anywhere at the Site that
would provide sufficient pressure to cause subsurface NAPL migration.
• Where present in Columbia Formation soils, NAPL was observed as discontinuous blebs or small, thin seams,
indicating that NAPL for the most part is at residual saturation and generally immobile.
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Vertical migration of NAPL in subsurface soils is limited due to the presence of the low-permeability aquitard
present near the top of the Potomac Formation. The aquitard is a sufficient capillary barrier that prevents
downward NAPL migration. This conclusion is supported by the observation that no visual or chemical evidence
has been uncovered that indicates the presence of NAPL in Potomac Formation soils. Furthermore, since the
density of creosote is only slightly higher than water, the entry pressure exerted by NAPL below the water table
is likely not high enough for the NAPL to invade the aquitard.
1.3.4.2 Sediment/Surface Water
Sediment transport at the Site appears to be limited by the physical nature of the drainage areas and the location
of NAPL within the sediment horizon. The configuration of the drainageways, grain size of the sediment,
geochronologic dating data, and visual observations indicate that the drainage areas at the Site are depositional.
Ten of the 157 sediment samples had visible surficial NAPL materials in the 0- to 6- or 0- to 12-inch intervals.
These 10 samples were located in Hershey Run and the West Central Drainage Area. Additional cores at the
nearest sampling location showed a lack of surficial NAPL, suggesting that the areal extent of NAPL near the
surface is limited. Geochronologic dating suggests that the existing surficial sediments (approximately 3- to 9-inch
depth) contain sediments that have accumulated since the early 1960s. These sediments are relatively free of NAPL
material in comparison to the deeper historical sediments (pre-1960s).
Dissolution into the water column would potentially occur in certain areas where the remaining creosote-related
constituents are at, or near, the sediment/surface water interface. However, PAHs were not observed in the water
column during either base-flow or storm-flow conditions in Hershey Run or the West Central Drainage Area.
Because creosote constituents such as PAHs generally have low water solubilities and bond to sediments as a result
of their hydrophobic nature and strong affinity to organic carbon in particulate matter, partitioning of these
compounds into the water column is limited.
1.3.4.3 Groundwater
Dissolved creosote-related constituents were observed in upper hydrostratigraphic unit groundwater only in the
immediate vicinity of subsurface NAPL in the Process Area and Fire Pond Area; constituents were not detected in
groundwater at the southern perimeter of the Site. In fact, the groundwater constituents at the Site exhibit a
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significant decrease in concentration along the flowpaths downgradient of the former operations areas. Considering
the length of time (nearly 30 years) since operations have ceased, this lack of PAHs and BTEX migration is strong
evidence that natural attenuation mechanisms have limited the movement of these constituents in groundwater.
1.3.5 Summary of Cultural Resources Surveys
During the RI, cultural resources were evaluated at the Site pursuant to the National Historic Preservation Act
(NHPA) and in accordance with Delaware State Historic Preservation Office guidelines. The first step in evaluating
cultural resources was a Phase IA Cultural Resources Survey, which gathered information on prehistoric
archaeological sites and historical information and documentation of occupation and use of the property. The Phase
IA Survey consisted primarily of reviewing geological, archaeological, and historical literature regarding cultural
resources in the area, with some limited on-site field work. The Phase IA report presented a prehistoric site
sensitivity model indicating the probable presence of intact prehistoric archaeological sites; the model was modified
based on a geoarchaeological study of aerial photographs and a review of soil data collected during the RI. The
report identified two areas of prehistoric occupation (14,000 to 350 years before present) and four historic (1630
to present) archaeological sites (MAAR Associates, 1995). One of the historic sites had been previously reported
and one, recorded as a standing structure, had been used by the wood-preserving companies as an office. Sensitivity
models were presented for both prehistoric and historic archaeological sites. In general, the areas along the
drainages within and bordering the property were considered highly to moderately sensitive for prehistoric
archaeological resources, while the majority of the upland areas were considered low in sensitivity.
The next step in evaluating cultural resources was a Phase IB Survey to provide more detailed information about
the extent of prehistoric and historic resources on portions of the Site with the potential for active remediation,
chiefly the process Area and Wood Storage Area. The Phase IB Survey consisted of small excavations placed at
intervals across the Site based on the prehistoric site sensitivity model developed during the Phase IA Survey.
Eight additional prehistoric archaeological sites were identified during the field survey. Only three of the prehistoric
archaeological sites (Site 3, Site 5, and Site 7) likely to be affected by active remediation possess sufficient
integrity to warrant further consideration. The remaining seven prehistoric archaeological sites either lack integrity
or are outside of the area likely to require active remediation. Three historic archaeological sites (the Lynam Farm
Complex, the Worker Housing Site, and the Wright Farm Complex) were recommended for further evaluation if
subject to active remediation. Thus, as a result of the Phase IB archaeological field survey, Phase II evaluation of
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six archaeological sites was recommended. The Worker Housing Site coincided with prehistoric Site 7, so that five
areas of archaeological potential are represented.
The three potentially significant prehistoric sites were Site 3, Site 5 and Site 7. Prehistoric Site 3 is located in the
south central portion of the Upland Area and may be disturbed if remedial action is warranted in the South Pond
Area or West Central Drainage Area. Prehistoric Site 5 is located along White Clay Creek and may be disturbed
if remediation is necessary near that portion of the Creek or in the West Central Drainage Area. Prehistoric Site
7 is collocated with the Worker Housing historical site, and both sites could be disturbed if remedial action is taken
in the southwest corner of the Wood Storage Area or the southeastern portion of the Hershey Run Drainage Area.
The remaining two historical sites were the Lynam Farm Complex and the Wright Farm Complex. The Lynam
Farm is located in the southwest portion of the Wood Storage Area and could be disrupted if remediation is
warranted in this portion of the Site. The Wright Farm Complex is located near the K Area and could be disturbed
if remedial activities are needed in the area.
1.4 Summary of Baseline Risk Assessments
1.4.1 Human Health Risk Assessment
A baseline HHRA for the Site was performed by Environmental Standards, Inc. (ESI, 1997) to characterize and
quantify potential risks to human health associated with potential exposure to constituents present at the Site.
The following exposure scenarios were evaluated in the HHRA:
• Current and future adolescent trespassers potentially exposed to constituents in surface soils, non-river surface
water, non-river sediments, Hershey Run surface water, Hershey Run sediment, and NAPL;
• Current and future adolescent swimmers potentially exposed to constituents in Christina River and White Clay
Creek surface water and sediment;
• Current and future anglers potentially exposed to constituents in locally caught fish;
• Future construction workers potentially exposed to constituents in surface and subsurface soils; and
• Future industrial workers potentially exposed to constituents in surface soils, NAPL, and groundwater.
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The risk characterization portion of the HHRA concludes that a potential risk may exist for anglers that choose to
consume locally caught fish in amounts greater than specified by existing fish consumption advisories. However,
this potential risk is attributed to the regional presence of PCBs in the watershed and, specifically, the Christina River
and White Clay Creek. Results of the RI indicated that PCBs in on-site media were either not detected or observed
in very low concentrations (i.e., <1.0 ppm). Hazard indices calculated for non-carcinogenic effects indicate potential
for concern associated with future on-site workers inhaling dust and airborne particulates that could be generated
during future construction activities. However, the HHRA explains that this concern is attributed to the presence of
manganese, a naturally occurring element, and can be readily mitigated during construction through the use of
appropriate safety equipment and procedures. Under a hypothetical future scenario, a potentially unacceptable risk
was also associated with ingestion of groundwater containing NAPL-related constituents, should such exposure be
allowed to occur in the future. Other than these potential receptors and exposure pathways, the HHRA confirms that
there are no appreciable Site-related human health risks warranting further concern.
1.4.2 Ecological Risk Assessment
USEPA conducted the ERA for the Site (USEPA, 1997a) as part of the RI. The objectives of the ERA for the Site
include:
• Identify relevant constituents of potential concern (CoPCs);
• Characterize the potential risk to selected (representative) receptor species relative to CoPC concentrations in
various environmental media (abiotic and biotic);
• Develop site-specific ecotoxicity thresholds for sediment and soil; and
• Identify areas of potential concern at the Site.
Receptors considered for the ERA included wetland vegetation, benthic invertebrates, fish and amphibians, the soil
community, terrestrial vegetation, and birds and mammals. Sediment and soil solid-phase toxicity tests were
performed with five test species. The abundance and kinds of plants and animals occurring on the Site were also
characterized.
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Environmental data to support this ERA were collected in three phases as documented in the RI report (BBL, 1997).
Surface sediments, soils, and water, as well as aquatic and terrestrial biota, were analyzed for selected organic
compounds and metals.
1.4.2.1 Overview of the Risk Assessment Approach
The ERA for the Site was conducted in accordance with technical guidance from USEPA (USEPA, 1992; 1997b),
and followed four steps: 1) problem formulation; 2) exposure assessment; 3) effects assessment; and 4) risk
characterization. Detailed discussion and results of this process are provided in the ERA (USEPA, 1997a) and are
summarized below.
Potential Receptors - Representative receptors were selected by USEPA to evaluate the various Site communities
that may potentially be exposed to CoPCs. Representative receptors for the benthic macroinvertebrate community
are the freshwater amphipod Hyallela azteca and the midge larva Chironomus tentans. The fish community is
represented in this assessment by the mummichog (Fundulus heteroclitus). The representative receptor for the
amphibian community is the leopard frog (Rana pipiens). The wetland communities as a whole are represented
by the macroinvertebrates, fish, and amphibian species described above. In addition, the wetland communities are
evaluated on the basis of vegetation surveys of wetland plants. The soil macroinvertebrate community is
represented by the earthworm (Eisenia foetida). The terrestrial plant community is evaluated on the basis of
vegetation surveys of upland forest, shrub/scrub, and herbaceous habitats. Piscivorous birds are represented by the
snowy egret (Egretta thuld), worm-eating birds are represented by the American robin (Turdus migratorius), and
carnivorous birds are represented by the northern harrier (Circus cyaneus). Carnivorous mammals are represented
by the mink (Mustela visori) and the short-tailed shrew (Blarina brevicauda), and raccoons (Procyon lotor) were
selected to represent omnivorous mammals at the Site.
Assessment and Measurement Endpoints - Assessment endpoints were selected by USEPA to assess the potential
for adverse effects on ecological components of the aquatic and terrestrial food webs. The 12 assessment endpoints
evaluated were:
1. Protection of the structure and function of the wetland communities;
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2. Protection of the structure and function of aquatic benthic communities;
3. Protection of the upland soil community functioning;
4. Protection of the structure and function of the terrestrial plant community;
5. Protection offish populations and communities from direct toxicity and reproductive impairment;
6. Protection of the populations of amphibians, specifically in terms of recruitment;
7. Protection from direct toxicity and reproductive impairment of piscivorous birds using the Site;
8. Protection from direct toxicity and reproductive impairment of worm-eating birds using the Site;
9. Protection from direct toxicity and reproductive impairment of carnivorous birds using the Site;
10. Protection from direct toxicity and reproductive impairment of carnivorous mammals using the Site;
11. Protection from direct toxicity and reproductive impairment of omnivorous mammals using the Site; and
12. Protection from direct toxicity and reproductive impairment of terrestrial herbivores using the Site.
Measurement endpoints and their relationships to assessment endpoints are summarized in Table 1-1. This table
also shows the weight-of-evidence approach as presented in USEPA's ERA. The priority given to each
measurement endpoint indicates the use of the data in the weight-of-evidence evaluation. The results of field
surveys were given the highest priority in interpreting the potential for effects on the structure and function of
aquatic, wetland, and soil communities. Toxicity test results were the primary data used to evaluate the potential
for effects on fishes and amphibians, and they were used as secondary lines of evidence for evaluation of benthic
community effects. Toxicity measurement used to evaluate the various assessment endpoints were derived from
solid-phase toxicity tests for sediment samples using the freshwater amphipod (Hyallela aztecd), the midge
(Chironomus tentans), the mummichog (Fundulus heteroclitus), and the African clawed frog (Xenopus laevis).
Toxicity tests for soil samples were conducted using the earthworm (Eisenia foetidd). Exposure models and
toxicity reference values from the literature were used to evaluate transfer of CoPCs through food webs and
potential risk of direct toxicity and reproductive impairment in birds and mammals. Bioaccumulation studies
conducted with fish, earthworms, and small mammals provided data for the exposure models.
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CoPCs - PAHs are the primary CoPCs at the Site, and are the focus of this FS. Based on comparison to benchmarks
for sediment, soil, and water, USEPA also identified arsenic, cadmium, chromium, copper, lead, mercury, zinc, PCBs,
PCP, DDT, and volatile organic compounds as potential CoPCs for the Site and evaluated these constituents in the
ERA. Metals identified as CoPCs are not associated with historical site-related activities. In general, metals
concentrations that exceed conservative screening criteria are localized. Most exceedances occur off-site or on the
periphery of the Site, suggesting that metals are a regional issue and off-site sources may therefore contribute to the
detection of metals on-site.
1.4.2.2 Evaluation of Assessment Endpoints
Exposure and effects data for the Site were analyzed relative to the 12 assessment endpoints described above. Risk
assessment results for each receptor population are summarized below by assessment endpoint (also see
Figure 1-6).
Structure and Function of the Wetland Communities - Overall, the wetland vegetation community is dense,
diverse, and not apparently affected by CoPCs. An absence of vegetation observed in isolated areas with visible
weathered creosote on the surface may be due to physical inhibition of plant growth by the hardened surface created
by creosote. The benthic community data were difficult to compare because of the lack of collocated chemistry
data. However, there may be some effects on the benthic community at isolated areas of the Site (e.g., upper
Hershey Run). These effects could result from an absence of suitable habitat, negative effects of CoPCs, or a
combination of both elements. Toxicity test results confirm areas of localized sediment toxicity to benthic
invertebrates.
Structure and Function of Aquatic Benthic Communities - Benthic community analyses based on field collected
samples do not indicate any significant community-level effects, even in areas with elevated total PAH
concentrations. Sediment toxicity tests suggest localized areas of elevated toxicity. The ERA found significant
correlations between metals concentrations and adverse effects for beryllium, cadmium, copper, mercury, thallium,
vanadium, and zinc; thus, these metals may be having some effects. However, because of the masking effects of
PAHs in the toxicity tests, only unbounded no observed adverse effect levels (NOAELs) could be determined for
these metals. Overall, the potential risk to benthic aquatic communities is relatively small and confined to localized
areas of very high PAH concentrations.
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Upland Areas Community Functioning - Qualitative field observations of soil macroinvertebrates do not indicate
adverse effects, but the observations are insufficient to characterize potential risk for the entire Site. Earthworm
survival or growth was negatively affected in two of the soil samples tested. The toxic effect range, the NOAEL
to the lowest observed adverse effect level (LOAEL), for total PAH concentrations was calculated at 587 to
1,264 mg/kg. Toxic effects were presumed due to PAHs, but some metals concentrations (antimony, arsenic,
copper, lead, mercury, nickel, and zinc) were also correlated with earthworm survival, although only unbounded
NOAELs could be determined for these metals. Terrestrial vegetation is absent from areas of the Site with visible
weathered creosote at the surface. It is unclear if the latter is due to potential toxicity or a hardening of the surface
soil by the weathered creosote. Overall, impairment of soil community functioning is minor and limited to small
areas of the Site.
Structure and Function of the Terrestrial Plant Community - A qualitative assessment of plant community data
does not indicate widespread adverse effects onsite. There is evidence of past disturbance and subsequent
herbaceous revegetation in former processing areas of the upland habitat. There is also evidence of an absence of
vegetation in areas with visible weathered creosote at the surface. It is unclear if the latter is due to potential
toxicity or a hardening of the surface soil by the weathered creosote.
Direct Toxicity and Reproductive Impairment of Fish Populations and Communities - Qualitative observations
of fish species onsite indicate the presence of species expected for the habitats found at the Site and functional
reproductive populations of some species, including the designated representative receptor, mummichog. The data
generated from fish embryo toxicity assays were of insufficient quality to quantitatively assess potential risk to fish
posed by tested sediments. Qualitatively, the toxicity threshold for sediment total PAH effects to fish (NOAEL
of 197.6 and LOAEL of 1,106 mg/kg dry weight) appears to be an order of magnitude higher than that estimated
for benthic invertebrates (NOAEL of 82.8 and LOAEL of 197.6 mg/kg dry weight). Food chain exposure models
for fish indicated a potential risk associated with total PAHs, PCBs, and chromium in Hershey Run, the Central
Drainage Area, and the West Drainage Area, as defined by exceedances of NOAELs. However, when realistic
input parameters were used such as site-specific bioaccumulation factors (BAFs) and comparison to LOAEL in
place of NOAEL, only PCBs resulted in a hazard quotient greater than 1. The high PCB concentrations in forage
fish at the Site are indicative of a regional problem and are not correlated with PCB concentrations in sediment on
site, suggesting that bioaccumulation of PCBs in forage fish collected at the Site is driven by off-site exposures.
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Overall, potential risk to fish populations at the Site appears to be low to moderate, and localized in areas of the
Site with the highest PAH concentrations. This potential risk is driven primarily by potential indirect effects on
benthic organisms that are important food resources for fish.
Populations of Amphibians and Recruitment - The data generated from the frog toxicity assays were of
insufficient quality to accurately quantify potential toxicity of tested sediments. Qualitatively, frogs appear to have
similar sensitivity to sediment PAHs as fish and lower sensitivity than tested benthic invertebrates. Qualitative
observations of amphibian species on site indicate the presence of species expected for the habitats found at the
Site and functional reproductive populations of some species, including the designated representative receptor
leopard frog.
Direct Toxicity and Reproductive Impairment of Birds and Mammals Using the Site - Potential risk of Site
CoPCs to birds and mammals was estimated based on comparison of exposure point concentrations to toxicological
benchmarks (NOAELs and LOAELs). Screening-level food-web exposure modeling indicated that the potential
for ecological risk exists for arsenic, lead, chromium, zinc, PAHs, and PCBs based on comparison to NOAEL
values. However, when exposure concentrations were compared with LOAEL values and site-specific input
parameters were used, the only potential for risk was to worm-eating birds (robins) exposed to lead off site at Bread
and Cheese Island.
1.4.2.3 Ecotoxicity Thresholds
The aquatic assessment endpoints were more sensitive than the terrestrial assessment endpoints with respect to the
calculated NOAELs and LOAELs for PAHs. For aquatic assessment endpoints, the NOAEL was calculated to be
82.8 mg/kg and the LOAEL was calculated to be 197.6 mg/kg. The corresponding NOAEL and LOAEL values
for terrestrial assessment endpoints were 587 mg/kg and 1,264 mg/kg, respectively. Based on these results, USEPA
proposed preliminary remedial action objectives (RAOs) of 600 mg/kg for soil and 150 mg/kg for sediment.
A different ecotoxicity threshold, the EC25 concentration, is believed to provide a more consistent and reliable
estimate of a potential level of effect than the NOAEL or LOAEL. In response to discussions with USEPA,
Exponent provided a rationale to USEPA for selecting ECjj values as remedial action objectives (PTI, 1997a). In
an accompanying technical memorandum (PTI, 1997b), Exponent provided USEPA with a reanalysis of sediment
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and soil toxicity data for the Site and a derivation of EC25 values. The table below summarizes these ecotoxicity
thresholds developed from data collected at the Site.
Toxicity-test-derived Toxicity Thresholds for Total PAHs (TPAH)
MediumSedimentSoil
Effect Concentration BasisChironomid 14-day mortality EC25
Earthworm 28-day mortality EC25
mg TPAH/kg
(dry weight)364925
mg TPAH/kg
(organic carbon)33,70048,900
Some unexpected complications were uncovered when the preliminary RAOs developed by USEPA and the EC25
values developed by Exponent were compared. Because the first round of sediment toxicity tests failed quality
assurance checks, new composites were prepared from the original samples for a second set of toxicity tests. A
second set of chemical analyses was also conducted on this new set of sediment samples. In developing the EC2J
values, Exponent paired the first set of chemistry data with the second set of toxicity test results, whereas USEPA
used the second set of chemistry data. Upon discovering this difference, Exponent compared the chemistry data
from the two sets and found them to be comparable within the range of analytical variability. However, slight
discrepancies in the PAH data resulted in some differences in the LOAEL values determined by Exponent and
USEPA. The paired data sets evaluated by Exponent exhibited a monotonic increase in toxic response as
concentration increased, as would be expected if PAHs were causing toxicity. The data sets used by USEPA did
not share this feature.
The original analysis conducted by Exponent was retained for use in this report because: 1) the chemical
comparison suggested the two data sets were sufficiently similar that they could be used interchangeably; 2) the
monotonic increases in PAH concentration and toxicity are consistent; and 3) the EC25 value is based on all of the
toxicity data for a given endpoint. Ultimately, the stations with PAH values exceeding EC25 values are spatially
similar to those identified using USEPA's preliminary RAOs. For sediments, the stations were identical. For soils,
USEPA's preliminary RAOs identified 9 stations, rather than the 7 stations identified by the EC^ values (Exponent,
1997b).
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2. Development of Remedial Action Objectives andGeneral Response Actions
2.1 Overview
Taking into account the results of the RI and risk assessments, this section focuses on developing RAOs and an array
of GRAs needed to screen potential remedial technologies (in Section 3) and assemble specific remedial alternatives
for detailed and comparative evaluations (in Sections 4 and 5). To develop RAOs, this section first reviews the
various ARARs for the Site (Section 2.2) and then explains the development of the RAOs (Section 2.3). Section 2.4
describes the specific geographic areas and Site media (including preliminary estimates of material volumes)
potentially subject to remediation. Specific GRAs for the Site are described in Section 2.5.
2.2 Identification and Rationale for ARARs and ARAR Waivers
To the extent practicable, remedial actions must comply with the requirements of federal, state, and local
environmental laws (USEPA, 1998). These regulatory requirements are termed ARARs (i.e., applicable, or relevant
and appropriate requirements). ARARs may be either "applicable," or "relevant and appropriate," but not both.
Consequently, ARARs are identified on a site-specific basis by first determining whether a given requirement is
applicable, then, if it is not applicable, determining whether it is relevant and appropriate.
Applicable requirements are those remedial standards, standards of control, or other substantive environmental
protection requirements or limitations promulgated under federal, state, or local law that address a specific problem
or situation at a site. In contrast, relevant and appropriate requirements are promulgated environmental protection
standards, requirements, or limitations which, while not applicable to a particular site problem or situation, may be
sufficiently similar to warrant their use.
In addition to ARARs, state and federal advisories also exist. Because these items are not binding as promulgated
regulations or laws, they are referred to as "to be considered" (TBCs) and are not required to be complied with, but
may be considered in the absence of specific requirements.
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The identification of site-specific ARARs is based on the particular chemicals at a site, the various remedial actions
proposed, and the general characteristics of a site. As such, ARARs are classified into three general categories:
1. Chemical-specific ARARs, which are specific to the type(s) of constituents present at a site;
2. Action-specific ARARS, which are performance or design requirements of specific technologies or activities
being considered for site remediation; and
3. Location-specific ARARs, which place restrictions on actions based on location of a site or areas of special
interest within a site such as areas containing ecologically sensitive habitats, threatened/endangered species,
or archaeologically significant artifacts.
Table 2-1 provides a list of the ARARs and TBCs considered for the Site, along with a brief assessment and rationale
for their applicability or relevance and appropriateness. Note that the ability to comply with ARARs is a component
of the development and detailed evaluation of remedial alternatives. The identification of a recommended remedial
alternative may invoke the applicability of other ARARs to be addressed during the remedial design and
implementation phases.
Under certain circumstances, it may be infeasible, impracticable, or impossible to achieve all ARARs identified for
a site. To address such cases, Section 300.430(f)(l)(ii)(c) of the NCP identifies six circumstances under which
ARARs may be waived (USEPA, 1988):
1. The alternative is an interim measure and will become part of a total remedial action that will attain the applicable
or relevant and appropriate federal or state requirement;
2. Compliance with the requirement will result in greater risk to human health and the environment than other
alternatives;
3. Compliance with the requirement is technically impracticable from an engineering perspective;
4. The alternative will attain a standard of performance that is equivalent to that required under the otherwise
applicable standard, requirement, or limitation through use of another method or approach;
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5. With respect to a state requirement, the state has not consistently applied, or demonstrated the intention to
consistently apply, the promulgated requirement in similar circumstances at other remedial actions within the
state; or
6. For Fund-financed response actions only, an alternative that attains the ARAR will not provide a balance between
the need for protection of human health and the environment at the site and the availability of Fund monies to
respond to other sites that may present a threat to human health and the environment.
Of these six sets of circumstances under which an ARAR may be waived, at least one is considered applicable to the
Site: "Compliance with the requirement is technically impracticable from an engineering perspective." The RI
identified several Site locations where seams of NAPL were present in subsurface soils, primarily associated with
the Process Area. In addition, dissolved-phaseNAPL-related constituents (e.g., PAHs) were detected in groundwater
near these subsurface NAPL zones. While research and experience over the past decade have shown that partial
NAPL removal may be possible at some sites, recovering NAPL from deep below the water table in volumes
sufficient to restore groundwater and achieve chemical-specific or other ARARs and RAOs is not technically
practicable (USEPA, 1993; 1997c).
Given the geologic setting of the Site; the subsurface location, volume, and physical characteristics of the creosote
NAPL; and the RI data that suggest constituents in groundwater are being naturally attenuated with distance from
source areas, it is appropriate that a technical impracticability (Tl) waiver be granted for this Site to address the
presence of NAPL in subsurface soils and its associated impacts on groundwater. The rationale for this conclusion
and the site-specific requirements needed to perform a Tl evaluation and obtain a Tl waiver, based on USEPA's
Guidance for Evaluating the Technical Impracticability of Ground-Water Restoration (USEPA, 1993), are further
discussed in Section 3.3.3 regarding screening of technologies potentially applicable for addressing groundwater.
2.3 Remedial Action Objectives
RAOs are media-specific goals for protecting human health and the environment. Potential ecological risk, not
human health, is the primary risk management consideration for the Site. As discussed in Section 1.4.2, potential
ecological risks associated with 12 different assessment endpoints were evaluated using a variety of measurement
endpoints. A weight-of-evidence approach, which included the assignment of priority to the different measurement
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endpoints, was used to assess overall potential risk to the ecological components of the aquatic and terrestrial food
webs that are represented by the different assessment endpoints (summarized in Section 1.4.2). Subsets of the
assessment endpoints were determined to have potential ecological risks. These assessment endpoints embody the
key technical considerations in the management of potential Site risks.
Two types of criteria were applied to the Site to characterize and/or manage potential risk:
• Narrative RAOs - Narrative RAOs were used to set the long-term goals for protecting human health and the
environment. The assessment endpoints used for the ERA were used to guide the development of the RAOs.
These goals can be achieved by preventing exposure to constituents that may pose an unacceptable risk.
• Ecotoxicity Thresholds - Ecotoxicity thresholds (i.e., EC25 values) for soil and sediment were derived from
synoptic chemistry (total PAH) and toxicity data collected at the Site. These site-specific effects thresholds
were used to identify areas where remedial action may be warranted, which correlate with areas of known
NAPL deposits and areas identified by USEPA.
Ecotoxicity thresholds for soil and sediment are summarized in Section 1.4.2. These ecotoxicity thresholds are
applied to the Site to identify areas potentially subject to remediation (in Section 2.4).
The RAOs developed for sediment, soil, and groundwater at the Site are as follows:
Sediment
• Reduce potential unacceptable risks to the structure and function of the benthic macroinvertebrate community
• Minimize disturbance to the existing wetland plant community
Soil
Reduce the spatial extent of weathered NAPL (physically disturbed) areas located at or near the soil surface
Minimize disturbance to the existing terrestrial plant community
Prevent the future exposure of industrial workers to soil with potential unacceptable risk
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Groundwater
• Prevent the future exposure of human receptors to groundwater containing NAPL
The sediment RAOs are based on the conclusions of the ERA as summarized on Figure 2-1. Toxicity test results
indicate that some species of benthic macroinvertebrates may be at potential risk of individual-level effects in those
areas of the Site that have the highest PAH concentrations; however, benthic community analyses did not indicate
any significant community-level effects. The representative benthic macroinvertebrates used for the toxicity tests
appear to be more sensitive than those used for fish and amphibian (species that were also tested), suggesting that
this RAO is protective offish and amphibian communities. Any remedial action for sediment should minimize
disturbance to the wetland plant community and limit the potential for invasion by exotic species (this is further
discussed in Section 2.4).
The soil RAOs are based on the outcomes of the ERA (Figure 2-1), as well as the need to ensure that remedial
actions protect future Site uses. The surface soils in certain upland areas containing weathered NAPL deposits are
observed to have an absence of vegetation; however, valuable and diverse terrestrial plant communities inhabit
much of the Site. The third soil RAO addresses a conclusion of the HHRA, which indicated that exposure to
subsurface soils containing NAPL or other CoPCs by future industrial workers could occur. To achieve this RAO,
a Site remedy must prevent such potential future exposure.
The groundwater RAO is also based on hypothetical future Site uses. The RI concluded that NAPL was not
migrating and that dissolved-phase constituents were being rapidly attenuated outside of potential source areas.
Moreover, the HHRA concluded that Site-related groundwater did not currently pose a risk to human health;
however, future use of groundwater could pose potential risks if unacceptable exposure were to occur. This RAO
reflects the need to prevent exposure to NAPL-bearing groundwater under conditions of future industrial use.
2.4 Areas Potentially Subject to Remediation
Results of the RI and baseline human health and ecological risk assessments support the identification of certain Site
areas and associated media (e.g., soil, sediment) where remediation may be warranted. These areas then become the
focus of the GRAs and remedial alternatives. The basis for identifying and characterizing areas potentially subject
to remediation is described in the following sections.
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2.4.1 Upland Area
The initial characterization of areas of weathered NAPL deposits on surface soils (which consists of several
noncontiguous upland areas primarily in the Process, Drip Track, and Wood Storage Areas) was determined from
reconnaissance surveys conducted during the RI (Figures 1 -3 and 2-2). The extent of some sub-areas was confirmed
by comparing PAH levels in soil samples collected adjacent to the weathered NAPL deposits to the ecotoxicity
thresholds (EC25) developed for soil. In all cases, surface soil toxicity predicted using ecotoxicity thresholds was
absent at locations adjacent to the deposits of visibly weathered NAPL.
Certain portions of the Upland Area are also of concern because of NAPL zones present in subsurface soil.
According to the HHRA, exposure and potentially unacceptable risk to construction workers could occur in the future
if these NAPL zones are disturbed during remedial action or future industrial land use. Similarly, future use of
groundwater associated with these subsurface NAPL zones could pose unacceptable potential risk if not mitigated.
As discussed in Sections 2.2 and 3.3.3, remediation of the subsurface NAPL zones and associated groundwater is
considered technically impracticable.
Other aspects of the Upland Area may influence the evaluation and selection of a preferred remedial alternative. For
example, habitat type and quality, plant community status, wildlife species diversity, ecological importance/function,
landscape/regional importance, and the presence of significant archeological and cultural resources for the upland
areas are described in Table 2-2.
2.4.2 Drainage (marsh) Areas
Results of the ecological characterization conducted during the RI, and additional field work conducted by Schuyler
and Johnson (1997), confirm that wetlands on the Site have high regional importance, which could be jeopardized
by disturbance during potential remedial activities. In particular, the Hershey Run Drainage Area and West Central
Drainage Area have relatively high ecological value, and Schuyler and Johnson found that the East and West
Central Drainage Areas had the greatest plant diversity of all wetlands on the Site. An important habitat type in
the West Central Drainage Area (and other on-site marshes) was the locally abundant Schoenoplectus fluviatilis
(river bulrush) emergent marsh. Field observations made by Schuyler and Johnson indicate that the Site (especially
the West Central Drainage Area) supports some of the highest quality and most extensive stands of Schoenoplectus
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fluviatilis found in the Delaware Estuary drainage. This is a natural community of significance in Delaware, with
a current rarity rank of S2, meaning it is very rare (typically 6 to 20 known occurrences) and susceptible to
extirpation. Significant disturbance of this endangered community (e.g., through potential remedial measures such
as sediment removal or capping) would have severe and unacceptable detrimental effects on wetland quality either
through physical destruction of important plants and habitat or by enhancing invasion of Phragmites into areas
disturbed by remedial activities. In addition, disturbance of Site drainage areas (marshes) would conflict with the
associated RAOs for sediment.
Although sediment concentrations of total PAH exceeded ecotoxicity thresholds at a few noncontiguous locations
in a small section of the West Central Drainage Area (Figure 2-2), the area contains limited NAPL material
(approximately 5,000 cy) and is considered to pose only limited potential ecological risk. No areas of the Hershey
Run marsh have total PAH concentrations that exceed ecotoxicity thresholds (Figure 2-2). For these reasons, the
Hershey Run and West Central Drainage Areas are not considered potentially subject to remediation. The limited
sediment toxicity, relatively inaccessible location, and the fact that these wetlands are functionally intact suggest that
intrusive remedial actions (e.g., excavation, capping) should not be performed in these areas. If necessary, a more
detailed assessment could be performed during Remedial Design to compare the potential for adverse impact
associated with actively remediating drainage areas versus allowing exposure to the existing NAPL (where present)
to be reduced through natural recovery processes, which would avoid disruption to the structure and function of
wetlands on the Site.
2.4.3 Hershey Run
A portion of the Hershey Run channel was identified as an area potentially subject to remediation. For the purpose
of the FS, this area was conservatively estimated to extend from adjacent to the Fire Pond to near the confluence with
White Clay Creek (Figure 2-2). The sediment volume potentially subject to remediation in Hershey Run
(approximately 100,000 cy) was estimated by comparing concentrations of total PAH in sediment to the sediment
ecotoxicity thresholds, and by evaluating visual observations of NAPL identified during the RI.
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2.4.4 Fire Pond
The Fire Pond was determined to be an area potentially subject to remediation because one of the four sediment
samples collected in the pond exceeded ecotoxicity effects thresholds (Figure 2-2). Direct measurements of sediment
from this location also indicated potential toxicity. Visual observations of sediment and surface water from the Fire
Pond indicate the presence of NAPL.
Other aspects of the Fire Pond that may influence the evaluation and selection of a preferred remedial alternative are
summarized in Table 2-2.
2.4.5 South Ponds
The South Ponds were determined to be an area potentially subject to remediation based on the exceedance of soil
and sediment ecotoxicity thresholds (Figure 2-2). Some surface soil adjacent to the South Ponds was delineated in
the RI as containing weathered NAPL deposits. For the purposes of the FS, it is assumed that the South Ponds Area,
including adjacent soil, may warrant remediation.
Other aspects of the South Ponds that may influence the evaluation and selection of a preferred remedial alternative
are summarized in Table 2-2.
2.4.6 K Area
A small (0.5-acre) portion of the K Area was included as an area potentially subject to remediation based on visual
observations and a single exceedance of a soil ecotoxicity threshold (Figure 2-2). Other aspects of the K Area that
may influence the evaluation and selection of a preferred remedial alternative are summarized in Table 2-2.
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2.4.7 Summary of Areas and Volumes
The Site location and associated media and material volumes potentially subject to evaluation within this FS are
summarized below. Cubic yard (cy) volume estimates were calculated using volumetric methods based on RI data,
and are therefore preliminary estimates subject to further refinement during remedial design. Volume estimates
were determined as the product of the area and average depth over which NAPL was observed during the RI (BBL,
1999) for each of the locations.
Summary of Areas/Volumes Potentially Subject to Remediation
SiteLocation
Upland Area
Upland Area
KArea
Fire Pond
South Ponds
Hershey Run
Media
Surficial soil
Subsurface soil
Soil
Sediment
Sediment
Sediment
EstimatedVolume (cy)
40,000
82,000
100
3,500
4,000
100,000
2.5 General Response Actions
GRAs are typically described as those general categories of actions that could be taken to satisfy the RAOs. Such
actions are generally identified based upon review and consideration of action-specific ARARs and remedial actions
used or considered for use at similar sites (USEPA, 1988). GRAs do not specify processes or materials to be utilized
for remediation, but rather identify generic technology types that could potentially be used for each environmental
medium under consideration. The potential feasibility of these broad technology types and their associated specific
process options are then preliminarily evaluated and screened in Section 3 of this FS against implementability,
effectiveness, and cost criteria. The following typical categories of response actions are briefly described and then
reorganized by media type into more specific GRAs that could be applied at this Site:
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• No Action. No remedial activities would be considered under this response action, but consideration of the
no action alternative is required by CERCLA and provides a baseline for comparison with other alternatives.
• Monitoring with Institutional Controls. This category generally includes activities such as access/deed
restrictions, consumption advisories, and monitoring that could be put in place to reduce current or future
exposure to constituents of concern. This category also includes assessment and/or monitoring of natural
attenuation processes (e.g., sedimentation and biodegradation) ongoing within Site media that can reduce
exposure over time.
• In-Place Containment. Sediment or soil capping are technologies that can be applied to contain materials
in-situ and therefore reduce potential exposure or migration. For sediments in riverine environments,
containment may take the form of hydraulic modifications such as rechannelization or relocation of the
channel and natural sedimentation to isolate chemicals and reduce the potential for future exposure.
• Treatment. A variety of ex-situ or in-situ technologies could be applied to reduce constituent levels or
mitigate migration. In groundwater, natural biological or chemical degradation processes may be enhanced
through the addition of nutrients or other additions to promote degradation and accelerate natural attenuation.
Removal and disposal technologies for sediments and soils include dredging or excavation followed by
subsequent management such as dewatering and appropriate disposal.
In consideration of the potential applicability of these GRAs to the three Site media (sediment, soil, and groundwater),
the following specific GRAs were assigned to each medium to address the associated RAOs:
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RAOs GRAs
Sediment
• Reduce potential unacceptable risks to the
structure and function of the benthic
macroinvertebrate community
• Minimize disturbance to the existing wetland
plant community
e \ e«_v — -^
• No Action
• Monitoring with Institutional Controls
• Hydraulic Modifications
(e.g., rechannelization or relocation)•* .
• In-Place Containment 7 *-^ «~r*~«r . \>Uv
• Ex-Situ Treatment (with on-site disposal or off-
site treatment)
Soil ^f cV.-^4* •
• Reduce the spatial extent of weathered NAPL
(physically disturbed) areas located at or near the
soil surface
• Minimize disturbance to the existing terrestrial\ P-plant community , o*-'1" •Jl>- v/*Ve' °r ' 1 C-\C+ — •>— {> • • '
• Prevent the future exposure of industrial workers
to soil with potential unacceptable risk
• No Action
• Monitoring with Institutional Controls ? ^
• In-Place Containment ( c-(7.
• Ex-Situ Treatment (with on-site disposal or off-
site treatment)
Groundwater
• Prevent the future exposure of human receptors toi i
groundwater containing NAPL
£ " V ^— <_v '
• No Action
• Monitored Natural Attenuation
• Recovery of Subsurface NAPL
(i.e., pilot study in wells MW-2A and MW-8A)
• Recovery and Treatment
~~\' /
*
i ..
v.W.U^
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3. Development and Screening of Remedial
Alternative Components
3.1 Overview
Section 2 of this FS identified several RAOs for the Site, the areas and media to be addressed, and a series of GRAs
that may be taken to remediate the Site. Each GRA is associated with one to several potentially applicable technology
types and process options. According to USEPA guidance (USEPA, 1988), the term "technology types" refers to
general categories of technologies such as institutional controls or capping. The term "technology process options"
refers to specific processes within each technology type. For example, the institutional control technology type would
include process options such as access and deed restrictions and monitoring. For each GRA identified, a series of
technology types and associated process options are assembled.
Following assembly of remedial technologies and process options, the remedial technologies are screened to eliminate
those that are not technically implementable. Specifically, those not retained for further consideration include
technologies and process options that have not been demonstrated to be technically implementable or not proven
effective in remediating a given medium (i.e., sediment, soil, or groundwater) at full scale. Following remedial
technology screening, process options are then screened to select one or more representative option(s) for each
implementable remedial technology. These selected process options are assembled into potential remedial alternatives
carried through to the subsequent detailed evaluation of alternatives in Section 4.
3.2 Identification of Remedial Technologies and Process Options
Based upon the site-specific GRAs developed in Section 2.5, several potential remedial technology types have been
compiled. Since a technology type is a general category, it may contain one or more specific process options. Tables
3-1A, 3-1B, and 3-1C provide lists of both established and innovative technologies and process options that are
potentially applicable to sediment, soil, and groundwater, respectively. In preparing Tables 3-1 A, 3-IB, and 3-1C,
reference was made to several sources of information, including Remediation Technologies Screening Matrix and
Reference Guide (DOD, 1994), Evaluation of Technologies for In-Situ Cleanup ofDNAPL Contaminated Sites
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(Grubb and Sitar, 1994), and Best Demonstrated Available Technology (BDAT) Background Document for Wood
Preserving Wastes: F032, F034, andFOSS; Final (USEPA, 1996).
The technology types and process options listed in Tables 3-1 A, 3-IB, and 3-1C were screened on the basis of
implementability at the Site as discussed above. Implementability is a general, nondetailed criterion for whether a
technology type or process option is applicable with respect to specific site conditions, and whether the technology
has been fully developed for use. Where appropriate, the administrative aspects of implementability, such as
regulatory agency approvals, are also considered. In addition, promulgated regulations, such as the prohibition from
land disposal of certain listed hazardous wastes that contain creosote (F034 designation; see 40 CFR 268), are also
considered in the screening of technology types. The screening was also based on technical implementability derived
from general knowledge and experience, BBL's accrued experience at similar sites, professional judgment, and the
literature.
The retained technologies and a minimum of one process option for each (Tables 3-1 A, 3-IB, and 3-1C) were
incorporated individually, or in combination, into a set of potential remedial alternatives for detailed analysis and
comparison. The basis for selecting certain remedial technologies and associated process options and eliminating
others is discussed below. The no-action GRA was included for use as a baseline against which other remedial
alternatives are evaluated. This approach is consistent with state and federal guidance and is required by the NCP.
3.3 Screening of Remedial Technologies and Process Options
3.3.1 Sediment Technologies
Remedial technology types that have been identified to address sediments include: 1) No Action, 2) Monitoring with
Institutional Controls, 3) In-Place Containment, and 4) Ex-Situ Treatment.
3.3.1.1 No Action
The No Action GRA for sediments provides a baseline for comparing other sediment technologies and process
options. This approach assumes that no additional remedial activities would occur beyond the existing Site
conditions.
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Effectiveness
Based on the results of the RI, this process option would be effective in the continued natural encapsulation of the
limited areas where NAPL is present in surface sediments within Hershey Run. With depositional rates of between
0.12 and 0.36 in/yr, newly depositing sediments will continue to naturally encapsulate the surficial NAPL areas,
further isolating this material from exposure to potential receptors. The low-energy environment along with the
significant vegetative cover will also continue to minimize the physical impact that any storm events may have on
depositional areas.
For sediments within the Fire and South Ponds, natural encapsulation would not be as effective due to the anticipated
lower rates of deposition within these ponds. As a result, the natural encapsulation of the surficial sediment NAPL
will take longer to isolate from the environment in comparison to the Hershey Run area.
Implementability
This process option would be technically implementable because no further remedial action would be taken.
Cost
This process option would have no costs.
Summary
NAPL present in surficial sediments would continue to be isolated from the environment in Hershey Run (and other
areas) due to natural encapsulation. To a lesser extent, surficial NAPL within the Fire and South Ponds would also
be reduced. In addition, the Site would continue to have access restrictions as well as the posting of notices along
property lines. In accordance with USEPA guidance (USEPA, 1998), this process option will be retained for further
evaluation.
3.3.1.2 Monitoring with Institutional Controls
The monitoring with institutional controls GRA for sediments would likely include periodic land use restrictions, and
continued access restrictions with appropriate signage. Access to the site is already extremely limited due to the
AmTrak rail lines, the Ciba-Geigy facility, and the remainder of the Site bounded by various waterways.
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Effectiveness
Through monitoring, land use restrictions, and access restrictions, this process option would reduce or eliminate
potential human exposures to surficial sediments at the Site and would therefore be effective. As previously
discussed, natural recovery processes would be effective over time in isolating sediments in place and reducing
potential ecological exposure.
Implementability
This process option would be technically implementable, since it would require minimal activities.
Cost
Since this process option would require minimal activities, it would have relatively low capital and O&M costs.
Summary
Potential human and ecological exposure to NAPL in certain surface sediments would continue to be reduced or
eliminated (and monitored) through continued natural encapsulation in depositional areas. Human access to these
areas would continue to be restricted through institutional controls. For these reasons, it is appropriate to retain
monitoring with institutional controls for further evaluation.
3.3.1.3 In-Place Containment
In-place containment is a type of remedial technology in which sediments are covered with one or more layers of
clean capping material. Typically, this clean material is imported from an off-site source (usually a nearby quarry)
or obtained from an on-site source. Capping and hydraulic modification are the process options that have been
selected for screening under this technology type.
For the capping process option, capping materials such as sand or soil are distributed across the targeted sediment
surface within the waterway or pond. The capping material is usually discharged above the existing sediment surface
where it is allowed to "broadcast down" over the area to be capped. Physical measurements of the thickness of the
deposited material would be performed to determine the appropriate cap thickness. This process option could be used
in combination with other process options such as dredging or hydraulic modification based upon the unique physical
characteristics of the waterway. For example, sediments could be capped in areas of relatively low energy or those
areas where dredging equipment could not effectively operate.
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Capping materials are typically mechanically broadcast overthe edge of a barge or by some other similar construction
methodology. Capping materials typically selected are larger-grain sized materials that have a limited ability to erode
in comparison to finer-grained materials such as clays and silts. For this Site, the primary mechanism for erosion of
capping materials or sediment would be increased surface water velocities due to storm events. However, the low-
energy depositional ponds and marshes would not be expected to be disrupted, and vegetative cover would further
limit the potential effects of storm events.
For the hydraulic modification process option, Hershey Run could be rechannelized to avoid sediment NAPL areas
identified within the streambed. This rechannelization effort would require the construction of an alternative flow
path to divert flow around the sediment NAPL areas to White Clay Creek. After flow has been redirected, the former
streambed could be backfilled using either excavated materials, general fill, or both.
Effectiveness
Construction of sediment caps has been performed at several locations and has been found effective in isolating
sediment and enhancing intertidal habitat (Sumeri, 1996). Monitoring of the water column above existing capped
sediments and analysis of sediment/cap core samples would be needed to demonstrate that the caps are effective in
isolating contaminants from the environment.
Hydraulic modification would be effective in the isolation of sediment within Hershey Run through rechannelization.
Surface water would be permanently redirected from the vicinity of the Fire Pond to the confluence with White Clay
Creek, to a newly constructed waterway. This new waterway would be designed to be hydraulically similar to the
existing waterway to facilitate re-establishment of an equivalent channel and wetland environment. The existing
waterway would then be backfilled to permanently hydraulically isolate sediments in place and prevent potential
exposure.
Implementability
The capping process option, while challenging, would be technically implementable as demonstrated by the
successful capping efforts at numerous other sites. Approximately 8 to 10 inches of sediments would be sufficient
to "seal the contaminated sediment from the overlying water column" based upon U.S. Army Corps of Engineers
studies (Gunnison et al., 1988). A similar capping thickness could be appropriate for Hershey Run and upland water
bodies (e.g., Fire Pond, South Ponds), with a focused effort on those sediment areas where NAPL is present within
surficial sediments.
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In the event existing sediments have low bearing capacity and are unable to support the proposed 8 to 10 inches of
capping material, a geotextile cover would be placed over the existing sediment areas to provide the necessary
structural support for the cap. In general, implementation of a capping option would be complicated due to issues
associated with extensive access roads, potential impacts to archaeological sites, and access through the Ciba-Geigy
facility. Implementability would also be impacted by the size of the area and volume of capping material needed to
effectively cap an area. Larger areas and volumes would substantially complicate the construction effort with smaller
capping efforts being more implementable.
Hydraulic modification of Hershey Run via a new channel, while technically challenging, would be implementable
to isolate existing sediments from the water column. Under this GRA, the existing Hershey Run channel would be
filled with existing on-site material and the existing surface water diverted to a new channel constructed parallel to
the existing waterway. The construction effort would involve the excavation of approximately one mile of new
streambed and the backfilling of the former waterway. The previous Hershey Run channel would be allowed to
naturally revegetate with wetland plant species. The existing sediments would be capped beneath the relocated fill
material. This physical isolation from the environment would significantly reduce any potential exposure associated
with these sediments.
Cost
The capital and O&M costs associated with capping would be significantly higher allowing natural encapsulation
processes to continue decreasing exposure potential. Hydraulic modification, due to the construction of a new
channel and the backfilling of the former waterway, would have a higher cost in comparison to the capping.
Summary
There is documentation that in-situ capping and hydraulic isolation of sediment after rechannelization are proven and
reliable, methods for isolating sediments from the aqueous environment. As a result, these technologies will be
retained for the detailed analysis of remedial alternatives in Section 4.
3.3.1.4 Ex-Situ Treatment
For the purpose of this evaluation, sediment removal efforts were categorized into two general technologies:
mechanical removal and hydraulic dredging. These two general sediment removal technologies are evaluated below.
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Once removed, sediment would either be treated via incineration/thermal desorption or disposed of on site in an
appropriately permitted landfill constructed in one portion of the Upland Area.
Effectiveness
The removal of sediments is an extremely difficult undertaking due to the unique physical characteristics associated
with Hershey Run, and other waterways. Typically, a removal effort can be accomplished by one or a combination
of removal techniques: mechanical excavation (i.e., backhoe-like equipment) and or hydraulic dredging. However,
the physical limitations of Hershey Run, and marsh areas, with their shallow depths and poor-bearing-capacity soils,
make it technically infeasible to access this Site with large construction equipment of sufficient capacity to remove
sediments within a reasonable timeframe. Furthermore, while the shallow depths restrict dredging equipment access,
mechanical excavation or hydraulic dredge equipment is equally impeded due to the water depth of only a few feet.
This water depth prohibits the use of barge-mounted mechanical excavation equipment or hydraulic dredges, and may
therefore require diversionary structures or the complete isolation of sediments through the use of sheeting or some
other similar technique.
Based on these considerations and those summarized below, the removal of sediments is not expected to be effective
at this Site.
• Large sediment volume and depth - With the potential excavated sediment volume in Hershey Run of over
100,000 cy, the magnitude of such a massive removal effort would be relatively unprecedented for similar sites.
The depth of NAPL in some areas would also severely complicate the removal effort.
• Increase potential for sediment resuspension - Any removal effort would result in the resuspension of sediments
into the water column where water currents could transport these sediments downstream. While it is possible
to minimize suspended materials through silt curtains, increasing pumping capacity at the dredging head and
other engineering controls, even with these precautions a certain percentage of NAPL-containing sediments
would be released downstream and be deposited on the existing relatively clean surficial sediments.
• Equipment limitations - The U.S. Army Corp of Engineers has stated that "no existing dredge type is capable of
dredging a thin surficial layer of contaminated material without leaving behind a portion of that layer and/or
mixing a portion of the surficial layer with underlying clean sediment" (Palermo, 1991). Dredging at this Site
would remove the relatively clean surficial sediments which have been deposited over the deeper, higher
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concentration sediments. Specifically, as a result of the inherent sediment mixing process which occurs during
any dredging effort, residual sediments will have a higher average constituent concentration than the original
sediment surface following dredging.
From a sediment disposal perspective, thermal treatment (thermal oxidation or incineration) and on-site consol idation,
while difficult to implement, offer effective disposal options. However, thermal treatment will have high energy
requirements and if performed off site would require the off-site transport of potentially over 100,000 cy of sediments.
In addition to the sediment, a potentially combustible bulking agent (e.g., sawdust) would be necessary to reduce the
water content of the sediment to facilitate transport. The combined volume of sediments and bulking agents would
result in potentially over 20,000 truck round-trips through the Ciba-Giegy property.
On-site disposal of sediments within an on-site landfill, while difficult to implement, would be effective. The volume
of the landfill and thus the surface area would vary depending on the volume of sediments to be disposed. Bulking
agents would likely be necessary to facilitate the disposal of sediments within the landfill.
Implementability
As discussed in this section, the water depth of Hershey Run and marsh areas significantly impedes the
implementation of either dredging or mechanical excavation of sediments. Excavation within the various ponds
would be achieved through dewatering the ponds before commencing with the excavation effort. Implementation
of the thermal treatment process option is significantly more difficult than on-site disposal due to the technical and
administrative constraints of thermal treatment processes and the number of trucks required to transport the sediments
to the nearest incineration facility (800 miles away) in Calvert City, Kentucky.
Cost
The cost associated with sediment removal, treatment, and disposal is extremely high in comparison to other GRAs.
On-site disposal options are more cost-effective than off-site disposal due to the cost of transportation to the
incineration facility. However, on-site disposal costs are sensitive to material volumes making low to moderate
volumes more implementable and thus having a lower cost than large volumes (> 100,000 cy).
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Summary
Based on the above considerations, sediment removal, treatment, and disposal technologies are not effective or
implementable for large sediment volumes, and have very high potential remedial costs, but will be retained for
comparative purposes for the detailed analysis of remedial alternative in Section 4.
3.3.2 Soil Technologies
The technology types that have been identified to address on-site soils are:
1) No Action
2) Monitoring with Institutional Controls
3) In-situ Containment
4) Ex-situ Treatment
These GRAs are evaluated for their effectiveness, implementability, and cost below:
3.3.2.1 No Action
The No Action GRA for addressing soils at the Site provides a baseline for comparing other soil technologies and
process options. This approach assumes that no additional remedial activities would occur beyond the existing Site
conditions.
Effectiveness
As discussed in the RI and Sections 1 and 2 of this FS, the horizontal and vertical migration of subsurface NAPL
zones is restricted by the geologic characteristics of the subsurface, the low permeability of subsurface materials
(i.e.,clay units), the physical and chemical characteristics of NAPL, and the limited NAPL mass to cause migration.
In addition, there is no current exposure pathway for subsurface soils, and dissolved constituents are being naturally
attenuated near potential source areas. For these reasons, the No Action GRA would be effective except under a
future hypothetical scenario involving disturbance of subsurface NAPL-containing soils or withdrawal of associated
groundwater, as described in the HHRA.
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The No Action GRA for surface soils would be less effective. Weathered NAPL deposits at the soil surface in the
upland areas would remain in place and pose potentially unacceptable risks, to the extent exposure were to occur.
However, the deposits are weathered, dry, and immobile, and natural recovery processes would be expected to slowly
reduce potential exposure over time.
Implementability
Technically, this option would be implementable since no actions would be performed.
Cost
The no action process option would have no costs.
Summary
The No Action process option for soils will be retained for the detailed analysis of remedial alternatives in Section
4, as required by USEPA guidance (USEPA, 1988).
3.3.2.2 Monitoring with Institutional Controls
The monitoring with institutional controls GRA with regard to soils would include periodic visual inspections of
surface soils, use restrictions (constraints placed on future use of the Site to prevent future exposure to subsurface
soil), and continued access restrictions (constraints placed on access) to the Site. Access to the Site is restricted
through the use of 24-hour security-guarded gates at the Ciba-Geigy facility, fencing, and posting. Natural barriers,
such as the Christina River, White Clay Creek, and Hershey Run and the surrounding marshes also restrict access
along with the high speed AmTrak rail line to the north. Use restrictions would also be placed such that unauthorized
site work and/or the unauthorized construction of buildings or other Site developments would be restricted. An
appropriate monitoring program would be developed during the Remedial Design phase.
Effectiveness
Through monitoring, use restrictions, and access restrictions, this GRA would reduce potential (current or future)
exposures to NAPL-containing soils at the Site, and thus be effective. Access restrictions would have to be closely
coordinated in the future with any potential brownfields redevelopment efforts in the upland areas.
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Implementability
This GRA would be technically implementable since it would require minimal activities beyond performance of
monitoring and institutional controls.
Cost
Since this GRA would require minimal activities, it would have relatively low capital and O&M costs.
Summary
Potential exposures to the NAPL-containing soils at the Site would be reduced or eliminated through the
implementation of use and continued access restrictions; however, future use of the Site may be limited based on
access restrictions and potential risks associated with hypothetical exposure scenarios. This GRA will be retained
for the detailed analysis of remedial alternatives in Section 4.
3.3.2.3 In-Situ Containment
There are two major considerations for establishing an appropriate in-situ (capping/covering) process option: 1)
proper selection of construction materials and design requirements, and 2) identification of areas to be
capped/covered. For the cap/cover material and design requirements, three options were evaluated: 1) a RCRA-
type composite cap, 2) low permeability cover (2 feet of clay), and 3) a surface cover system (e.g. asphalt, soil,
or other material). These options are evaluated for addressing surface soils as containment technology is not
appropriate or necessary for subsurface soils.
Effectiveness
For the containment GRA, consolidation, relocation, and capping of surficial soil NAPL deposits with either a cap,
low permeability clay cover, or a surface cover system are all equally effective in isolating NAPL from the
environment.
Implementability
Although each of the three cap/cover designs would be implementable from a technical and administrative
feasibility perspective, each would have a different construction effort.
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The composite cap construction activity would involve the placement of low-permeability soils along with the
placement of a geomembrane and a geotextile over the existing surficial soil NAPL deposits. At a minimum, the
areas would be covered by a geotextile to provide additional bearing capacity to support the significant weight of
the cap.
A low permeability clay cover, would consist of 2 feet of clay or silt, compacted to achieve a specified
permeability. In comparison to the composite cap, this cover system would require significantly less material
(about one half of the volume) and is composed of a single material. Geotextile would be provided over the areas
to provide additional bearing capacity.
A surface cover system, approximately 6 inches in thickness, could be constructed of a number of different
materials such as soil, gravel, asphalt, or some other material. Design of a surface cover system would be
influenced by future redevelopment of the Site. For example, a surface cover of asphalt may be the most
appropriate process option should a parking area be needed. A soil cover may be more appropriate in the event
future site development required a landscaped/lawn area.
Cost
The highest cost for the containment cap/cover process options would be associated with a composite cap.
Construction of a 2 foot clay or silt cap/cover would be less than the construction of a composite cap but more
costly than a surface cover system. Surface cover systems offer the lowest cost option due to the type of cover
system components.
Summary
All three containment cap/cover process options are effective in eliminating potential exposure through the
isolation of surficial soil weathered NAPL deposits from the environment. Both the composite cap and low
permeability cover options are more difficult to implement due to their more significant design and large volume
of capping/covering materials in comparison to the surface cover system process option. Due to the increased
construction effort, the cost for the composite cap and low permeability cover is higher than the surface cover
system. Based on these considerations, containment/capping options are retained for detailed analysis of remedial
alternatives in Section 4. However, because the distribution of NAPL deposits is in relatively small localized
volumes over a large area, capping of each individual deposit was determined to be impractical from a
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constructability perspective. The excavation and on-site consolidation (i.e., landfilling) of these areas may be more
effective than in-place capping.
3.3.2.4 Ex-Situ Treatment
The ex-situ process options evaluated for potentially addressing surficial soil weathered NAPL deposits are: 1.
thermal treatment (incineration/thermal desorbers), and 2) on-site consolidation/disposal. Ex-situ treatment options
for subsurface NAPL-containing soils are not evaluated because of the technical impracticability of NAPL recovery
from immobile NAPL zones. The rationale for this determination is provided in the next section (Section 3.3.3),
which discusses the impracticability of removing subsurface NAPL zones. However, the natural attenuation of
groundwater is discussed, as is a potential pilot program to attempt recovery of NAPL observed in monitoring wells
MW-2A and MW-8A.
The first process option is the thermal treatment of surficial soil NAPL materials excavated from the upland areas.
Incineration is a method by which constituents are destroyed by heat, usually at temperatures between 1,600°F to
2,200°F. Similarly, thermal desorbers typically operate using similar processes as incinerators; however, they
typically operate at lower temperatures than incinerators and thus the treated media is typically not physically
altered (i.e., converted to ash). Instead, the elevated temperatures serve to drive off the constituents of interest for
collection and treatment in a separate treatment process. Materials are typically fed into a main combustion unit
ensuring even heating of the materials. Before the materials can be treated, they usually must be processed by
crushing and/or screening. Thermal units are usually equipped with an afterburner to reach acceptable constituent
removal goals, a quench to cool the treated material, and an air pollution control system to remove particulates and
acid gasses. Residual materials would be disposed of off site.
The second process option is the on-site consolidation/disposal of surficial soil NAPL deposits from several
locations in the upland areas. The consolidation/disposal effort would involve the development of construction
access roads to various surficial NAPL deposits for the excavation of this material using commonly available
construction equipment, such as backhoes. Due to hauled distances exceeding 500 feet, it would be more
economical to transport excavated materials to the on-site landfill using dump trucks. Upon reaching the on-site
landfill, the materials would be unloaded from the dump trucks and compacted. Upon completion, the on-site
landfill would be capped/covered in accordance with applicable requirements.
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Effectiveness
The effectiveness of these process options would be high since materials would be removed from the surface of
the Site, which would eliminate exposure pathways.
Implementability
Ex-situ process options are implementable for the on-site consolidation/disposal or the off-site disposal of surficial
soils. However, the off-site treatment of soils is significantly more difficult to implement due to the more than
8,000 one-way truck loads of material (over 40,000 cy) that must pass through the Ciba-Geigy facility. This
construction effort would significantly impact the ongoing operation at the Ciba Geigy Plant. As a result, the on-
site consolidation/disposal of materials is significantly more implementable than the off-site thermal treatment of
materials.
Cost
Costs for excavation and on-site consolidation/disposal option are moderate. Excavation and off-site disposal
option costs would be significantly higher due to the cost of transportation and disposal.
Summary
Based on the above considerations, the on-site consolidation/disposal of surficial soil NAPL deposits to an on-site
location and off-site thermal treatment will be retained for the detailed analysis of remedial alternatives as discussed
in Section 4. Note that the remediation of subsurface soils and NAPL zones is considered technically impracticable,
as discussed in detail in Section 3.3.3.
3.3.3 Groundwater Technologies
3.3.3.1 Current Conditions and Appropriateness of a Tl Determination
PAHs and certain other CoPCs have been detected in groundwater under the former Process Area and are assumed
associated with the discrete subsurface NAPL zones located there (Figure 1-4). NAPL also has been observed in
monitoring wells MW-2A and MW-8A located in and near the Process Area. However, as discussed in the RI
report and in Section 1.3 of this FS (see also Appendix A), constituents in nearby groundwater are rapidly
attenuated with distance from these probable source areas so that CoPC concentrations significantly decrease or
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are not detected in monitoring wells beyond the former Process Area and at the perimeter of the Site. Moreover,
the subsurface NAPL zones are discontinuous, limited in areal extent, immobile, and confined to the Columbia
Formation soils (upper hydrostratigraphic unit). Subsurface boring logs and chemistry data from the RI support
the conclusion that subsurface NAPL zones are discontinuous and of limited areal extent (i.e., the 11 NAPL zones
total approximately 6.5 acres in surface area and contain an estimated 82,000 cy of NAPL-containing soil; see
Figure 1-4). Similarly, Site operating history, geologic characteristics, and the physical properties of the NAPL
material support the conclusion that subsurface NAPL is immobile and confined to discrete areas of the Columbia
Formation. For example, wood-treating operations ceased nearly three decades ago, yet subsurface NAPL zones
and creosote-NAPL-related constituents have not migrated beyond probable source areas below the former Process
Area. Lack of horizontal and vertical migration is primarily accounted for by: 1) the lack of any ongoing active
sources that could increase the mass and migration potential of NAPL pools, 2) the lack of sufficient entry pressure
to advance the material through the low permeability soils because the density of the creosote NAPL is only slightly
greater than water, and 3) the lack of preferential migration pathways because the continuous clay unit beneath the
Colombia Formation provides a very low permeability confining layer to prevent NAPL movement into the lower
hydrostratigraphic unit of the Potomac Formation (no CoPCs have been detected in the Potomac Formation).
These observations and conclusions have significant implications regarding the feasibility of remediating
subsurface NAPL zone soils and affected groundwater. No existing technology is capable of removing NAPL from
deep subsurface soils, as virtually all NAPL would need to be removed to effectively restore soils and groundwater
quality, and achieve identified ARARs for this Site. While certain emerging technologies may be able to remove
some mass, the technologies are not proven reliable or implementable at full scale, and pose unacceptable and
unnecessary human health risks. The uncertain benefits of attempting to remove NAPL zones or groundwater
would be more than offset by the fact that unacceptable potential short-term risks could be created for construction
workers exposed to subsurface soils if excavation were attempted, and the intrusive nature of unproven groundwater
remediation technologies could cause remobilization of the now stable NAPL and disrupt the active natural
attenuation evident at the Site. For example, technologies focusing on mass removal via solubility enhancement
would pose unacceptable exposure-based risk and could drive more constituent mass into low-permeability zones
through molecular diffusion. Similarly, groundwater technologies focusing on hydraulic removal via pumping with
or without reducing NAPL/water interfacial tension (e.g., adding surfactants, alcohols, etc.) would pose the
unacceptable risk of remobilizing NAPL in unpredictable directions and spread beyond current limited zones.
Based on experience at other sites, any in-situ technology would require construction of a large, complex, and
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costly infrastructure, including installation of an inordinate number of closely-spaced pumping, injection, treatment,
or recovery wells deep into the Columbia Formation. In addition, such as invasive approach could pose the
unacceptable risk of drilling through and around NAPL zones, which would change subsurface hydrodynamic
conditions, potentially remobilize NAPL, and unpredictably alter existing groundwater flowpaths and attenuation
mechanisms. Use of invasive technologies would also raise the spectre of penetrating the protective clay layer
beneath the Columbia Formation and thus creating undesirable preferential pathways into the unaffected aquifer
of the Potomac Formation.
USEPA, in its guidance on the technical impracticability of groundwater restoration (USEPA, 1993), recognizes
that "locating and remediating subsurface sources can be difficult," and "source removal and remediation may be
difficult even where source locations are known." In these situations, USEPA states that "the appropriate level of
effort for source removal and remediation must be evaluated on a site-specific basis, considering the degree of risk
reduction and any other potential benefits that would result from such an action." On balance, it appears that the
potential risks and adverse impacts posed by available or emerging technologies may far outweigh the limited and
uncertain benefits that each technology may provide.
Given these conditions, that is the stable and discontinuous NAPL zones and the lack of any effective remedial
technology for addressing NAPL in subsurface soils and groundwater, a technical impracticability determination
is considered appropriate and warranted for this Site. Such a Tl determination would recognize that recovery of
subsurface NAPL is likely to be ineffective and complete restoration or groundwater quality is not technically
possible from an engineering perspective. Nevertheless, RI data do indicate that natural attenuation processes are
active at the Site (Appendix A) and groundwater impacts do not extend far beyond known NAPL zones, which
means that a remedy based on a Tl waiver of applicable groundwater ARARs and coupled with monitored natural
attenuation and appropriate institutional controls (e.g., restrictions on future use of groundwater for potable uses)
will achieve applicable soil and groundwater RAOs and provide acceptable overall protectiveness of human health
and the environment.
3.3.3.2 Tl Zone and Alternative Remedial Strategy
USEPA's (1993) Tl guidance and its guidance on the use of monitored natural attenuation for groundwater
restoration (USEPA, 1997c) require that a Tl Zone be determined to focus further regulatory action and, because
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removal or other means of treatment are impracticable (and likely ineffective as well), that an alternative remedial
strategy be developed to achieve RAOs and provide adequate overall protectiveness as required by the NCP.
Alternative RAOs may also be defined, if necessary and appropriate. The guidance also requires that a full Tl
evaluation be conducted to carefully define the Tl Zone and associated regulatory aqueous plume, and develop an
alternative remedial strategy to: 1) control exposure, 2) control sources, and 3) remediate the aqueous plume to the
extent practicable. Although a comprehensive Tl evaluation is not provided as part of this FS, for purposes of
development and evaluation of remedial alternatives the Tl Zone and alternative remedial strategy are preliminarily
discussed below.
The Tl Zone is the spatial area of the Site over which the Tl determination would apply and ARAR waivers would
be granted. The proposed Tl Zone and its rationale would be quantitatively defined in detail in the Tl evaluation,
but for purposes of this FS the zone is qualitatively estimated to encompass three subsurface zones: 1) the
subsurface NAPL zones already defined for the Site (see Figure 1-4), likely to be focused only on the two or three
zones associated with the former Process Area and also associated with detections of CoPCs in groundwater at
levels that may pose unacceptable risks, 2) the matrix diffusion zone or zones that may be extending into soils
beyond the discrete NAPL zones, and 3) a potential aqueous plume extending beyond the matrix diffusion zone.
Based on RI data (i.e., lack of CoPC detections downgradient of NAPL zones) and the preliminary natural
attenuation evaluation provided in Appendix A, the matrix diffusion zone and aqueous plume are not expected to
extend any appreciable distance away from NAPL zones because of the attenuation processes that are significantly
limiting NAPL impacts on Site groundwater. Because RI data support the conclusion that groundwater impacts
are severely limited in areal extent away from known NAPL zones, the Tl Zone is preliminarily assumed to be a
discontinuous zone that collectively encompasses the 11 discrete subsurface NAPL zones shown on Figure 1-4.
These NAPL zones range in areal extent from approximately 2,400 square feet to 69,600 square feet, totaling
approximately 6.5 acres. This is a reasonable first estimate of the extent of the Tl Zone given that only the larger
areas near the Process Area and containing unacceptable levels of CoPCs are expected to be included in the Tl
determination, but the Tl Zone would include the relatively small aqueous plumes expected to be present
immediately surrounding or downgradient from those larger NAPL zones.
In accordance with the requirements for a Tl determination and waiver of ARARs, an alternative remedial strategy
must be developed to consider what measures are feasible (i.e., effective, implementable, cost-effective) for
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mitigating potential exposure and providing overall protectiveness despite the fact that unrecoverable NAPL
materials will remain in the subsurface. Development of such a strategy begins with an evaluation of the restoration
potential of the Tl Zone, which in addition to preparation of cost estimates, is required to include the following
analyses (several Tl guidance requirements are quoted below, in italic typeface, followed by a response hat would
be fully developed in the Tl evaluation):
1. "A demonstration that contamination sources have been identified and have been, or will be, removed and
contained to the extent practicable. " The RI identified the spatial extent of NAPL zones within the subsurface
soils and established that the NAPL deposits are not mobile, which suggests that intervention to remove,
contain, or control the zones is unnecessary and, in any case, technically impracticable. Further, there is no
continuing source of NAPL to the subsurface given that active use of wood-treating materials at the Site ceased
nearly 30 years ago and remaining surficial soil NAPL deposits are thoroughly dried, weathered, and immobile.
2. "An analysis of the performance of any ongoing or completed remedial actions. " Given that a "front end" Tl
determination is sought prior to the start of remedial actions at the Site, this requirement would be addressed
through a detailed discussion in the planned Tl evaluation of what long-term monitoring would be necessary
to document NAPL immobility, ongoing natural attenuation within the designated Tl zone, and the
effectiveness of other remedial actions that may be selected for the Site. The Tl evaluation could also assess
(i.e., predict) the potential benefits of alternative remedial actions such as remediation of surficial soil NAPL
deposits, if such actions were likely to be selected as part of an overall Site remedy.
3. "Predictive analyses of the time frames to attain required cleanup levels using available technologies. " The
natural attenuation evaluation developed during the RI concluded that even after decades of time, constituents
in groundwater remain confined to the upper hydrostratigraphic unit, have not migrated off site or into
monitoring wells any appreciable distance from likely source areas (i.e., the subsurface NAPL zones), and in
fact, are rapidly naturally attenuating just beyond the NAPL zones.
4. "A demonstration that no other remedial technologies (conventional or innovative) could reliably, logically,
or feasibly attain the cleanup levels at the site within a reasonable timeframe. " USEPA acknowledges that
proven reliable and effective removal technologies do not exist for recovery of large subsurface masses of
NAPL. Moreover, for restoration efforts to be successful the entire potential NAPL zones would have to be
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remediated, which is technically impracticable to accomplish. However, a NAPL recovery pilot study (e.g.,
attempt recovery through wells MW-2A and MW-8A) could be conducted to evaluate the feasibility of
pursuing further removal of potentially mobile NAPL in these two wells.
These and other lines of evidence and justification to be developed in the Tl evaluation support the conclusion that
removal of subsurface soil or the pumping and treating of NAPL and affected groundwater are impracticable and
that emphasis should instead be placed on developing an alternative remedial strategy that relies on monitored
natural attenuation of groundwater and appropriate institutional controls to limit the potential for future exposure
to subsurface NAPL or groundwater, thereby achieving the RAOs. However, because NAPL was found pooled
in two on-site monitoring wells (MW-2A and MW-8A), recovery of NAPL within those wells will be attempted
via a pilot study effort. Taken together, and briefly described below, these elements of an alternative remedial
strategy will sufficiently address the three objectives of such remedies as stated in USEPA's Tl guidance (i.e.,
exposure control, source control, aqueous plume remediation), and be protective of human health and the
environment.
Exposure Control - The alternative remedial strategy will meet this objective by providing institutional controls
for the purpose of preventing human exposure to subsurface soils and groundwater, which were potential future
exposure pathways identified in the HHRA. Restrictions placed on subsurface excavations in identified zones and
placed on the future use of Site groundwater for potable uses would be effective at preventing exposure. In addition
to being effective, these restrictions would be readily implementable as deed restrictions or other administrative
controls, and would be low cost and cost-effective. Coupled with restrictions on land use that would ensure that
the Site remains in industrial use if redeveloped or sold, these exposure control provisions would satisfy the
applicable RAOs for this Site and would provide the overall protectiveness required by the NCP.
Source Control - The key findings of the RI that pertain to this objective is that the data indicate: 1) the subsurface
NAPL zones are stable, immobile, and not increasing in mass, and 2) natural attenuation processes are actively
reducing CoPC levels in groundwater within short distances from subsurface NAPL zones. In addition to the
multiple lines of physical and chemical evidence supporting these findings, it is known that active sources of
creosote NAPL to the subsurface ceased nearly 30 years ago. In addition, the weathered NAPL deposits on surficial
soils, which are immobile and pose an unlikely source of CoPCs to subsurface soils or groundwater, represent an
opportunity for additional source control and exposure reduction at the Site and will be considered in assembling
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and evaluating remedial alternatives for the Site. Finally, a pilot study will be developed to attempt recovery of
the NAPL observed in wells MW-2A and MW-8A. The pilot study would involve the manual removal of NAPL
by bailing the two wells periodically and recording volume and rate of recovery. Based on a large body of similar
experience elsewhere, it is anticipated that a limited quantity of NAPL will be recovered and disposed, and
quantities will decrease rapidly after initial efforts are complete. The method of recovery is expected to be
relatively effective on a pilot scale, but only for a short period and not if applied at a larger scale. The bailing
process is simple, which makes it readily implementable and low cost. Over extended periods or at larger scale
the recovery of NAPL from these wells would be expected to be much less feasible to implement and would not
be cost-effective for amount of effort versus volume recovered.
An important element of source control efforts is the need to prevent any actions that could remobilize the
subsurface NAPL away from existing zones. As described previously in Section 3.3.3.1, a Tl determination is
warranted at this Site in part because any intrusive measures into the subsurface may result in worsening conditions.
For example, attempts to excavate soils or develop a matrix of groundwater recovery or treatment wells could
change subsurface hydrodynamics (e.g., groundwater flowpaths), remobilize NAPL materials in unpredictable
directions, or penetrate the Potomac Formation clay layer and jeopardize the integrity of the lower aquifer. The
serious short- and long-term risks associated with these actions, and their expected limited effectiveness and
implementability, clearly support the conclusion that invasive technologies would provide few reliable benefits and
should be avoided. In other words, a greater level of source control, protectiveness, and exposure/risk reduction
will result from implementation of the monitored natural attenuation with institutional controls alternative remedial
strategy than any array of active technology.
Aqueous Plume Remediation - Restoration of affected groundwater within the Tl Zone is expected to be
impracticable within a reasonable timeframe, but Site characteristics and chemistry data indicate that the aqueous
plume will not increase with time and that natural attenuation is limiting the impacts posed by the presence of
historical NAPL in the subsurface. As described above, active remediation of groundwater is not technically
practicable, nor is it prudent, and current and anticipated future source and exposure controls are expected to be
effective in protecting human health and the environment over both the short and long term. Therefore, monitored
natural attenuation, institutional controls, and the NAPL recovery pilot study are expected to be effective in
reducing exposure and potential risk, are readily implementable, and are cost effective. Above all, this approach
to remediation will achieve RAOs and provide a reliable level of protectiveness of human health and the
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environment. The anticipated continued protectiveness and reliability of this approach would be verified over time
through the monitoring program that would need to be developed as an integral component of the remedy.
Summary - A protective remedial strategy would result from the above components when coupled with a Tl
determination that would waive applicable ARARs, establish the Tl Zone to be regulated, and provide a detailed
evaluation of the technical impracticability of remediating subsurface soil and groundwater. However, to complete
this FS in full compliance with USEPA (1988) guidance, the remainder of this subsection on screening groundwater
technologies will briefly review the effectiveness, implementability, and relative cost of the three GRAs established
for the Site in Section 2: no action, monitoring with institutional controls, and recovery and treatment. Components
of these technology types may be carried forward into the assembly and evaluation of remedial alternatives (Section
4), but the preceding discussion suggests that the components of the proposed alternative remedial strategy offer
the greatest degree of compliance with RAOs, screening criteria, and, by extension, the nine evaluation criteria
required by the NCP for detailed and comparative evaluation of remedial alternatives.
3.3.3.3 No Action
The No Action GRA with regards to groundwater at the Site provides the baseline for comparing other groundwater
technologies and process options. This approach assumes that no addition remedial activities would occur beyond
the existing Site conditions.
Effectiveness
The No Action process option is effective. Natural attenuation characteristics associated with the Site are favorable
for the continued degradation of CoPCs, as evidenced by the fact that constituents were not detected in monitoring
wells along the perimeter of the Site.
Implementability
Technically this option is implementable since no actions would be completed.
Cost
This process option would have no costs.
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Summary
The No Action process option is effective in addressing groundwater constituents. Natural attenuation is effectively
reducing constituent concentrations within close proximity of potential source areas. Since no actions are
occurring, the process action is implementable and the capital costs are $0. This process option will be retained
for detailed analysis of remedial alternatives in Section 4.
3.3.3.4 Monitored Natural Attenuation
The Monitored Natural Attenuation GRA with regard to groundwater would include the periodic monitoring of
groundwater concentrations immediately downgradient of potential source areas. Institutional controls, such as
deed restrictions, would be included to prevent the installation of drinking water supply wells on site and thus
minimize the potential for unacceptable exposure to groundwater. A component of the monitoring program would
involve the development of a monitored natural attenuation program to verify the extent that attenuation processes
are occurring and effective. This program would be developed in accordance with the applicable USEPA guidance
(USEPA, 1993; 1997c).
Effectiveness
Through deed restrictions this process option would reduce or eliminate possible exposure to Site groundwater and
thus be effective.
Implementability
This process option would be technically implementable since it would require minimal activities.
Cost
Since this process option would require minimal activities it would have a relatively low capital and O&M costs.
Summary
Potential exposure to Site groundwater would be reduced or eliminated through natural attenuation as well as
through deed restrictions. As a result, this process option will be retained for the detailed analysis of remedial
alternatives in Section 4.
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3.3.3.5 Groundwater Recovery and Treatment
This GRA would include the recovery of groundwater downgradient in the vicinity of the former Process Area
located in the upland area. For the purpose of developing this GRA as a process option, it is assumed that numerous
recovery wells would be installed to intercept groundwater within the upper aquifer. The collected groundwater
would then be pumped from this recovery well system for treatment at an on-site waste water treatment plant, with
the discharge being to either Hershey Run or the Christina River.
Effectiveness
As stated above, the various recovery wells would attempt to recover groundwater that contains CoPCs. While an
aquifer performance test has not been conducted, it has been estimated that the quantity of water recovered from
these wells could be significant due to the proximity of nearby waterways and subsurface hydrogeologic conditions.
In contrast, experience at other site suggest that recovery of NAPL or CoPCs would be very small, even after long
periods of operation.
Implementability
Installing a groundwater recovery system, treating the recovered groundwater, and discharging the treated
groundwater to an existing surface water body is difficult but technically implementable. As part of remedial
design, engineering calculations and treatability studies would be required to confirm the actual quantities of
groundwater which would be recovered. In addition, a treatment facility would have to be designed to achieve any
discharge permitting requirements established by the State of Delaware.
Cost
The capital and O&M costs associated with implementing the on-site treatment of recovered groundwater would
be high.
Summary
It is unlikely that this process option provides any additional benefits over natural attenuation. However, for
comparative purposes, this process option will be retained for the detailed analysis of remedial alternatives in
Section 4.
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3.4 Assembly of Potential Remedial Alternatives
Based on the evaluation of technology types and process options for the different media associated with the Site
(soils, sediment, and groundwater), the following process options were retained for assembly into remedial
alternatives (see also Table 3-1):
• No Action
• Monitoring with Institutional Controls
• Monitored Natural Attenuation
• In-Situ Technologies (containment/capping)
• Ex-Situ Technologies (removal, thermal treatment offsite, consolidation and landfilling on site)
These components were assembled into a series of remedial alternatives for detailed and comparative analysis in
Section 4. The five remedial alternatives are:
• Alternative 1 - No action;
• Alternative 2 - Monitored natural attenuation, institutional controls, and pilot study;
• Alternative 3 - Upland surface soil removal, upland sediment containment, on-site disposal,
monitored natural attenuation, institutional controls, and pilot study;
• Alternative 4 - Hershey Run rechannelization, upland surface soil and sediment removal, on-site
disposal, monitored natural attenuation, institutional controls, and pilot study; and
• Alternative 5 - Hershey Run sediment removal, upland surface soil and sediment removal, off-
site thermal treatment, groundwater recovery and treatment, monitoring,
institutional controls and pilot study.
In Section 4, these alternatives are evaluated in detail based on the nine NCP criteria.
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4. Detailed Evaluation of Remedial Alternatives
4.1 Overview
In accordance with the NCP, this section describes the detailed evaluation of potential remedial alternatives
developed for the Site. This detailed evaluation presents information relevant to the selection of a site remedy.
Each potential remedial alternative is assessed against a set of evaluation criteria that are described below. The
results of this evaluation of individual alternatives are then compared in Section 5 in terms of each criterion and
key tradeoffs among the various alternatives.
The detailed evaluation of potential remedial alternatives developed for the Site is presented below. A description
of each alternative is followed by an assessment of potential environmental effects and post-remedial risk (see also
Tables 4-1 through 4-5) and then by an evaluation relative to each individual NCP criterion. For purposes of this
FS, post-remedial risk is evaluated regarding the level of potential exposure and associated risks that may remain
after remedial activities are completed. The proposed equipment/processes that are described are subject to
modification during the design phase. Additionally, preliminary time frames that may have been noted also are
subject to additional refinement following the collection of detailed design information. Preliminary cost estimates
for each alternative have been developed and are provided in Tables 4-6 through 4-10.
4.2 CERCLA Evaluation Criteria
The NCP and CERCLA require that remedial alternatives be evaluated with respect to nine criteria in order to select
the most appropriate remedial alternative. The nine evaluation criteria are as follows:
1. Overall Protection of Human Health and the Environment - This criterion is used to address the overall
effectiveness of an alternative in protecting human health and the environment by reducing potential exposure
to achieve the identified RAOs.
2. Compliance with ARARs - This criterion is used to determine whether a given alternative would comply with
chemical-specific, location-specific, and action-specific ARARs as well as other criteria, advisories, and
guidance, as appropriate.
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3. Long-Term Effectiveness and Permanence - This criterion considers the effectiveness of a given alternative
with respect to reducing exposure and potential risk and the ability to maintain protectiveness over time.
4. Reduction of Toxicity, Mobility, or Volume Through Treatment - This criterion is used to consider expected
reductions in toxicity, mobility, or volume of chemical-containing materials as a result of implementing an
alternative.
5. Short-Term Effectiveness - This criterion considers short-term adverse impacts on human health and the
environment that would be due to construction and implementation of the remedial alternative. Considerations
include short-term environmental impacts of construction and the protection of on-site workers and the
neighboring community.
6. Implementability - The implementability of an alternative is evaluated based on its technical and
administrative feasibility, and the availability of appropriate services and materials. Technical feasibility
includes the ability to construct and operate the technology, the reliability of the technology, and the ability
to effectively monitor the technology. Administrative feasibility includes the ability to obtain any applicable
permits, and the degree to which any coordination with other government agencies can be achieved.
7. Cost - The cost criterion is used to evaluate capital, operation and maintenance (O&M), and present worth costs
of implementing an alternative. Present worth costs, where appropriate, are developed using a discount rate of
5 percent. In consideration of engineering and construction contingencies, these feasibility-level costs are
generally estimated with an accuracy in the range of+50 percent to -30 percent.
8. State Acceptance - This criterion is used to address the technical and administrative issues that the non-lead
regulatory agency (typically the state, in federal-lead projects) may have regarding each alternative. This
criterion is typically evaluated following comment on the RI/FS reports and the proposed plan. It will be
addressed once a final decision is being made and the Record of Decision (ROD) is being prepared.
9. Community Acceptance - The community acceptance criterion is used to evaluate any issues and concerns
that the public may have with the selected alternative following public comment on the proposed plan. It will
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be addressed once a final decision is being made and the Responsiveness Summary of the ROD is being
prepared.
4.3 Alternative 1 - No Action
Description
Alternative 1 would involve no active remediation or long-term management at the Site. However, ongoing natural
attenuation processes would continue to occur as evidenced by the presence of high retardation factors, geochemical
indicators, and observations of biodegradation of similar constituents reported in the literature (Appendix A).
Moreover, the physical and chemical characteristics of NAPL and certain geotechnical properties of Site soils (e.g.,
low permeability) restrict NAPL mobility and hence, potential migration. Constituents in groundwater are therefore
subject to natural attenuation processes during the long residence times over which groundwater travels through
the low-permeability soils at the Site.
Site constituents in sediment also are subject to natural attenuation, specifically sedimentation (burial) and
biodegradation processes. Estimated rates of net sediment deposition in Hershey Run and the West Central
Drainage Area were reported in the RI Report as being up to 0.36 and 0.25 inches per year, respectively. Similarly,
surface soil in runoff, and decaying vegetation are likely being deposited in low-lying areas such as the ponds and
marshes. Vegetative root growth also would serve to cover and restrict both the mobility of, and exposure to, Site
constituents at or near the surface. Although these processes may be active at the Site, the no-action alternative
would not include long-term monitoring to evaluate Site conditions, over time.
Assessment of Environmental Effects and Post-Remedial Risk
Remedial Alternative 1 proposes no active remediation at the Site. Therefore, there would be no mechanical or
engineering processes that could alter the ecological and cultural features of the Site, and no immediate change
would be expected in these characteristics from currently existing conditions (Table 4-1). Under this alternative,
potential risk associated with exposure to CoPCs in sediment would decline via natural recovery processes such
as sediment encapsulation and natural degradation of chemicals. Natural attenuation of groundwater would also
continue.
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The timeframe for sediment natural recovery to significantly decrease potential exposure to CoPCs is relatively
short (8.5 to 11.5 years) due to the rapid sediment deposition rates expected within drainage areas. As documented
in the RI Report (BBL 1999), estimated net deposition rates in Hershey Run and West Central Drainage Area are
0.36 and 0.25 in per year, respectively. Based on these deposition rates, a simple mathematical mixing model can
be used to evaluate the potential rate of natural recovery of the surficial sediment layer.
This model assumes that a uniform rate of net deposition occurs (i.e., more deposition than scour occurs), and there
is complete mixing of the sediment surface layer. Using a mixing depth of approximately 10 cm, the depth of
greatest biological activity (Karickoff and Morris 1985), it is estimated that the surficial sediment concentrations
will continue to decrease by half approximately every 8.5 to 11.5 years. Existing site conditions support this
depositional model, since the highest PAH concentrations located within the deeper sediments of Hershey Run and
West Central Drainage Area have been covered by more recently deposited cleaner material. In contrast to the
wetlands, it is unlikely that natural recovery processes will benefit areas in terrestrial parts of the Site at the same
rate, due to the limited depositional forces in these areas.
Overall Protection of Human Health and the Environment
The HHRA reported the potential for future human health risks to construction workers at the Site. While ongoing
natural attenuation processes at the Site will mitigate potential exposure over time, the absence of monitoring in
the no action alternative will preclude long-term evaluation of the effectiveness of these processes. As a result,
Alternative 1 does not provide a means to ensure that its implementation provides overall protection of the
environment or human health.
Compliance with ARARs
No chemical-specific ARARs have been identified for this alternative. Since no active remedial efforts would be
undertaken for this alternative, there are also no applicable action- and location-specific ARARs.
Long-term Effectiveness and Permanence
Long-term reduction in constituent concentrations in groundwater and surficial sediments would occur as a result
of natural attenuation and sedimentation processes, respectively. The immobility of NAPL in the environment
indicates that off-Site migration of these materials would be minimal and NAPL would remain confined to limited
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areas of the Site. Implementation of this alternative would not provide long-term effectiveness if land use at the
Site were to change.
Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative 1 provides for no active treatment of Site constituents. Thus, no significant reduction in potential
toxicity, mobility, or volume would occur through active treatment. Reductions in volume and potential toxicity
would likely occur through ongoing natural processes at the Site.
Short-term Effectiveness
Since no active remedial measures are to be performed as part of Alternative 1, there are no short-term adverse
impacts on human health and the environment due to its implementation. Also, there is no implementation time
associated with this alternative.
Implementability
This alternative poses no technical or administrative implementability concerns as no action would be taken. No
equipment or specialized services would be required to implement this alternative.
Cost
Since implementation of Alternative 1 does not involve any active remedial efforts, the present worth cost of this
alternative is $0 as also noted in Table 4-6.
4.4 Alternative 2 - Monitored Natural Attenuation, Institutional Controls, and Pilot Study
Description
Implementation of Alternative 2 would involve the same ongoing natural processes that were discussed in Section
4.3 for Alternative 1. However, Alternative 2 would also include:
• Monitored natural attenuation for groundwater and additional monitoring of other media;
• implementation of institutional controls; and
• a pilot study to evaluate the potential recovery of NAPL from wells MW-2A and MW-8A in the Process
Area.
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In Hershey Run and the West Central Drainage Area an appropriate level of monitoring would be conducted.
Representative samples would be collected and analyzed for CoPC to estimate potential changes in concentration
with time. Groundwater monitoring would be performed to confirm that constituents are not migrating from the
Site. It is anticipated that groundwater sampling would be performed at existing wells with a few (if any) additional
monitoring wells to be installed. The actual number and locations of any additional groundwater monitoring wells
would be determined during remedial design. The groundwater would also be monitored for natural attenuation
parameters to confirm that constituents continue to be naturally attenuated. The proposed monitoring frequency
would likely be quarterly the first year, semi-annually for the next two years and then annually thereafter.
The purpose of the monitoring program would be to demonstrate that natural attenuation is occurring as discussed
in the preliminary Natural Attenuation Assessment provided in Appendix A. Samples would be analyzed for site
constituents to show that these are not migrating, that there are no downgradient impacts, and that there are no new
releases to the environment. Additionally, changes in environmental conditions (e.g., hydrogeologic, geochemical
and microbiological) would be monitored. This would be monitored by collecting data that may include:
• electron acceptors such as dissolved oxygen (DO), sulfate, nitrate and ferric iron;
• electron donors such as total and dissolved organic carbon;
• nutrients such as orthophosphate and ammonia-nitrogen;
• metabolic byproducts such as dissolved nitrogen, carbon dioxide, methane, and ferrous iron and sulfide;
• cell mass through analysis for phospholipid fatty acids (PLFA); and
• groundwater quality parameters such as temperature, pH, conductivity, and oxidation-reduction potential.
Institutional controls that involve placement of warning signs, land use restrictions, and controlled access to the
property, also would be implemented. A deed restriction would be placed on the property that restricts its use to
industrial activity only, disallows the installation of drinking water wells, and prevents disturbance of subsurface
NAPL zones. Existing access restrictions to the property would continue indefinitely.
Wells MW-2A and MW-8A have shown evidence of NAPL that may be recoverable, and recovery from these wells
would be attempted as a pilot study over an appropriate period of time. Following bailing, the removed NAPL
would be containerized and transported off-site for treatment/disposal. These two wells represent a small portion
of the Site in the former plant area where potentially recoverable NAPL has been identified. At other wells at the
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Site, including those that are adjacent to wells MW-2A and MW-8A, potentially recoverable NAPL was not
observed. The NAPL recovery pilot study would be attempted over a period determined during Remedial Design,
and then the program would be re-evaluated in the future to determine whether it should be continued.
Assessment of Environmental Effects and Post-Remedial Risk
Remedial Alternative 2 includes a combination of monitoring and natural recovery for Hershey Run, West Central
Marsh, Fire Pond, South Ponds, and K Area; and natural recovery for the Upland Areas. Except for the pilot-study,
no active remediation is included in this alternative. Therefore, there would be no mechanical or engineering
processes that could alter the ecological and cultural features of the Site, and no immediate change from currently
existing conditions would be expected in these characteristics (Table 4-2). As with Alternative 1, potential risk
under this alternative will continue to decrease with time due to natural recovery processes in sediments. Periodic
monitoring of abiotic and biotic media, which is a component of this alternative, would help determine when
natural recovery is complete.
Overall Protection of Human Health and the Environment
As noted previously, the HHRA reported hypothetical future potential human health risks to construction workers
if exposed under some future use scenario. Ongoing natural attenuation processes at the Site will mitigate potential
exposure over time. This would be confirmed through appropriate monitoring under this alternative. Recovery
and treatment/disposal of recoverable NAPL in Wells MW-2A and MW-8A would be addressed through the pilot
study. Subsurface NAPL zones are technically impracticable to remove and would therefore remain in the
subsurface where they are not adversely affecting human health or the environment. As a result, Alternative 2
provides several means of providing overall protection of the environment and human health.
Compliance with ARARs
No chemical-specific ARARs have been identified for this alternative. Applicable action- and location-specific
ARARs would apply to potential installation of additional wells, monitoring and recovery/disposal of NAPL. These
ARARs would include provisions of the Resources Conservation and Recovery Act (RCRA), CERCLA, the
Occupational Safety and Health Act (OSHA), Department of Transportation (DOT) and Delaware transportation
requirements, and National Historical Preservation Act (NHPA). These ARARs can be complied with by meeting
the requirements of these statutes.
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Long-term Effectiveness and Permanence
As noted previously, long-term reduction in constituent concentrations in groundwater and exposure to surficial
sediments would occur as a result of natural attenuation and sedimentation processes, respectively. The physical
and chemical characteristics of NAPL and certain geotechnical property of Site soils (e.g., low permeability) restrict
NAPL mobility and hence, migration. The immobility of surficial and subsurface NAPL in the environment
indicates that off-site migration of these materials from the upland areas would not likely occur. As a result, NAPL
would remain confined to limited areas of the Site. Quantities of recoverable NAPL would be permanently reduced
through the pilot study. Implementation of this alternative would provide long-term effectiveness if land use were
to change (e.g., construction of drinking water wells or excavation) by the implementation of deed restrictions.
Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative 2 provides for limited removal and treatment of recoverable NAPL at the Site through the MW-2A and
MW-8A pilot study. This would result in reductions in potential toxicity, mobility, and volume through active
treatment. Reductions in volume and potential toxicity would also occur through ongoing natural processes at the
Site.
Short-term Effectiveness
Active remedial measures to be performed as part of Alternative 2 involves monitoring and the pilot-scale recovery
of NAPL from two wells. These NAPL recovery and monitoring efforts would be performed in accordance with
a project-specific Health and Safety Plan (HASP). Therefore, adverse short-term effects on human health and the
environment are not anticipated as a result of implementation of this alternative.
Implementability
This alternative poses no technical, or administrative implementability concerns. Monitoring equipment, NAPL
recovery pumps, containers and specialized services such as laboratory analysis would be required to implement
this alternative and are readily available. The purpose of the pilot study would be to evaluate the technical
implementability of such recovery efforts. In addition, pursuit of a Tl designation for subsurface NAPL and
associated groundwater impacts will require development of a Tl evaluation and approval of a Tl waiver.
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Cost
The estimated capital and operations and maintenance (O&M) costs to implement Alternative 2 are approximately
$103,000 and $153,000, respectively. This results in an overall estimated present worth cost of approximately
$2,410,000 over 30 years. Details on the estimated cost for implementing Alternative 2 are presented in Table 4-7.
4.5 Alternative 3 - Upland Surface Soil Removal, Upland Sediment Containment, On-site
Disposal, Monitored Natural Attenuation, Institutional Controls, and Pilot Study.
Description
Implementation of Alternative 3 would involve the same activities that were discussed in Section 4.4 for Alternative
2. However, in addition to natural attenuation for drainage area sediments and monitored natural attenuation for
groundwater, Alternative 3 would include:
• covering of materials in the Fire Pond, South Ponds, and K Area with soil;
• removal of weathered surficial soil NAPL deposits over areas of the Upland Area;
• construction and maintenance of an on-site landfill for disposal of surficial soil NAPL materials;
• evaluation of NAPL recovery through a pilot study at wells MW-2A and MW-8A; and
• implementation of appropriate institutional controls and long-term monitoring.
Under Alternative 3, the Fire Pond, South Ponds, K Area, and other portions of the Upland Area would be actively
remediated. Surficial NAPL deposits in the Process, Drip Track, Loading Dock, and Wood Storage Areas (an
estimate of approximately 40,000 cy based on RI data) would be excavated and disposed in an on-site facility.
Based on visual observation, surficial NAPL deposits would be excavated to depths where dry, weathered NAPL
and tar-like material are no longer observed, then transported to an on-site landfill. Excavated areas would be
backfilled with general fill, graded to facilitate surface drainage, and vegetated. Upon completion of excavation
and disposal activities, the on-site containment unit would be covered and closed in compliance with applicable
regulations. Long-term O&M activities would be implemented soon thereafter.
To eliminate potential ecological exposure within the Fire Pond and South Ponds, sediments would be capped in
place with a soil cover of approximately 1-foot thickness. The K Area would be covered with soil (i.e., filled with
approximately 3-4 feet of soil, plus a 6-inch layer of top soil, graded to facilitate surface drainage, and revegetated.
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As discussed for Alternative 2, this alternative relies on ongoing natural attenuation processes for Hershey Run and
other drainage areas. The ongoing natural processes will be monitored as noted previously and will include some
mechanism such as sediment traps to gauge ongoing deposition in Hershey Run. Groundwater restoration would
rely on monitored natural attenuation. A Tl designation would be sought based on the impracticability of
remediating NAPL zones in subsurface soils. As in Alternative 2, pilot-scale NAPL recovery would be attempted
at wells MW-2A and MW-8A in the Process Area.
Similar to Alternative 2, new institutional controls would be put in place to prevent future potable use of Site
groundwater or disturbance of subsurface NAPL zones, and existing access controls would remain in place.
Assessment of Environmental Effects and Post-Remedial Risk
Remedial Alternative 3 incorporates natural recovery of wetland marsh habitats, capping of the Fire Pond and South
Ponds, filling the K Area, and surficial soil excavation in the Upland Area. Because there is no active remediation
of marsh habitats under this alternative, there would be no immediate change in ecological or cultural
characteristics of these areas from currently existing conditions (Table 4-3). Potential exposure to ecological
receptors may persist in the upper reach of Hershey Run and at a few, small, disjunct areas of the West Central
Marsh (Figure 2-2) until potential exposure and CoPC concentrations in surficial sediment decline via natural
recovery processes.
Capping Fire Pond and South Ponds sediments with clean material would eliminate potential risk in these areas by
preventing exposure of ecological receptors to CoPCs in sediment. In addition, under this alternative, the habitat
diversity would be expected to increase as a result of the existing sediment being isolated from the environment
and by recolonization of the capped ponds with native plants and animals.
Excavation of surficial soil, weathered NAPL deposits in the Upland Area would eliminate potential risk in the
associated areas shown on Figure 2-2. The physical activities associated with removal actions would eliminate the
surrounding herbaceous cover, causing a temporary reversion to an early succession stage in the immediate area
surrounding the excavation area. However, the area will revegetate after remediation is complete. The Upland
Area has lower-quality habitat than wetland and wooded areas onsite because it has been the location of more
extensive and recent human activities, and has been invaded by exotic species.
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One potentially significant historic archeological site that lies within the Upland Area, the Wright Farm Complex,
may be affected depending on the extent of remediation activities (Kellogg and Catts, 1996). Additional
archaeological effects may occur depending on the extent and location of any potential future intrusive remedial
activities in the Upland Area.
Overall Protection of Human Health and the Environment
As noted previously, the HHRA reported hypothetical future potential human health risks to construction workers
if exposed under some future use scenario. Appropriate deed restrictions would prevent such future exposure
scenarios. Ongoing natural attenuation processes at the Site, together with covering or excavation and disposal of
surficial soil NAPL deposits, would eliminate or mitigate potential exposure pathways. Removal of recoverable
NAPL would be addressed through the pilot study and treatment/disposal. Subsurface NAPL zones are technically
impracticable to remove and would therefore remain in the subsurface where they are not adversely affecting
human health and the environment. Hence, implementation of Alternative 3 would significantly reduce potential
exposure and be protective of human health and the environment.
Compliance with ARARs
Similar to Alternative 2, there are no chemical-specific ARARs that have been identified for this alternative. The
applicable location-specific ARAR is the NHPA which can be complied with by avoiding, as much as possible,
areas designated as having archaeological value. For those sites where remedial activities may have an impact, a
Phase II Cultural Resources Survey would be necessary. Applicable action-specific ARARs can be complied with
and include RCRA, DOT, CERCLA, OSHA (federal) and the Delaware HSC and hazardous waste codes.
Long-term Effectiveness and Permanence
Implementation of Alternative 3 is expected to meet the RAOs for the Site and be effective over the long term.
Ongoing deposition of clean sediments in Hershey Run and other drainage areas would continue to further
encapsulate NAPL where present near the sediment surface. Similarly, soil cap/covers over the Fire Pond, South
Ponds, and K Area would prevent direct contact. Excavation and disposal of surficial soil NAPL deposits in the
Process, Drip Track, Loading Dock, and Wood Storage Areas would permanently remove this material. Backfilling
would prevent direct contact with any remaining residuals. The immobility of subsurface NAPL indicates that off-
site migration of these materials would be limited, and NAPL zones would remain confined to limited areas of the
Site subsurface. Quantities of recoverable NAPL would be permanently reduced through the pilot study. Ongoing
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natural processes would address constituents in groundwater. Monitoring would be used to confirm ongoing natural
attenuation and that the on-site containment unit is operating effectively over the long term.
Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative 3 provides for containment, removal, and treatment/disposal of recoverable NAPL and surficial NAPL.
This would result in significant reductions in mobility, volume, and potential toxicity through active treatment.
Reductions would also occur as a result of ongoing natural attenuation including degradation of Site constituents.
Short-term Effectiveness
Some potential short-term impacts to on-site workers may be associated with removal of material from the Upland
Area and construction or filling the on-site landfill. However, any particulate emissions would be addressed by
dust control technologies such as water or foam sprays. Potential exposures to on-site workers would be mitigated
through the use of personal protective equipment (PPE) and procedures detailed in a project-specific HASP.
Although there will be some increased traffic due to construction vehicles, the use of on-site containment/disposal
and the potential use of on-site backfill material would significantly reduce truck traffic off-site along local
community roadways that would arise from off-site disposal. Since this alternative does not include construction
activities in Hershey Run or other drainage areas, potential negative impacts on the wetlands and associated biota
are avoided.
Implementability
Materials and equipment necessary for the implementation of this alternative are readily available. This alternative
includes no intrusive work in the bordering marshes, and should therefore provide minimal implementability
challenges. Monitoring equipment, NAPL recovery pumps, containers and specialized services such as laboratory
analysis would be required to implement this alternative and are readily available. Implementation of the pilot
study would provide data with which to evaluate the technical implementability of recovery efforts. In addition,
pursuit of a Tl designation for subsurface NAPL zones and associated groundwater impacts will require
development and approval of a Tl evaluation and Tl waiver.
The presence of cultural artifacts of potential archaeological significance at the Site would be affected as a result
of excavation activities. Archeological sites that may be affected by these activities are the Worker Housing/Site
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7 area, the Lynam Farm Complex, prehistoric Site 3, and the Wright Farm Complex. Because of these potential
impacts, a Phase II Cultural Resources Survey would likely be necessary.
Cost
The estimated capital cost to implement Alternative 3 is approximately $5,484,000. The estimated annual cost of
O&M is approximately $198,000, resulting in a total present worth cost (over 30 years) of approximately
$8,490,000 to implement Alternative 3. Details on the estimated costs are presented in Table 4-8.
4.6 Alternative 4 - Hershey Run Rechannelization, Upland Surface Soil and Sediment
Removal, On-site Disposal, Monitored Natural Attenuation, Institutional Controls, and
Pilot Study.
Description
Implementation of Alternative 4 would involve:
• rechannelization of Hershey Run to a new location;
• removal of NAPL-containing sediment from the Fire Pond, South Ponds, and K Area;
• removal of surficial soil NAPL deposits from other upland areas;
• construction and maintenance of an on-site landfill for disposal of excavated materials;
• natural attenuation for groundwater and drainage area sediments;
• evaluation of NAPL recovery through a pilot study at wells MW-2A and MW-8A; and
• implementation of appropriate institutional controls and long-term monitoring.
Under Alternative 4, Hershey Run would be rechannelized such that surface water would no longer flow where
NAPL deposits have been identified in the Hershey Run Drainage Area. This effort would require the excavation
of an alternate flow path through the Hershey Run Drainage Area, followed by the redirection of flow from the
present Hershey Run to the reconstructed flow route. The new channel would be relocated to the west for the
northern reach and to the east of the existing channel for the southern reach. The course of the new channel would
be engineered to be an ecologically compatible and hydraulically functional conveyance through the existing tidal
environment, and also avoid NAPL-containing areas and any potential archaeologically significant areas.
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Specific channel dimensions and wetland habitat impacts would need to be determined following the collection of
additional Site-specific engineering data, most likely considered during Remedial Design. After flow has been
redirected, the former Hershey Run channel would be backfilled to the surrounding grade using either excavation
materials from the construction of the rechannelized stream, or general fill, or both. It is anticipated that this
component of Alternative 4 would be performed in dry-flow or low-flow conditions in order to minimize the
potential for soil erosion and the disruption to flow hydraulics. The new channel may be lined with rip rap (or other
material, as appropriate) to prevent erosion until new sediments have deposited and habitat conditions are similar
to the previous channel.
NAPL-containing soils in the Fire Pond, South Ponds, K Area, Process/Drip Track Areas, Loading Dock Area, and
Wood Storage Area would be excavated and disposed in an on-site landfill. Upon completion of excavation and
disposal activities, the containment unit would be covered and closed in compliance with applicable regulations.
Long-term O&M activities would be implemented thereafter. The Fire Pond, South Ponds, and K Area, would be
backfilled with soil and then graded to facilitate surface water drainage and revegetation. The other affected upland
areas also would be backfilled, graded, and vegetated.
As with both Alternatives 2 and 3, subsurface NAPL zones would be left in place since they cannot be actively
remediated on the basis of technical impracticability. However, NAPL recovery would be attempted during a pilot
study involving wells MW-2A and MW-8A in the Process Area, as discussed for Alternatives 2 and 3. Natural
attenuation processes and monitoring would be relied upon for groundwater and the West Central Drainage Area,
and deed restrictions and other institutional controls also would be implemented.
Assessment of Environmental Effects and Post-Remedial Risk
Remedial Alternative 4 incorporates rechannelization of Hershey Run; excavation and filling of the Fire Pond,
South Ponds, and K Area; and excavating surficial soil NAPL deposits in the Upland Area. The remedial
alternatives for all areas except Hershey Run and the excavation/filling of the ponds are essentially the same as in
Remedial Alternative 3; therefore, the assessment of environmental effects and post-remedial risk described in
Section 4.5 for these areas is also applicable under this alternative. Removal of sediment and soil in the Fire Pond,
South Ponds, and K Areas before filling, which is included in this alternative, would isolate sediments from the
environment by placing them in the on-site landfill and providing several feet of cover over the residual sediments.
In comparison to Alternative 3, this alternative would have an environmental effect due to the elimination of the
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Fire Pond rather than just capping the sediments to allow the pond to recover. The South Ponds would also be
eliminated but this would have a lower environmental effect because these ponds are ephemeral, subject to
desiccation at certain times of the year, and thus are of lesser environmental quality. Effects of the remedial
alternative on ecological and cultural characteristics of the Site are summarized in Table 4-4.
Re-channeling Hershey Run would not necessarily result in a loss of habitat, because material removed during
excavation could be used to backfill the existing channel and create tidal marsh habitat. Engineering controls would
be implemented within the proposed channel diversion to provide equivalent habitat quality and ecological
function. Depending on the final design, habitat quality could actually be improved from that currently within
Hershey Run from not only the elimination of exposure to CoPC-containing sediments but also from the
enhancement of ecological diversity. Engineering controls such as diversion structures, retention ponds, and
channel lining material could be incorporated into the design to provide spawning and cover habitat and otherwise
facilitate the enhancement of habitat diversity.
Overall Protection of Human Health and the Environment
As noted previously, the HHRA reported potential hypothetical future human health risks to construction workers
if exposed under some future use scenario. Appropriate deed restrictions would prevent such future exposure
scenarios. Ongoing natural attenuation processes at the Site, together with covering and/or excavation and disposal
of surficial soil NAPL material would eliminate or mitigate associated exposure pathways. Subsurface NAPL
zones are technically impracticable to remove and would therefore remain in the subsurface where they are
adversely affecting human health and the environment. Rechannelization of Hershey Run and backfilling of the
old channel would be effective in eliminating potential exposure to NAPL materials in the current channel. These
actions would significantly reduce potential exposure and hence, implementation of Alternative 4 would sufficiently
protect both human health and the environment.
Compliance with ARARs
As noted for the previous alternatives, no chemical-specific ARARs have been identified for Alternative 4. The
applicable location-specific ARARs are the Fish & Wildlife Coordination Act and NHPA, which can be complied
with by avoiding, as much as possible, areas designated as having archaeological value, or by conducting a Phase
II Cultural Resources Survey if potentially significant sites may be impacted by remediation. Applicable action-
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specific ARARs can be complied with and include RCRA, DOT, CERCLA, OSHA (federal) and the Delaware HSC
and hazardous waste codes.
Long-term Effectiveness and Permanence
Implementation of Alternative 4 is expected to meet the RAOs for the Site and be effective over the long term.
Excavation and backfilling would prevent exposure to surface materials in the affected portions of the Upland Area
and permanently remove this material. The new channel would adequately facilitate drainage but reduce potential
exposure of biota to NAPL. This channel would provide an improved environment for the reestablishment of the
benthic community and habitat. The immobility of subsurface NAPL indicates that off-site migration of these
materials would be limited, and NAPL zones would remain confined to limited areas of the Site subsurface.
Quantities of recoverable NAPL would be permanently reduced through the pilot study. Ongoing natural processes
would address constituents in groundwater and this would be confirmed through monitoring. Monitoring would
be used to confirm ongoing natural attenuation and that the on-site containment unit is operating effectively over
the long term.
Reduction of Toxicity, Mobility or Volume through Treatment
Alternative 4 provides for substantial containment, removal, and treatment/disposal of recoverable NAPL and
surficial NAPL deposits, and NAPL in the current Hershey Run channel would be isolated in place. This alternative
would result in significant reductions in mobility, volume, and potential toxicity through removal of materials from
areas of the Site. Reductions would also occur as a result of ongoing natural attenuation, including degradation of
Site constituents.
Short-term Effectiveness
Some potential short-term impacts to on-site workers may be associated with removal of material and construction-
related risks during rechannelizing of Hershey Run. Short-term impacts to on-site workers may be associated with
potential emissions of semi-volatile compounds and fugitive dust to the atmosphere during material excavation and
handling. Containment measures such as temporary enclosures would not be feasible to reduce or eliminate these
impacts due to difficulties associated with internal air handling and the potentially high concentrations of airborne
chemicals that could result from significant soil disturbance. However, particulate emissions could be addressed
by dust control technologies, such as water or foam sprays, and potential exposures to on-site workers would be
further mitigated through the use of PPE and procedures detailed in a project-specific HASP.
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Although there will be some increased traffic due to construction vehicles, the use of on-site containment/disposal
and the potential use of backfill material would significantly reduce the off-site truck traffic (up to 10,000 one-way
trips) that would arise from off-site disposal. Since this alternative does include construction activities in Hershey
Run, the benthic community in the channel and affected wetland areas would be impacted. This could result in not
meeting the RAO to reduce potential unacceptable risks to the structure and function of the benthic community.
Implementability
Materials and equipment necessary for the implementation of this alternative are expected to be readily available.
Work in the Hershey Run drainage area may present challenges for access and operation of construction equipment.
Some specialized equipment may be necessary if the wetland areas have poor bearing capacity. Monitoring
equipment, NAPL recovery containers, and specialized services such as laboratory analysis would be required to
implement this alternative and are readily available. However, the purpose of the pilot study would be to evaluate
the technical implementability of NAPL recovery efforts. In addition, pursuit of a Tl designation for subsurface
NAPL zones and associated groundwater impacts will require development and approval of a Tl evaluation and
Tl waiver. The presence of cultural artifacts of archaeological significance would need to be addressed before any
excavation activities could be implemented. The Wright Farmstead site is located adjacent to the K Area and
prehistoric Sites 3 and 5 in the Upland Area are reportedly of significant archaeological value and could be
disturbed by remedial activities.
Cost
The capital cost to implement Alternative 4 is approximately $9,174,000. The estimated annual cost of O&M is
approximately $117,000, resulting in a total present worth cost (over 30 years) of approximately $10,920,000.
Details on the estimated cost to implement Alternative 4 is presented are Table 4-9.
4.7 Alternative 5 - Hershey Run Sediment Removal, Upland Surface Soil and Sediment
Removal, Off-site Thermal Treatment, Groundwater Recovery and Treatment,
Monitoring, Institutional Controls and Pilot Study.
Description
Implementation of Alternative 5 would involve:
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• hot spot dredging of Hershey Run channel;
• excavation of surficial NAPL in the Fire Pond, South Ponds, K Area, Process/Drip Track Areas, the
Loading Dock Area, and Wood Storage Area;
• off-site treatment of the excavated material through thermal treatment (incineration or thermal desorption);
• NAPL recovery pilot study for wells MW-2A and MW-8A; and
• pumping of groundwater for subsequent treatment.
Following the construction of access roads in the Hershey Run Drainage Area and appropriate staging areas at
adjacent locations, approximately 100,000 cy of sediment would be removed from the Hershey Run channel. The
stream would be diverted in sections, and sediment in areas at which NAPL has been identified (i.e., hot spots)
would be removed by mechanical means. Areas to be removed would include areas where NAPL was visually
observed during the RI. However, additional volumes have been included due to the likelihood that the RI data did
not completely define the impacted area. Consequently an order of magnitude estimate of 100,000 cy is being used
in this evaluation but could vary following collection of design data and/or during actual construction. The
removed sediments would be stabilized with an appropriate material to reduce water content during transportation.
It is currently anticipated that the removed sediment would be transported to Calvert City, Kentucky for treatment.
In excavated areas that appear to be prone to erosion, appropriate control measures would be taken (e.g., placement
of gravel and/or rip rap).
Surface soils containing NAPL deposits in the upland area (approximately 50,000 cy from Fire Pond, South Ponds,
K Area, Process/Drip Track Area, Loading Dock, and Wood Storage Area) would be excavated using conventional
equipment. These materials, would be transported to Calvert City, Kentucky to be thermally treated (i.e., thermal
desorption or incineration). Following removal, the excavated areas would be backfilled and graded to facilitate
surface water drainage and then vegetated.
Under Alternative 5, groundwater would be addressed through removal by pumping followed by treatment. A
series of recovery wells would be placed at strategic locations across the Site and a groundwater treatment facility
constructed. Other components of Alternative 5 include the NAPL recovery pilot study, long-term monitoring, and
institutional controls.
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Assessment of Environmental Effects and Post-Remedial Risk
Remedial Alternative 5 incorporates dredging or excavation of Hershey Run and excavation and filling of the Fire
Pond, South Ponds, K Area, and Upland Areas. Remedial alternatives for the Fire Pond, South Ponds, K Area, and
Upland Areas are essentially the same as in Remedial Alternative 4, except that materials in the Fire Pond, South
Ponds, and K Area would be excavated before backfilling. Therefore, the assessment of environmental effects and
potential post-remedial risk for these areas described in Section 4.6 is also applicable under this remedial
alternative. Effects of the remedial alternative on ecological and cultural characteristics of the Site are summarized
in Table 4-5.
Remediation in Hershey Run involves mechanical removal of sediment by dredging or excavation. Implementation
of this remedial alternative would result in increased ecological risks as a result of the dredging effort leaving a
"veneer" of residual sediments after the large-scale dredging effort is completed (Palermo, 1991). These residual
sediments typically contain depth-averaged CoPC concentrations indicative of the entire column of sediments to
be dredged. In the case of the Hershey Run, where the new surficial sediment typically contain lower CoPC
concentrations than deeper sediments, the surficial CoPC concentrations after dredging would be significantly
higher than the surficial bioavailable sediments that currently exist at the Site. Furthermore, potential sediment
removal will result in some disturbance and the subsequent release of sediments beyond the original removal area
(Moyan, 1996).
Results of the ecological characterization conducted during the RI, and additional field work conducted by Schuyler
and Johnson (1997), confirm that wetlands on the Site have high regional importance, which could be jeopardized
by disturbance during potential remedial activities. In particular, the Hershey Run Drainage Area and West Central
Drainage Area have relatively high ecological value, and Schuyler and Johnson found that the East and West
Central Drainage Areas had the greatest plant diversity of all wetlands on the Site. An important habitat type in
the West Central Drainage Area (and other on-site marshes) was the locally abundant Schoenoplectus fluviatilis
(river bulrush) emergent marsh. Field observations made by Schuyler and Johnson indicate that the Site (especially
the West Central Drainage Area) supports some of the highest quality and most extensive stands of Schoenoplectus
fluviatilis found in the Delaware Estuary drainage. This is a natural community of significance in Delaware, with
a current rarity rank of S2, meaning it is very rare (typically 6 to 20 known occurrences) and susceptible to
extirpation. Significant disturbance of this endangered community (e.g., through potential remedial measures such
as sediment removal or capping) would have severe and unacceptable detrimental effects on wetland quality either
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through physical destruction of important plants and habitat or by enhancing invasion of Phragmites into areas
disturbed by remedial activities. In addition, disturbance of Site drainage areas (marshes) would conflict with the
associated RAOs for sediment.
Overall Protection of Human Health and the Environment
As noted previously, the HHRA reported potential hypothetical future human health risks to construction workers
if exposed under some future use scenario. Extensive removal of Site materials followed by backfilling would
reduce the volume of material to which human or ecological receptors could be exposed. However, the intrusive
nature of the removal components of this alternative would destroy benthic and terrestrial communities in the
affected portions of Hershey Run, drainage areas, and upland areas. Protection of human health and the
environment associated with the transport and thermal treatment of Site materials would depend upon careful
transportation/handling and appropriate operation and monitoring by the treatment facility owners/operators.
Recovery and treatment of groundwater would serve to limit the quantity of groundwater that may potentially be
subject to off-site migration, and thereby provide additional protectiveness, although RI data indicate very limited
potential for off-site migration. The subsurface NAPL zones do not pose a significant threat to human health and
the environment due to lack of mobility, and Site constituents that may become mobile in groundwater are subject
to reductions through ongoing natural attenuation processes.
Compliance with ARARs
As noted for the previous alternatives, no chemical-specific ARARs have been identified for Alternative 5. The
applicable location-specific ARARs are the Fish & Wildlife Coordination Act and NHPA. The Fish & Wildlife
Coordination Act can be complied with by making efforts to minimize adverse effects upon fish and wildlife.
Alternative 5 involves removal of a significant volume of material from areas across the Site, which may make it
difficult to avoid destruction of habitat and sensitive communities during implementation. Efforts may be made
to comply with NHPA by avoiding work in areas designated as being of potential archaeological value or
conducting a Phase II Cultural Resources Survey, and other appropriate actions, as necessary. Applicable action-
specific ARARs can be complied with and include RCRA, Clean Water Act (CWA), DOT, CERCLA, OSHA
(federal) and the Delaware HSC and Hazardous Waste Codes.
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Long-term Effectiveness and Permanence
Removal and thermal treatment of Site soils and sediment followed by backfilling is an effective and permanent
means of addressing potential future exposure to these materials. The recovery and treatment of groundwater is
well understood, but the effectiveness of this approach to restoring groundwater impacted by creosote NAPL is very
limited when compared to a monitored natural attenuation approach that includes provision for long-term control
of exposure and potential source areas. This alternative would not be expected to provide a long-term remedy for
non-mobile subsurface NAPL zones because complete restoration would be technically impracticable.
Reduction of Toxicity, Mobility, or Volume through Treatment
Implementation of Alternative 5 would result in the reduction of volume, mobility, and toxicity posed by the
removed soil and sediment materials. Similarly, groundwater recovery and treatment would reduce the potential
toxicity of groundwater, but the intrusive nature of the pump and approach may have the unacceptable magnitude
effect of modifying subsurface hydrodynamics, which could adversely impact mobility or volume.
Short-Term Effectiveness
Significant short-term impacts to on-site workers may be associated with the very large and more complex scale
of operations onsite than the previous alternatives, as well as potential emissions of semi-volatile compounds and
fugitive dust to the atmosphere during more prolonged material excavation and handling. Containment measures
such as temporary enclosures would not be feasible to reduce or eliminate these impacts due to difficulties
associated with internal air handling and the potentially high concentrations of airborne chemicals that could result
from significant soil or sediment disturbance. However, particulate emissions could be addressed by dust control
technologies, such as water or foam sprays, and potential exposures to on-site workers would be further mitigated
through the use of PPE and procedures detailed in a project-specific HASP. The traffic resulting from the
transportation of approximately 150,000 cy or more of excavated materials (and associated backfill materials)
would be expected to be significant and could therefore pose a nuisance to the community and increase the chance
for accidents and spills of regulated materials. It is estimated that approximately 15,000 one-way truckloads of
material (or possibly more, if significant bulking occurs) would need to be transported over 800 miles to Calvert
City, Kentucky, to thermally treat the removed materials.
Implementation of Alternative 5 would also have short-term effects on Site biota and possibly archaeological sites.
The intrusive nature of Site preparation activities, road construction, and the actual removal would destroy and/or
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disrupt a large wetland environment. This would include habitats, flora, and fauna including any rare species or
communities. Additionally, the Site reportedly contains several artifacts of potential cultural and archaeological
significance that would likely be adversely affected during an intrusive remedial program as proposed under this
alternative. Therefore, implementation of Alternative 5 would have a significant impact in terms of wetlands and
habitats destroyed through construction of thousands of feet of haul roads to and along Hershey Run, and because
of truck traffic to transport materials for treatment and bring fill and other items to the Site. The anticipated
potential benefits of this alternative do not appear to warrant the significant adverse effects that would accompany
its implementation.
Regarding groundwater recovery and treatment, Alternative 5 would present several adverse short-term impacts,
as further discussed in Section 3.3.3. For example, a large number of monitoring and recovery wells would need
to be installed into the Columbia Formation shallow aquifer, which would unpredictably modify groundwater flow
paths and rates, and possibly jeopardize the integrity of the Potomac Formation clay layer or underlying deep (and
currently unaffected) aquifer if well construction were to penetrate this clay layer. In addition, the implementation
of surface soil and sediment excavation would conflict spatially with implementation needs for the groundwater
recovery and treatment systems, especially in the Process Area where surface soils and groundwater are both
affected. This type of conflict would reduce the short-term effectiveness of both remedial components and likely
necessitate an otherwise unnecessary extension of the remedial construction period. Finally, experience at other
similar sites with groundwater impacted by creosote NAPL suggest that recovery and treatment will not be effective
in the short term due to the practical inability to remove subsurface NAPL zones that appear to be acting as source
areas for Site groundwater. Recovery and treatment will therefore not provide substantial short- (or long-) term
benefits over the ongoing natural attenuation that is known to be occurring at this Site.
Implementability
Materials and equipment necessary for the implementation of this alternative are available. Several thousand feet
of haul roads would need to be constructed, especially along Hershey Run. Technical challenges may arise from
the need to drive heavy equipment over roads constructed over wetland soils that are likely to have very low bearing
capacities. If it was necessary for lighter, and therefore smaller pieces of equipment to be used, the construction
period, already expected to be several construction seasons, could be significantly extended. Flow diversion and
sediment removal in Hershey Run may also be hampered by tidal effects. Administrative feasibility may be
limited due to the presence of cultural artifacts of potential archaeological significance. Other potential constraints
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include restricted access and available thermal treatment capacity. Access to the Site is limited to a single guarded
entrance (24 hours per day) that is controlled by Ciba-Geigy. The lack of availability of needed trucks (on the order
of 20,000 trips) would significantly impede the rate of remedial operations. Removed sediment would have a high
water content that could also impede the thermal treatment process.
Regarding groundwater recovery and treatment, several adverse impacts would be expected in terms of
implementability constraints and short- and long-term limitations in effectiveness, especially as compared to a
monitored natural attenuation approach. Specifically, as further described under previous evaluation criteria and
in Section 3.3.3, these impacts/limitations include: 1) the technical impracticability of recovering subsurface NAPL
zones, 2) the potential negative effects caused by installation of numerous new monitoring and recovery wells, 3)
the time and spatial conflicts posed by implementing both the surface soil removal and groundwater recovery
components, 4) the limited effectiveness of a pump and treat approach requiring a complex recovery and treatment
system that will recover very large volumes of groundwater only to capture very small volumes of CoPCs, which
would not be cost effective or efficient, and 5) the long-term O&M associated with maintaining the systems over
the extended and untenable time periods expected to be necessary for groundwater restoration using this approach.
All these factors combine to indicate that groundwater restoration through extraction and treatment is technically
impracticable and therefore warrants a Tl waiver of applicable ARARs, coupled with appropriate monitoring and
institutional controls to track the effectiveness of natural attenuation over time and mitigate potential exposure
under future use scenarios. Further, the administrative feasibility of obtaining a Tl waiver is not expected to be
more constraining on implementability than designing, permitting, and maintaining technologies required under
Alternative 5.
Cost
The estimated capital cost to implement Alternative 5 ranges between approximately $33,430,000 and
$230,511,000. The estimated annual cost of O&M is approximately $2,026,000, and the 30-year present worth cost
of the alternative ranges from $64,530,000 to $262,000,000. These estimated costs are identified in Tables 4-10A
and 4-1 OB.
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5. Comparative Evaluation of Remedial Alternatives
This section compares the five potential remedial alternatives under consideration to address the presence of
creosote-related constituents at the Site. According to USEPA (1998), the purpose of this comparative evaluation
is to identify the advantages and disadvantages of each alternative relative to one another to identify the key
tradeoffs that must be balanced. In this comparative evaluation, the five potential remedial alternatives are
evaluated together, relative to each of the seven criteria used in the detailed evaluation. Based on this comparative
evaluation, a recommended alternative for the Site was selected and is presented below.
5.1 Overall Protection of Human Health and the Environment
As noted previously in this FS, under the current use scenario, there are no unacceptable risks to human health at
the Site. Under a hypothetical future use scenario, there may be potential risk to on-site construction workers. Risk
to the environment will be reduced through implementation of any of the five potential remedial alternatives
through, at a minimum, natural attenuation processes. However, Alternative 1 does not include monitoring to
confirm that it is protective. Alternative 2 includes a monitoring component and provides institutional controls to
address potential future risks to construction workers. Alternative 3 includes a good balance of components at
specific areas to address potential exposure from Site constituents to on-site workers and ecological receptors.
Alternatives 4 and 5 are also protective to potential future Site workers and the environment, but this is achieved
by generation of a larger waste stream that has to be managed and essentially relies on the same containment option
as in Alternative 3 to prevent potential exposure to residuals following excavation, without substantial added benefit
beyond the protectiveness provided by Alternative 3.
5.2 Compliance with ARARs
No chemical-specific ARARs are applicable to any of the alternatives. Since no action-related remedial responses
are included under Alternative 1, no action-specific and location-specific ARARs are applicable. It is anticipated
that all action-specific ARARs for each of Alternatives 2 through 5 can be achieved. However, a Tl waiver would
be necessary under each alternative to address the technical impracticability of recovering the immobile subsurface
NAPL zones and restoring groundwater. The presence of archaeological artifacts at the Site and the extensive
amount of removal included in Alternatives 4 and 5 may make it a more intensive program to allow the NHPA to
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be met. It is anticipated that the NHPA can be met for Alternatives 2 and 3. For Alternatives 2, 3, and 4, it would
be necessary to obtain Agency approval for an on-site landfill.
5.3 Long-Term Effectiveness and Permanence
Under Alternative 1, natural processes are expected to continue and reduce the bio-availability of NAPL materials.
However, Alternative 1 does not include a monitoring component to confirm this. Alternative 2 does include
monitoring of natural attenuation processes, but natural recovery is expected to take several years to be effective.
Alternatives 3, 4, and 5 are considered effective over the long term and permanent, subject to certain controls
including deed and access restrictions and, for Alternatives 3 and 4, maintaining the on-site landfill. Alternatives
4 and 5 involve a significant degree of intrusion into the wetland environments, the effects of which (e.g., habitat
destruction) would persist for several years with limited net benefit beyond other alternatives.
5.4 Reduction of Toxicity, Mobility, or Volume Through Treatment
All five alternatives include a natural recovery component that would result in reductions in exposure and potential
toxicity, mobility, and volume of Site CoPCs through time. However, only Alternative 5 involves an active
treatment component (through groundwater treatment and thermal treatment of solids). Relative to the area being
excavated, there is no additional benefit to thermal treatment over disposal since the area is excavated regardless.
Under Alternatives 3 and 4, the volume of affected material would not be reduced through treatment but mobility
would be reduced through removal and on-site containment. Alternative 3 also includes the placement of a layer
of soil over affected areas, in addition to removal, which serves to enhance the reduction in potential toxicity
(bioavailability) and mobility of residual CoPCs.
5.5 Short-Term Effectiveness
The five remedial alternatives under consideration are characterized by differing degrees of short-term
effectiveness. Alternative 1, which has no action-related remedial component, and poses no short-term threat to
human health and the environment. The implementation of Alternative 2 would involve a pilot NAPL-recovery
program and use of monitoring equipment, which would also be included in Alternatives 3, 4, and 5. However,
Alternative 3 would also involve the use of construction equipment in removal, capping, backfilling, and on-site
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landfill construction activities. Alternatives 4 and 5 are more involved (requiring significant access roads and
staging areas), and Alternative 5 would involve significant excavation and transportation activities. Excavation
activities would cause destruction of sensitive wetland environments, the effects of which are most pronounced for
Alternatives 4 and 5, and increased duration and potential for construction workers to be exposed to construction
hazaards and Site materials. Off-site transport of removed materials under Alternative 5 would increase local truck
traffic (thousands of truck trips over more than 800 miles for thermal treatment) during construction and increase
the potential for accidents involving potentially hazardous materials. For the less intrusive construction activities
proposed, engineering controls may be employed to adequately address short-term effects.
5.6 Implementability
Alternative 1 does not include any action-related remedial components and consequently poses no technical or
administrative implementability concerns. Invoking a Tl waiver for the immobile subsurface NAPL zones for
Alternatives 2 through 5 would require Agency approval. Similarly, use of an on-site landfill for on-site disposal
of removed materials in Alternatives 3 and 4 also would require Agency approval. The implementation of
Alternatives 4 and 5 would likely provide engineering challenges in terms of performing construction activities in
a wetland environment with construction of extensive access road and support areas over soils with potentially poor
bearing capacity. Additionally, Alternative 5 would require the use of thermal treatment capacity that may not be
readily available. Although permits are not required for remedial activities at this Site, the substantive requirements
of applicable permits would need to be met, to the extent possible.
5.7 Cost
The five alternatives being considered cover a wide range of costs. No cost is associated with the implementation
of Alternative 1. At the other extreme, the estimated present worth cost (over 30 years) of Alternative 5 is in the
range of approximately $64,530,000 to $262,000,000, depending on which type of thermal treatment is employed.
The costs for the other three alternatives are considerably less and are all within the same order of magnitude. The
estimated present worth costs (over 30 years) of Alternatives 2,3, and 4 are approximately $2,410,000, $8,490,000,
and $10,920,000, respectively.
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5.8 Identification of Recommended Alternative
The purpose of this section is to identify the recommended remedial action for the Site and the rationale behind the
recommendation. Recommendation of this alternative is based upon the individual analysis of effectiveness,
implementability, and cost presented in Section 3, the detailed evaluation of remedial alternatives in Section 4, as
well as the comparative analysis of remedial alternatives presented above. Additional considerations include the
potential for modification and/or combination of particular alternatives based upon the identification of key
tradeoffs.
As a result of those analyses, the recommended remedial action for the Site is the implementation of Alternative
3, which includes natural recovery for sediments; excavation of Upland Area surface soil NAPL deposits with on-
site disposal; containment (cap/cover) for the Fire Pond, South Ponds, and K Area; monitored natural attenuation
and a Tl waiver for groundwater and subsurface NAPL zones; plus monitoring, institutional controls, and a NAPL
recovery pilot study. The total estimated present worth cost of this alternative is $8,490,000.
Alternative 3 is the recommended alternative based on the following considerations:
1. Human Health Risk Assessment - The HHRA identified no Site-related human health risks to potential
receptors at the Site, the only exception being potential exposure to future on-site workers under certain use
scenarios. Alternative 3 would address this potential exposure through deed restrictions and standard health
and safety measures during construction. As a result, Alternative 3 is protective of human health.
2. Ecological Risk Assessment - PAHs were identified as the primary CoPC in soil and sediment with lead and
zinc being secondary. It also identified direct contact with PAH-containing soil and sediment as the primary
exposure pathway for biota in areas with the highest PAH concentrations at the Site. Alternative 3 achieves
risk reduction to potential receptors through elimination or mitigation of potential exposure pathways.
Impacted surface soils in the Upland Area would be isolated through on-site consolidation and placement
within an on-site landfill. Materials within the Fire Ponds, South Ponds, and K Area would be encapsulated
in place. Sediment within Hershey Run would continue to be encapsulated through ongoing sediment
deposition, providing additional materials over the existing 1 foot of relatively clean sediment currently located
throughout the majority of Hershey Run.
BLASLAND. BOUCK & LEE, INC.F:\usERatFMAR99\57391832.WPD-9/30W engineers & scientists 5-4
A R 3 I 4 2 0 8
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3. Surface Soil Removal Activities - Affected surface soils in the Upland Area would be excavated and
consolidated at an on-site landfill. This landfill would be constructed in accordance with applicable
requirements and would provide for the long-term isolation of these materials from the environment in a timely
and effective manner.
4. Monitored Natural Attenuation for Site Groundwater - An evaluation of the groundwater sampling data
indicates that the constituents of interest at the Site are undergoing natural attenuation. As a result, constituents
are expected to continue to decrease in concentration over time. This conclusion is supported by the Site-
specific attenuation rate constants developed for the Site which predict compliance with groundwater standards
at the property boundary.
5. Tl Waiver for Subsurface NAPL - Subsurface NAPL zones in the upland portion of the Site are restricted
in migration through limited entry pressure, high viscosity, low solubility of the NAPL, and low permeability
of the confining clay units. However, additional evaluation will be necessary to support both the Tl waiver and
the monitored natural attenuation approach as described in Section 3.3.3.
6. Removal of Potentially Recoverable NAPL - The presence of potentially recoverable NAPL is limited to only
two of the monitoring wells (MW-2A and MW-8A) located in the upland portion of the Site near the Process
Area. This alternative would attempt the recovery of NAPL from this area through implementation of a pilot
study.
7. Preservation of Wetland and Archaeological Areas - This alternative minimizes potential impacts to
wetlands and potentially valuable archaeological areas at the Site. Excavation efforts and the need for
construction infrastructure (e.g., haul roads) are minimized in these sensitive areas in favor of equally
protective, nonintrusive remedial components.
8. Future Site Redevelopment - DuPont will continue to retain ownership of the Site for the foreseeable future,
and appropriate deed restrictions will be obtained for the property. The upland portion of the property will
continue to remain zoned for industrial use and the wetland and forested areas will remain intact.
BLASLAND. BOUCK & LEE. INC.F:\USEFS\LFMAR99\57391832.WPD-9/30,99 engineers i scientists 5-5
A R 3 I 4 2 0 9
DRAFT
In summary, risk reductions and the RAOs can be accomplished by implementing institutional controls,
capping/covering certain soils/sediments, Upland Area surficial soil removal and on-site disposal, monitoring the
progress of ongoing natural attenuation, and the removal of recoverable NAPL. Furthermore, the isolation of
surface soils within an on-site landfill would avoid the difficulty and limitations associated with removing
significant soil quantities for off-site treatment. Finally, Alternative 3 is protective of human health, reduces
ecological exposure to those areas containing the highest concentrations of PAHs, and will achieve the RAOs
identified for the Site.
BLASLAND, BOUCK & LEE. INC.F:\usERRLFMAR99\5739i832.WFD-9/30/99 engineers ^ scientists 5-6
A R 3 I 4 2 I O
DRAFT
6. References
Blasland, Bouck & Lee. 1999. Remedial Investigation Report (Revised Draft), Former Koppers Company, Inc.
Newport Site, Newport Delaware, April 1999.
BBL. 1997. Remedial investigation report, former Koppers Company, Inc., Newport Site, Newport, Delaware.
Prepared for Beazer East Inc., Pittsburgh, PA, and E.I. DuPont de Nemours and Company, Inc. Blasland, Bouck
& Lee, Inc., Syracuse, NY.
DOD. 1994. Remediation Technologies Screening Matrix and Reference Guide, DOD Environmental Transfer
Committee, October 1994.
Environmental Standards, Inc. 1997. Human Health Risk Assessment For the Former Koppers Company, Inc. Site,
Newport Delaware, September 26, 1997.
Exponent. 1997. Ecological Risk Assessment - Former Koppers Company, Inc. Newport Site (Newport, Delaware).
Grubb and Sitar. 1994. Evaluation of Technologies for in-situ Cleanup ofDNAPL Contaminated Sites, August
1994.
Jordan. 1962. Stratigraphy of the sedimentary rocks of Delaware. Delaware Geological Survey Bulletin No. 14.
Karickhoff, S.W., and Morris, K.R. 1985. Environ. Toxical. Chem., 4:469-479.
Kellogg, D.C., and W.P. Catts. 1996. Phase IB archeological survey of selected areas of the former Koppers
Company, Inc. property Newport, Delaware. John Milner Associates, Inc., West Chester, PA.
MAAR Associates, Inc. 1995. Phase IA Cultural Resources Survey for the Former Koppers Company, Inc.
Property, New Castle County, Delaware, February 1995.
BLASLAND, BOUCK & LEE, INC.F:\usER9iFMAFW5739i832.wFD--9/30W engineers & scientists D-T
A R 3 I 4 2 I I
DRAFT
Milner and Associates, Inc. 1996. Phase IB Archaeological Survey of Selected Areas of the Former Koppers
Company, Inc. Property, Newport, Delaware, August 1996.
Palmero, M.R. 1991. "Equipment Choices for Dredging Contaminated Sediments." Remediations.
PTI. 1997a. Draft technical memorandum. Discussion of statistical methods used to establish ecotoxicity
thresholds from toxicity test data for the Koppers Company, Inc., Newport Site. Prepared for Beazer East, Inc.,
Pittsburgh, PA, and E.I. du Pont de Nemours and Company, Wilmington, DE. PTI Environmental Services,
Bellevue, WA.
PTI. 1997b. Draft technical memorandum. Analysis of sediment and soil toxicity data for the former Koppers
Company, Inc., Newport Site. Prepared for Beazer East, Inc., Pittsburg, PA, and E.I. du Pont de Nemours and
Company, Wilmington, DE. PTI Environmental Services, Bellevue, WA.
Schuyler, A.E., and E.A. Johnson. 1997. Zoological, botanical, and natural community inventory and assessment
of 136 acres of wetlands Koppers Site Newport, Delaware. Final Report. The Nature Conservancy, Delaware
Chapter, Newark, DE.
Sumeri, A. 1996. "Dredged Material is Not Spoil: A Report on the Use of Dredged Material in Puget Sounds to
Isolate Contaminated Sediments," Proceedings of the Western Dredging Association 17th Technical Conference
and 29th Annual Texas A&M Dredging Seminar, June 1996.
SCS. 1970. Soil Survey of New Castle County Delaware, (Washington, DC, 1970).
Sundstrom and Pickett. 1971. The Availability of Ground Water in New Castle County, Delaware, University of
Delaware Water Resources Center.
Sundstrom and Pickett. 1967. The Availability of Ground Water from the Potomac Formation in the Chesapeake
and Delaware Canal Area, Delaware, University of Delaware Water Resources Center.
USEPA. 1998. Selecting Remediation Techniques for Contaminated Sediment, Washington, DC.
BLASLAND. BOUCK & LEE. INC.F:\usERRLFw_AR99\5739i832.wpD--9/30W engineers & scientists 6-2
A R 3 I 4 2 1 2
DRAFT
USEPA. 1997a. Ecological Risk Assessment, Koppers Company, Inc., Site, Newport, Delaware. U.S.
Environmental Protection Agency, Office of Emergency and Remedial Response, Environmental Response Team.
USEPA. 1997b. Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting
Ecological Risk Assessments. Interim Final. U.S. Environmental Protection Agency, Environmental Response
Team, Edison, NJ.
USEPA. 1997c. Use of Monitored Natural Attenuation At Superfund, RCRA Corrective Action, and Underground
Storage Tank Sites. Office of Solid Waste and Emergency Response.
USEPA. 1996. Best Demonstrated Available Technology (BDAT) Background Document for Wood Preserving
Wastes: F032, F034, andF035, Final, April 1996.
USEPA. 1993. Guidance for Evaluating the Technical Impracticability of Ground-Water Restoration, Interim
Final, September 1993.
USEPA. 1992. Framework for Ecological Risk Assessment. EPA/630/R-92/001. U.S. Environmental Protection
Agency, Risk Assessment Forum, Washington, DC.
USEPA. 1991. Administrative Order on Consent for Remedial Investigation/Feasibility Study: Koppers Company,
Inc. Site, Docket No. III-91-16-DC, Philadelphia, PA, October 4, 1991.
USEPA. 1988. Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA, Interim
Final, October 1988.
BLASLAND, BOUCK & LEE, INC.F:\uSEfiaLWLAK99\57391832.WPD--9/30W engineers & scientists 6-3
A R 3 I 4 2 I 3
TablesB L A S L A N D , B O U C K & L E E . INC.
e n g i n e e r s & s c i e n t i s t s
A R 3 I 4 2 1 4
DRAFT
Table 1-1
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Welaht-of-Evldenca Approach and Ranking of Measurement Endnoints for the Ecological Risk Assessment*
Measurement EndpointField Survey Toxicity Tests
Assessment EndpointBenthic
Vegetation Community Sediment Fish Frog Earthworm Model
Food Literature-Web Based Effects
Levels
CO
•p-ro
en
Structure and Function 1. Wetland communities—structure and function
2. Aquatic benthic communities—structure andfunction
3. Upland soil community—function
4. Terrestrial plant community—structure andfunction
Toxicity and Reproduction 5. Fish populations and communities—directtoxicity and reproductive impairment
6. Amphibian populations—recruitment
7. Piscivorous birds—direct toxicity andreproductive impairment
8. Worm-eating birds—direct toxicity andreproductive impairment
9. Carnivorous birds—direct toxicity andreproductive impairment
10. Carnivorous mammals—direct toxicity andreproductive impairment
11. Omnivorous mammals—direct toxicity andreproductive impairment
12. Terrestrial herbivores—direct toxicity andreproductive impairment
1 21
32
1
1
1
1
1
1
4
3
* Numbers in the table indicate the priority ranking for each measurement endpoint used in the weight-of-evidence approach to risk characterization, with 1 beingthe highest priority.
b Primarily physical effects on plants weathered NAPL deposits present on surface soils.
573tbl
IDRAFT
Table 2-1
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Summary of Federal and State ARARs and TBCs
Regulation Citation DescriptionARAR/TBC
Assessment Rationale
CO
•c-ro
FEDERAL ACTION-SPECIFIC ARARs
Resource Conservationand Recovery Act (RCRA)
Clean Water Act (CWA)Discharges to Waters ofthe United States
Management ofRemediation Waste UnderRCRA
Department ofTransportation (DOT)Requirements
40 CFR 260-270
40 CFR 264.552
40 CFR 258.60
40 CFR 268 - Land DisposalRestrictions
33 CFR 330.5, Appendix A, (26)
40 CFR 230.10Restrictions to Discharge
EPA 530-F-98-026October 1998
49 CFR Parts 171 through 179
Corrective Action provisions of RCRA
Corrective Action Management Units(CAMU)
Subtitle D landfill regulations
RCRA restrictions regarding land disposalof hazardous wastes
Identifies the nationwide permitrequirements for dredged or fill material
Restricts the discharge of dredged or fillmaterial if a practicable alternative wouldhave less adverse impact on the aquaticecosystem
Describes regulations and policiesapplicable to RCRA remediation wastes.
Regulations regarding the intrastate andinterstate shipping of hazardous materials
PotentiallyApplicable
PotentiallyApplicable
PotentiallyRelevant andAppropriate
PotentiallyApplicable
TBC
PotentiallyApplicable
TBC
PotentiallyApplicable
Applicable to specific remedial activities.
Applicable to on-site containment facilityfor removed materials.
May be relevant and appropriate for on-site management of materials.
Restricts land disposal of wood treatmentwastes (RCRA F034) that are managed.
Applicable to dredging or cappingactivities if implemented in surface waters.
Applicable if sediment removal is acomponent of a remedial alternative.
Describes CAMU requirements for on-sitetreatment/disposal.
Applicable if hazardous materials areshipped off-site.
W2W99F \USFRSHRUAR9W573TB2-1 WPD Page 1 of 5
DRAFTTable 2-1
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Summary of Federal and State ARARs and TBCs(Cont'd)
Regulation
ComprehensiveEnvironmental Recovery,Compensation and LiabilityAct
Section 10 of the River andHarbors Act
"Guidance for Evaluatingthe Technical Impractibilityof GroundwaterRestoration*
Citation
42 USC 9601Section 121 (e)
Section 121 (d)(4)
33 U.S. C. Section 40333 C.F.R. Part 320-330
OSWER Directive 9234.2-25(September 1993)
Description
Waives the requirement to obtain federal,state, and local permits for on-site CERCLAactions.
Technical Impracticability Waiver
Permit requirements for dredging activities
Establishes USEPA's policy and proceduresfor demonstrating technical impracticabilityof groundwater remediation
ARAR/TBCAssessment
Applicable
Applicable
TBC
TBC
Rationale
Applicable to CERCLA actions.
Applicable because groundwaterremediation cannot be achieved due totechnical impracticability from anengineering perspective.
Although permit not required, dredgingactivities to remove sediment fromnavigable waterway would be subject tothese requirements.
STATE ACTION-SPECIFIC ARARs
Delaware HazardousSubstance Cleanup Act(HSCA)
Regulations GoverningControl of Air PollutionRegulation No. 2
7 Delaware Code, Chapter 91
7 Delaware Code, Chapter 60
7 Delaware Code, Chapter 60
General Provisions for the cleanup ofHazardous material
Establishes the Department of NaturalResources and Environmental Control'spower to waive requirements forenvironmental permits for on-facilityactivities during a remedial action
Establishes permitting requirements forsources of air emissions
TBC
Potentiallyapplicable
TBC
Identifies issues to be addressed ifgroundwater remediation is impracticableat the site.
Since RI/FS is subject to USEPAoversight, Delaware HSCA is to beconsidered.
Applicable to CERCLA actions.
Applicable if in-situ or ex-situ remedialalternatives result in air emissions.
W2O99F:\USERS\LRALAR9aS73TB2-1 WPO Page 2 of 5
CO
DRAFTTable 2-1
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Summary of Federal and State ARARs and TBCs(Cont'd)
Regulation
Delaware regulationsgoverning construction ofwater wells
Regulations governinghazardous waste
Sediment and Stormwaterregulations
Citation
7 Delaware Code, Chapter 60
7 Delaware Code, Chapter 63Chapter 91
7 Delaware Code, Chapter 60
Description
Contains requirements for location, design,installation, use, disinfection, modification,repair, and abandonment of wells andassociated pumping equipment.
Includes manifest program for transport ofhazardous waste
Contains stormwater control guidelinesapplicable for construction or land changes
ARAWTBCAssessment
TBC
Potentiallyapplicable
TBC
Rationale
Applicable if recovery or additionalmonitoring wells are to be installed at theSite.
Applicable if remedial actions result in thetransport of hazardous waste.
Erosion controls required if uplandremedial activities involve excavation ofsurface areas greater than 5,000 ft2
FEDERAL CHEMICAL-SPECIFIC ARARs
CWA - Ambient WaterQuality Criteria (AWQC)
"Evaluation ofTechnologies for In-SituCleanup of DNAPLContaminated Sites"
40 CFR 131-Water QualityStandards
EPA/600/R-94/120 August 1994(USEPA Guidance Document)
Criteria for protection of aquatic life and/orhuman health depending on designatedwater use.
Provides an assessment of in-situ treatmenttechnologies to address subsurface NAPL
TBC
TBC
Requirements for protection of aquatic life
To be considered given the presence ofNAPL at the site.
STATE CHEMICAL-SPECIFIC ARARs
Delaware Surface WaterQuality Standards
7 Delaware Code, Chapter 60 Mandates that surface water for streams,lakes, rivers, and standing water inwetlands be maintained at a qualityconsistent with public health andrecreational purposes, for the propagationand protection of fish and aquatic life, andfor other beneficial uses of water.
TBC Site-specific Ecological Risk Assessmentspecifies requirements for the protectionof aquatic life.
W2M9F \USERS\LR\LAR99tf73TB2-1 WO Page 3 of 5
DRAFTTable 2-1
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Summary of Federal and State ARARs and TBCs(Cont'd)
Regulation Citation DescriptionARAR/TBC
Assessment Rationale
FEDERAL LOCATION-SPECIFIC ARARs
ComprehensiveEnvironmental Response,Compensation and LiabilityAct of 1980
Fish and WildlifeCoordination Act
Management Act of 1972;Coastal Zone ActReauthorizationAmendments of 1990 etseq
Land Use in the CERCLARemedy Selection Process
Executive Order 11990 -Protection of WetlandsFloodplain Management
Executive Order 11988
National HistoricPreservation Act (NHPA)
42U.S.C. 9601 etseq.
16 USC 661-666.33 CFR 320 - 330
15 CFR 93016 USC 1451-1464
OSWER Directive 9355.7-04
40 CFR 6.30242 CFR 26961 amended by52 FR 34617
40 CFR 6, App. A42 USC 4321
36 CFR 800, 40 CFR 6.30116 USC 470 et. seq.
36 CFR 6516 USC 469
Establishes mechanism for remediatinginactive hazardous waste sites.
Requires federal agencies to consult withthe U.S. Fish and Wildlife Service and Statewildlife resources agency in order toconserve wildlife resources duringremediation
Requires federal agencies conducting orsupporting activities, to directly conduct orsupport those activities in a mannerconsistent with the approved appropriateState coastal zone management program.
Identifies considerations for incorporatinganticipated future land use in the remedyselection process
Requires federal agencies to avoid adverseimpacts to wetland areas under federallyundertaken, financed, or assistedconstruction
Requires federal agencies to take actions tominimize the short- and long-term adverseeffects associated with modifications offloodplains
Preservation of historic properties andlandmarks
Preservation of artifacts
ARAR
PotentiallyRelevant andAppropriate
TBC
TBC
TBC
TBC
PotentiallyApplicable
ARAR
Site is CERCLA-listed.
Applicable to federal agencies, but maybe relevant and appropriate to activities inany surface water body that may beimpacted by remedial activities.
Relates to federal agencies, but may berelevant and considered relative toactivities that affect the coastal zone asdesignated by the State of Delaware.
Provides guidance for consideration offuture site land use in selection of a site
Applicable only to federal agencies; maybe considered since the selected remedialalternative includes work in wetland areas.
Applicable only to federal agencies; maybe considered for remedial activitiesperformed in the floodplains.
Potential historical/archaeological siteshave been identified at the site
Potential historical/archaeological siteshave been identified at the site
W2W99F \USERSMR\LAR99\573TB2-1 WPO Page 4 of 5
Table 2-1
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Summary of Federal and State ARARs and TBCs(Cont'd)
DRAFT
Regulation
Endangered Species Act
Citation
16 USC 1531 efseg.50 CFR 402
Description
Requires efforts to ensure that thecontinued existence of any endangered orthreatened species and their habitats willnot be jeopardized by a site action
ARAR/TBCAssessment
PotentiallyRelevant andAppropriate
Rationale
May be relevant and appropriate ifendangered species habitat areas wouldbe impacted by site remediation activities.No federally endangered species areknown to frequent the area.
Occupational Safety andHearth Act (OSHA)
29 CFR Parts 1910,1926,1904 Established requirements for worker safetyand health
ARAR Applicable to any action taken at the site.
STATE LOCATION-SPECIFIC ARARs
Wetlands Regulations
Ground Water ProtectionStrategy of 1984
Regulations GoverningUse of Subaqueous Land
7 Delaware Code, Chapter 66
7 Delaware Code, Section 7212
Stipulates permit requirements fordisturbances in and around wetland areas
Identifies groundwater quality to beachieved during remedial actions based onaquifer characteristics and use.
Requires that activities that are conductedon private subaqueous lands (submergedlands and tidelands) in the State bepermitted
TBC
TBC
TBC
To be considered if work is to beconducted in the tidal wetland areas. Astate and/or county permit may berequired.
The aquifer classification should beconsidered during design andimplementation of the selected remedy.
To be considered if dredging activities areto occur.
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W2M9F:\USERSM_RMAR99\573TB2-1 WPO Page 5 of 5
Table 2-2
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Ecological and Cultural Characteristic* of Araaa Potentially Subject to Remediation
DRAFT
Areas Potentially Subject to RemediationCharacteristic Hershey Run West Central Marsh Fire Pond South Ponds Area KArea Upland AreasHabitat type
Habitat quality
Drainageway (channel)within tidal marsh
Tidal marsh Open, man-made water bodywith forested border
Plant communitystatus
Diverse community withlimited Phragmttasinvasion
Diverse community with
invasion
Ephemeral man-made waterbody with uplandscrub/forested border
Upland herbaceous/scrub Upland herbaceous
Channel within functionally Functionally intact wetlandintact wetland complex complex
Pond offers habitat for aquatic Ponds are shallow andanimals; bordering land is ephemeral, bordering land isforest cover forest cover
Relatively low due toextensive secondaryrevegetation
Relatively low due toextensive secondaryrevegetation
Pond has some emergent Ponds are sparsely Dominated by early Dominated by earlyvegetation; forest has diverse vegetated; forest has diverse successional herbaceous successional herbaceousflora of native and non-native flora of native and non-native plants, including non- plants, including non-species species native species native species
3DCO
ro
Wildlife species Surveys indicate diverse Surveys indicate diverse Pond and bordering forest Ponds have low diversity; Relatively good diversity Relatively good diversitydiversity and abundant insect and and abundant insect and have relatively good diversity bordering forest has relatively
vertebrate populations vertebrate populations good diversitypresent in marsh present in marsh
Ecologicalimportance/function
Landscape/regionalimportance
Significantarchaeologicaland culturalresources
The marsh's high diversityof native plant speciesenhances the channel'secological function andwildlife diversity
Among the least disturbedfreshwater tidal marshes ofthe Delaware estuary(Schuyler & Johnson1997); part of largerregional system, includingChurchman's Marsh,providing forage sites forwetland birds
High diversity of nativeplant species enhancesecological function andwildlife diversity
Pond may provide amphibian Ponds offer minimal Potential nesting andspawning habitat. Forest may ecological habitat. Forest foraging habitat for someprovide habitat for breeding may provide habitat for common bird and insectand migratory birds, other breeding and migratory birds, specieswildlife other wildlife
Among the least disturbed Minimal, pond contributes to Minimalfreshwater tidal marshes of habitat diversity on Site, but isthe Delaware estuary small and isolated from other(Schuyler & Johnson similar habitats in the region1997); high qualityoccurrence of state-rareriver bulrush; part of largerregional system, includingChurchman's Marsh,providing forage sites forwetland birds
Minimal
None None None None Wright farmstead site isadjacent to K Area
Potential nesting andforaging habitat for somecommon bird and insectspecies
Minimal
Prehistoric Sites 3 and 5in Upland Area potentiallyaffected by remediation
DRAFT
3DCO
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Table 3-1A
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potentially Applicable Sediment Remedial Technologies1
IV?General Response Action/
Remedial TechnologyProcess Option Description
A. No Action
No remedial activities performed.
Preliminary Assessment
Implementable.
B. Institutional Controls
Access restrictions
Monitoring
Deed restrictions
Constraints, such as security guards, fencing and signs, would be placed on property to limitaccess.
Periodic visual observations and/or field sampling would be used to monitor Site conditions.
Constraints would be placed on future use of land adjoining Hershey Run.
Implementable.
Implementable.
Implementable.
C. In-Place Containment
I. Capping
II. Hydraulic Modification
Natural Cover
Engineered Capping/Armoring3
AquaBlok.TM
Asphalt cap
Physical process of continuing deposition of progressively cleaner material covering andmixing with existing material to reduce bioavailability of creosote components.
Design of a cap comprising layers of materials (e.g., clean sediment, sand, gravel, cobbles,geotextile) placed over in-situ sediment to isolate constituents and prevent erosion.
Engineered pellets are placed through the water column and settle over the sediment. Thebentonite clay coatings absorb water, coalesce, and form an impermeable layer.
Application of an asphalt or concrete layer over sediment
Multi-media cap
Rechannelization
Sedimentation Basin
Clay and synthetic membrane covered by soil over sediment.
Construction of a "new" channel and diversion of the Hershey Run.
Enlarging a portion of Hershey Run to reduce velocity and promote sediment deposition. Thecollected sediment may be removed periodically.
Implementable.
Implementable.
No known full-scaleapplication to creosote insediment.
Not practical for submergedsediment.
Potentially implementable.
Potentially implementable.
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Table 3-1A DRAFT
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potentially Applicable Sediment Remedial Technologies1
(cont'd.)
General Response Action/Remedial Technology
D. Sediment Treatment
I. Biodegradation
II. Immobilization
III. Extraction, In-Situ
Process Option Description Preliminary Assessment
30CO
rofNJCO
Natural1
Enhanced1
Stabilization/Solidification1
Vitrification
Vacuum
Steam
Liquid
Naturally occurring PAH degradation by microorganisms present at the Site in an aerobic oranaerobic environment.
Addition of nutrients (e.g., oxygen, minerals, etc.) or cultured microorganisms to the sedimentto facilitate or improve the rate of natural biodegradation.
Chemically immobilize materials by injecting and mixing a stabilization/solidification agentinto the sediment
Stabilizes or destroys constituents by melting sediment utilizing electrical currents. The meltedmaterial then solidifies to form a glass-like monolith.
Create vacuum in sediment through a well; chemical constituents drawn in and extracted.
Inject steam into sediment, so that chemical constituents volatilize and are removed viaextraction wells.
Solvents introduced in sediment via injection wells, extraction wells recover solvent andextracted chemical constituents.
Implementable.
Potentially implementable ex-situ; aquatic environment maydilute added nutrients tolevels too low for uptake bymicroorganisms.
Not implementable ex-situdue to land ban. In-situprocess not yet sufficientlydeveloped.
Not feasible for submergedsediment. Ex-situ operationshave not been demonstratedfull scale with sediment.
Not feasible in submergedsediment.
Not feasible in submergedsediment.
Not feasible for submergedsediment.
W2W99F \USERSVLRUAR99tf73TB31AWPO (See Notes on Page 4 of 4) Page 2 of 4
I I I I I I I ITable 3-1A
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potentially Applicable Sediment Remedial Technologies1
(cont'd.)
DRAFT
General Response Action/Remedial Technology
Process Option Description Preliminary Assessment
D. Sediment Treatment (Cont'd)
IV. Extraction, Ex-Situ
V. Destruction, Ex-Situ
E. Sediment Removal
I. Dredging
II. Excavation(in-the-dry)
30CO
roro-P-
Soil Washing
Thermal Desorption
Incineration
Mechanical2
Hydraulic
Pneumatic
Amphibious
Mechanical
Water with surfactants, cosolvents or alkali used to "wash" PAHs from solids.
Similar to incineration, but typically at a lower temperature.
Sediment thermally treated in a fluidized bed, rotary kiln, or infrared incinerator, that wouldrequire permitting.
Not feasible in submergedsediment.
Potentially implementable.
Potentially implementable.
Remove bottom sediment by directly applying mechanical force to dislodge and excavatematerials (e.g., clamshell).
Removal and transportation of bottom sediment in a liquid slurry form using hydraulic pumps(e.g., horizontal auger Soli-Flo's Eddy Pump*).
Removal of bottom sediment by compressed air (e.g., PNEUMA pump).
Removal of bottom sediment through mechanical, hydraulic or pneumatic means viaspecialized amphibious dredging equipment (e.g., Aquarius-Smalley*, Amphibex).
Temporary structures (e.g., cofferdams) used to create "dry" areas in the River to allow use ofstandard excavation equipment.
Implementable.
Potentially mplementable insome areas.
Not feasible in areas withlimited water depth.
Potentially implementable indifficult-to-access areas withlimited water depth.
Potentially implementable.
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Table 3-1A DRAFT
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potentially Applicable Sediment Remedial Technologies1
(cont'd.)
General Response Action/Remedial Technology
F. Sediment Dewatering
I. Stabilization/Bulking
G. Sediment Disposal
I. On-Site Disposal
Process Option
Solidification/Stabilization
Bulking
On-Site Landfill
Description
Addition of a pozzlan material to reduce water content.
Addition of a bulking agent (e.g., saw dust) to reduce water content.
Sediment or residuals placed in on-site disposal facility that would be constructed.
Preliminary Assessment
Potentially implementable.
Potentialy implementable.
Potentially implementable perRCRA.
Notes:1 This screening analysis is based upon technical implementability without consideration of cost or particular Site issues. Shaded process options have been screened from further analysis.2 Process option was tested at bench- or pilot-scale level or investigated as part of the ASRI activities.
30CO
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W2W99F:\USERS\LR\LAR99V573TB31 A WPD Page 4 of 4
DRAFT
3DCO
rorocr»
Table 3-1B
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potential Soil Remedial Technologies1
General Response Action/Remedial Technology
Process Option Description Preliminary Assessment
A. No Action
No active remediation performed. Implementable.
B. Institutional Controls
Access restrictions
Monitoring
Deed restrictions
Constraints, such as fencing and signs, would be placed on property to limit access. Access isinherently restricted, since the site is guarded 24 hours per day.
Periodic sampling and visual observations would be used to monitor Site conditions.
Legal constraints would be placed on future land use.
Implementable, alreadyinherently in place.
Implementable.
Potentially implementable.
C. In-Place Containment
I. Capping
II. Erosion Control
Engineered Capping Design of a cap comprising layers of materials (e.g., clean soil, clay, sand, gravel, geotextile,! asphalt, concrete) placed over in-situ soil to isolate constituents and prevent direct contact withsoil and erosion.
Erosion Control Placement of vegetation or rip-rap material to increase the stability and decrease the erosionpotential of soil areas prone to erosion.
Potentially implementable.
Potentially implementable.
D. Soil Treatment
I. Biodegradation Natural
Enhanced
Naturally occurring PAH degradation by microorganisms present at the Site in an aerobicanaerobic environment.
Addition of nutrients (e.g., oxygen, minerals, etc.) or cultured microorganisms to the soil tofacilitate or improve the rate of natural biodegradation.
Potentially implementable.
Potentially implementable.
912*99F:\USERS\LR\LAR99\573TB31BWPD (See Notes on Page 4 of 4) Pagel of 4
DRAFT
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— i
Table 3-1B
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potential Soil Remedial Technologies1
(Cont'd)
General Response Action/Remedial Technology
Process Option Description Preliminary Assessment
D. Soil Treatment (Cont'd)
II. Immobilization, In-Situ Stabilization/Solidification
Vitrification
Chemically immobilize materials by injecting and mixing a stabilization/solidification agent intothe soil.
Stabilizes or destroys constituents by melting soil utilizing electrical currents. The meltedmaterial then solidifies to form a glass-like monolith.
Potentially implementable.
This process is not feasibleas a means of immobilizingorganics.
III. Extraction, In-Situ Vacuum Create vacuum in soil to draw in, and extract chemical constituents. Not feasible for creosote.
Steam Inject steam into soil so that chemical constituents volatilize and are removed. Not feasible for creosote.
In-Situ Thermal Desorption Surficial PAHs are vaporized by applying heat to the in-situ soil under a thermal blanket. PAHsthen are drawn out of the soil by a vacuum system, thermally oxidized and the air stream passedthrough granular activated carbon.
IV. Extraction, Ex-Situ Basic Extractive SludgeTreatment (BEST™)
Solvent (having inverse miscibility in water) used to remove chemicals from solids.
No full-scale application hasbeen completed.
This process has not beendemonstrated at full scale.
Low Energy ExtractionProcess (LEEP)
Acetone and kerosene used as solvents to extract chemicals from solids. This process has not beendemonstrated at full scale.
CF Systems* SolventExtraction Process
Critical fluids and liquefied gases such as carbon dioxide, propane, or other liquid hydrocarbonsused at high pressure to separate and extract organics from soil. „•
Accurex Solvent Wash A proprietary Fluorocarbon-113 and methanol solvent used to extract organics from solids.
This process has not beendemonstrated at full scale.
This process is still beingdeveloped; no full-scaleoperation.
amrxF:\USERS\LR\LAR99\573TB31BWPD (See Notes on Page 4 of 4) Page 2 of 4
Table 3-1 B
DRAFT
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potential Soil Remedial Technologies1
(Cont'd)
General Response Action/Remedial Technology Process Option Description Preliminary Assessment
D. Soil Treatment (Cont'd)
IV. Extraction, Ex-Situ (Cont'd)
V. Destruction, Ex-Situ
E. Soil Removal
I. Excavation
Methanol Extraction
Terra Kleen Solvent Extraction
Soil Washing
Biotherm (formerCarver-Greenfield) Process
Methanol used as a solvent to extract organics from solids.
Solvent used to extract organics from soil. The solvent is separated from the materials andreused.
Water with surfactants (optional) used to "wash" PAHs from solids.
Oil-soluble organic constituents extracted from soil using a food-grade carrier oil.
The process has not beendeveloped at full scale.
This process has not beendemonstrated at full scale.
Limited effectiveness forPAHs.
This process has not beendemonstrated at full scale.
THERMAL DESTRUCTION
a. Incineration
b. Low-Temperature ThermalDcsorption
Soil thermally treated in a fluidized bed, rotary kiln, or infrared incinerator, that would requireRCRA permitting.
Similar to incineration, but typically at a lower temperature.
Potentially implementable.
Potentially implementable.
Mechanical1 "" "" - - - -
j Soil removal through the use of standard excavation equipment. Potentially implementable.
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9/29/99F:\USERSMR\LAR99\573TB31B WPD (See Notes on Page 4 of 4) Page 3 of 4
DRAFT
Table 3-1B
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potential Soil Remedial Technologies1
(Cont'd)
General Response Action/Remedial Technology Process Option Description Preliminary Assessment
F. Soil Disposal
I. On-Site Disposal On-Site Landfill Disposal of soil in an on-site landfill. Potentially implementablepending approval as aCAMU.
Notes:I This screening analysis is based upon technical implementability without consideration of cost or particular Site issues. Shaded process options have been screened from further analyses.
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DRAFT
Table 3-1C
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potential Groundwater Remedial Technologies1
General Response Action/Remedial Technology Process Option Description Preliminary Assessment
A. No Action
No remedial activities performed. Implementable.
B. Institutional Controls
C. Groundwater Control
I. Groundwater Injection
II. Groundwater Removal
Deed Restrictions
Monitoring
Injection Wells
Extraction Wells
Collection Trenches
Deed restrictions may be placed to restrict usage of facility groundwater.
Groundwater monitoring typically is conducted to monitor the natural attenuation of chemicalsof interest and potential plume migration.
Implementable.
Potentially implementable.
Groundwater injection methods used to provide hydraulic control of the potential ground-waterplume movement and size.
A series of groundwater extraction wells are used to remove groundwater and/or mobilesubsurface NAPL.
Installation of perforated pipe in excavated groundwater collection trenches backfilled withporous material.
Not readily implementable.Subsurface conditions are notreadily conducive to injectionmethods due to relatively lowpermeability.
Potentially implementable.
Potentially implementable.
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VXfMF:\USERS\LR\LAR90tS73TB31 C. WPD
(See Notes on Page 2 of 2) Page 1 of 2
1 1 1 1 ( 1 1 1Table 3-1C
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Preliminary Screening of Potential Ground-Water Remedial Technologies1
(Cont'd)
DRAFT
General Response Action/Remedial Technology Process Option Description Preliminary Assessment
D. Groundwater Treatment
I. In-Situ Treatment Natural Attenuation
Enhanced Natural Attenuation
Natural attenuation occurs due to the inherent ability of the groundwater system to lower PAHconcentrations through ongoing natural, physical, chemical, and biological processes.
Addition of nutrients (e.g., oxygen, minerals) or cultured microorganisms to groundwater toimprove the rate of natural biodegradation. '
Implementable.
Potentially implementable.
II. Ex-Situ Treatment Groundwater Treatment Extracted groundwater is treated (e.g., activated carbon adsorption, filtration) to effectivelyremove PAHs from the liquid stream.
Potentially implementable.
Notes:
1. This screening analysis is based upon technical implementability without consideration of costs or particular site issues. Shaded process options have been screened from further analysis.
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F:\USEF:\USERS\LR\LAR9W73TB31 C. WPOPaqe 2 of 2
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Table 4-1
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY REPORT
Potential Impacts of Remedial Alternative 1 on Ecological and Cultural Characteristics
Areas Potentially Subject to Remediation
CharacteristicHabitat type
Habitat quality
Plant communitystatus
Wildlife speciesdiversity
Ecologicalimportance/function
Hershey RunNo change
No change
No change
No change
No change
Fire PondNo change
No change
No change
No change
No change
South Ponds AreaNo change
No change
No change
No change
No change
KAreaNo change
No change
No change
No change
No change
Upland AreasNo change
No change
No change
No change
No change
Landscape/ No changeregionalimportance
Significant No changearchaeologicaland culturalresources
No change
No change
No change
No change
No change
No change
No change
No change
Potential May persist until natural May persist until natural May persist until natural May persist until natural Natural recoveryecological risk recovery processes further recovery processes further recovery processes further recovery processes further processes expected to beafter alternative reduce potential exposure reduce potential exposure reduce potential exposure reduce potential exposure slow in further reducingimplementation ,. potential exposure.
5T3I>>I
DRAFT
Table 4-2
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Potential Impacts of Remedial Alternative 2 on Ecological and Cultural Characteristics
Areas Potentially Subject to Remediation
r»3DCO
CharacteristicHabitat type
Habitat quality
Plant communitystatus
Wildlife speciesdiversity
Ecologicalimportance/function
Landscape/regionalimportance
Significantarchaeologicaland culturalresources
Potentialecological riskafter alternativeimplementation
Hershey RunNo change
No change
No change
No change
No change
No change
No change
May persist until naturalrecovery processesfurther reduce potentialexposure.
Fire PondNo change
No change
No change
No change
No change
No change
No change
May persist until naturalrecovery processesfurther reduce potentialexposure.
South Ponds AreaNo change
No change
No change
No change
No change
No change
No change
May persist until naturalrecovery processesfurther reduce potentialexposure.
KAreaNo change
No change
No change
No change
No change
No change
No change
May persist until naturalrecovery processesfurther reduce potentialexposure.
Upland AreasNo change
No change
No change
No change
No change
No change
No change
Natural recoveryprocesses expected to beslow in further reducingpotential exposure
*rPOCOCO
373tbl
Table 4-3
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Potential Impacts off Remedial Alternative 3 on Ecological and Cultural Characteristics
DRAFT
Areas Potentially Subject to RemediationCharacteristicHabitat type
Hershey RunNo change
Fire PondNo change
South Ponds AreaNo change
KAreaTemporary reversion to
Upland AreasTemporary reversion to
Habitat quality No change
Plant community No changestatus
Wildlife species No changediversity
earlier successionalstage
earlier successional stage
Expected to improvefollowing sedimentcontainment
Expected to improvefollowing sedimentcontainment
Temporary decrease until Temporary decrease untilrevegetation is complete revegetation is complete
Plant community diversity Plant community diversitymay increase following may increase followingrecolonization recolonization
Revegetation may resultin a different plantspecies assemblage
Revegetation may result ina different plant speciesassemblage
Recolonization isexpected
Recolonization is expected Temporary decrease until Temporary decrease untilrevegetation is complete revegetation is complete
x»3DCO
•T-roCO•T"
Ecologicalimportance/function
Landscape/regionalimportance
Significantarchaeologicaland culturalresources
Potentialecological riskafter alternativeimplementation
No change
No change
No change
May persist until naturalrecovery processesfurther reduce potentialexposure
Ecological functions willincrease over time
No change
No change
None
Ecological functions willincrease over time
No change
No change
None
Ecological functions willincrease over time
No change
Potential disturbancedepending on areasremediated
None
Ecological functions willincrease over time
No change
Potential disturbancedepending on areasremediated.
None
573HV
DRAFT
Table 4-4
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Potential Impacts of Remedial Alternative 4 on Ecological and Cultural Characteristics
Areas Potentially Subject to RemediationCharacteristic Hershey Run Fire Pond South Ponds Area KArea Upland AreasHabitat type
Habitat quality
Destruction/conversion ofsome channel and marshhabitat
Temporary decrease untilrecolonization is complete
Plant community Temporarily disturbed, withstatus potential invasion of
nuisance species
Wildlife speciesdiversity
Ecologicalimportance/function
Temporary decrease untilrecolonization is complete
Potentially enhanced ifengineering controls areincorporated into design
Pond habitat eliminated;upland created
Conversion of aquatichabitat to terrestrialhabitat
Pond area habitatmodified; upland created
Minimal change due tolow quality of currenthabitat
Loss of wetland species Revegetation withand revegetation with terrestrial speciesterrestrial species
Temporary decrease due No changeto decrease in habitatquality
Loss of potential habitat Minimal change due tofor spawning amphibians; low quality of currentecological functions will habitatincrease over time
Temporary reversion to Temporary reversion toearlier successional stage earlier successional
stage
Temporary decrease until Temporary decrease untilrevegetation is complete revegetation is complete
Revegetation may result Revegetation may resultin a different plant species in a different plantassemblage species assemblage
Temporary decrease until Temporary decrease untilrevegetation is complete revegetation is complete
Ecological functions willincrease over time
Ecological functions willincrease over time
3DCO
COc/i
Landscape/regionalimportance
Significantarchaeologicaland culturalresources
Potentialecological riskafter alternativeimplementation
Remediation would cause No change No changeloss or degradation ofwetland habitat
No change No change No change
Exposure to CoPCs is None Noneeliminated
No change
Potential disturbancedepending on areasremediated
None
No change
Potential disturbancedepending on areasremediated
None
S73W
DRAFT
Table 4-5
FORMER KOPPERS COMPANY, INC. NEWPORT SITEFEASIBILITY STUDY
Potential Impacts of Remedial Alternative 5 on Ecological and Cultural Characteristics
3DCO
roCOen
Areas Potentially Subject to RemediationCharacteristicHabitat type
Habitat quality
Plant communitystatus
Wildlife speciesdiversity
Ecologicalimportance/function
Landscape/regionalimportance
Significantarchaeologicaland culturalresources
Potentialecological riskafter alternativeimplementation
Hershey RunDestruction of channeland marsh habitat
Temporary decrease dueto mechanical effects ofdredging
Removed, with potentialinvasion of nuisancespecies
Temporary decreasedremediated areas anddownstream areas due tohabitat modification
Diminished; ecologicalfunctions will increaseover time
Remediation wouldcause loss ordegradation of wetlandhabitat
No change
Increased due to theresidual impacts ofdredging
Fire PondPond habitat eliminated;upland created
Conversion of aquatichabitat to terrestrialhabitat
Loss of wetland speciesand revegetation withterrestrial species
Temporary decrease dueto decrease in habitatquality
Loss of potential habitatfor spawning amphibians;ecological functions willincrease over time
No change
No change
None
South Ponds AreaPond area habitatmodified; upland created
Minimal change due tolow quality of currenthabitat
Revegetation withterrestrial species
No change
Minimal change due tolow quality of currenthabitat
No change
No change
None
KAreaTemporary reversion toearlier successionalstage
Temporary decrease untilrevegetation is complete
Revegetation may resultin a different plantspecies assemblage
Temporary decrease untilrevegetation is complete
Ecological functions willincrease over time
No change
Potential disturbancedepending on areasremediated
None
Upland AreasTemporary reversion toearlier successionalstage
Temporary decrease untilrevegetation is complete
Revegetation may resultin a different plantspecies assemblage
Temporary decrease untilrevegetation is complete
Ecological functions willincrease over time
No change
Potential disturbancedepending on areasremediated
None
>Ct)GO8t
ItemLNone
SUBTOTAL15% ENGINEERING & SUPPORT20% CONTINGENCY
Table 4-6
Alternative 1 - No Action
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
Quantity Units
$0$0$0
Convnonts
TOTALROUNDED TOTAL
$0$0
Annual (Operation & Maintenance) CostItem
1 . None
SUBTOTAL15% ENGINEERING & SUPPORT20% CONTINGENCY
Quantity Units | umtcost(i) 1 Item Cost 1 comments
$0$0$0
TOTAL $0ROUNDED TOTAL $0
Thirty-Year Present Worth Cost $0
A R 3 U 2 3 7Paae 1 of 1 30-Sep-99
Table 4-7
Alternative 2 - Monitored Natural Attenuation, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
f
Capital (Direct and Indirect) Cost . .; • Item
1. Deed Restrictions
2. Installation of Warning Signs
3. NAPL Recovery (3)
SUBTOTAL15% ENGINEERING & SUPPORT(11)20% CONTINGENCY(12)
Quantity
1
30
1
Units -
lump sum
each
lump sum
iiffl.'KTirf iwi • inrram • •• • • •fnTTTTi BBBla^HB$10,000
$45
$65.000
$10,000
$1 ,350
$65,000
$76,350$11,453$15,270
Assumes cost for legal and applicationfees for deed restrictions to limit futureland use and construction activities for theUpland Areas and prohibit use ofgroundwater as a water supply source.
Assumes placement of warning signs at500-foot intervals along perimeter of site.
Assumes installation of pilot scale NAPLrecovery within wells MW-2A and MW-8A.
TOTAL: $103.073ROUNDED TOTAL $103,000
^nnuaT75pera5Sn a Maintenance) Costri item
1 . Site Access Maintenance
2. NAPL System Maintenance(4)a. NAPL Recovery
b. NAPL Disposal
3. Groundwater Monitoring(S)a. Groundwater Sampling(6)
b. Analytical(7)
c. Direct Expenses(S)d. Data Evaluation/Reporting ,
4. Biota Monrtoring(9)a. Benthic Survey(10)
b. Fish Sampling(10) s
c. Analyticald. Direct Expenses(S)e. Data Evaluation/Reporting
SUBTOTAL15% ENGINEERING & SUPPORT(11)20% CONTINGENCY(12)
Quantity
1
12
1
10
1
11
6
15
4011
Units | Unit Cost(1 ,2) I Item Cost
lump sum
month
drum
manday
event
lump sumlump sum
manday
manday
samplelump sumlump sum
$10.000
$1,200
$1,000
$520
$16,500
$3,700$10,000
$1,000
$1,000
$300$3,700
$16,000
$10,000
$14,400
$1,000
$5,200
$16,500
$3,700$10,000
$6,000
$15,000
$12,000$3,700
$16,000
$113,500$17,025$22,700
Comments
Assumes weekly site inspections andannual repairs to site fencing and signs.
Assumes one technician two days permonth to perform NAPL recovery.
Assumes one 55 gallon drum of NAPL peryear. Cost for transportation andincineration of drummed liquid waste.
Assumes cost for two field technicians for5 days to collect groundwater samplesand monitor for NAPL from 30 monitoringwells per event.
Thirty samples plus QA/QC per event forPAHs and natural attenuation parameters.
Assumes cost for two scientists for 3 days.
Assumes cost for three scientists for 5days.
TOTAL: $153,225ROUNDED TOTAL: $1 53,000
A R 3 I k 2 3 8Pane 1 of 2 30-Sep-99
Table 4-7
Alternative 2 - Monitored Natural Attenuation. Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
osmThirty-Year Present Worth Cost(13): $2.41 MBHon
General Notes and Assumptions—r. Unit cost shown includes material and labor, unless otherwise noted.
2. Unit cost from Means 1999, unless otherwise noted."•. Cost provided by contractor for similar Blasland, Bouck & Lee, Inc. project.. NAPL recovery assumed to be complete after five years of system operation. System operation will be evaluated at the end of five year service life.
-9. Groundwater monitoring will include the sampling of groundwater and monitoring of NAPL from within 30 existing monitoring wells. Groundwatermonitoring will be performed quarterly for the first year, semi-annual for the second year, and once per year thereafter.
~. Unit cost assumes labor rate of $65/hour for an eight hour day (Blasland, Bouck & Lee, Inc. senior field technician rate).. Laboratory analytical cost includes analysis for PAHs. Additional analytical parameters to facilitate the monitoring of natural attenuation indude; dissolved
— oxygen, oxidation-reduction potential, ferric/ferrous iron, nitrate/nitrite, and surfate/surfite.8. Direct expenses consist of sampling equipment and subsistence (meals, lodging, vehicle).. Biota monitoring will include the performance of a benthic survey at 3-5 locations with the collection of five samples per location. Biota monitoring will
also include the collection of two species of fish samples from two locations with the analysis of ten samples per species."TO. Unit cost assumes a labor rate of $100/hour for a ten hour day (Blasland, Bouck & Lee, Inc. senior scientist rate).11. A 15 percent contingency for Engineering & Support cost includes, but is not limited to the following: administration and supervision, design and
development, monitoring and testing, and cost estimating. Engineering & Support cost does not include legal fees and permit acquisition. Engineering &Support cost developed based upon EPA 600/8-87/049 "Remedial Action Costing Procedures Manual* (1987).
"T5. A 20 percent contingency allowance is included to provide for unforseen circumstances or variability in estimated areas, volumes, and labor and materialcosts. Contingency allowance developed based upon EPA 600/8-87/049 "Remedial Action Costing Procedures Manual" (1987).Present worth cost is based on a total capital (direct and indirect) expenditure (taken in the first year) and annual (operation and maintenance) costs taken
__ over a 30-year time frame at a discount rate of five percent per EPA Guidance (EPA/540/G-89/004).
A R 3 U 2 3 9IMUTIPDFP<;t1<wlQAI TO X/W) Paoe2of2 30-Sep-99
Table 4-8
Alternative 3 - Upland Surface Soil Removal, Upland Sediment Containment, On-Site Disposal,Monitored Natural Attenuation, Institutional Controls, and Pilot Study C
Former Koppers Company, Inc. - Newport Site BFeasibility Study
Preliminary Cost Estimate
AFT
^^^f^ltoni • " • • • • • • • ; • • : : : ••1 . Mobilization/Demobilization2. Site Preparation
a. Clear & Grub Dense Brush
b. Equipment Decontamination Area
c. Silt Fencing
d. Access Roads
e. Drainage Culverts
3. Archaeological Evaluation
4. Cap/Cover Fire Pond Area (4 acres)
5. Cap/Cover South Pond Area (1 .5 acres)
6. Fill K Area (0.5 acres)a. Backfill, Grading & Compaction
b. Topsoil
c. Vegetative Cover
7. Surface Soil Removal (Upland Area)a. Excavation and On-Site Transportation
b. Grading and Compaction in On-Site Landfill
c. Backfill Surface Soil Excavation Area
8. Surface soil Removal (Loading Dock Area)a. Excavation and On-Site transportation
b. Grading and Compaction in On-Site Landfill
c. Backfill Surface Soil Excavation Area
Quantity1
26.0
1.0
24,000
6,000
10
1.0
6.450
2,420
3.200
400
0.5
30.000
30,000
30.000
10,000
10,000
10,000
Units
lump sum
acre
lump sum
linear feet
linear feet
each
lump sum
cubic yard
cubic yard
cubic yard
cubic yard
acre
cubic yard
cubic yard
cubic yard
cubic yard
cubic yard
cubic yard
lUnltCo l tfrngSn5%
$600
$23,000
$1.00
$23.00
$1,000
$300.000
$10.00
$10.00
$10.00
$22.00
$3,500
$7.25
$3.00
$10.00
$7.25
$3.00
$10.00
$193,429
$15,600
$23,000
$24,000
$138.000
$10,000
$300,000
$64,500
$24,200
$32,000
$8,800
$1,750
$217,500
$90,000
$300,000
$72,500
$30,000
$100,000
COflMMItlA •i.-.Sfti-t**?- J-;4*
Five percent of items 2 through 1 1 .
Assumes clear & grub of Fire Pond, SouthPond, K Area, and Upland Areas.
Assumes 20' x 40' concrete slab, sump,collection tank, pressure washer, andpiping.
Assumes silt fence placed alongperimeter of excavation areas and alongeach side of access roadways.
Assumes 12 feet wide, geotextile fabric,12-inch crushed stone layer, grading andcompaction for access roads to Fire Pond,South Pond, K Area, and Upland Areas.
Assumes placement of 12" diameterCMP, tapered end pieces, bank run fill,and rip-rap at approximately 10 locationsalong access roadways.
Assumes performance of Phase IIarchaeological evaluations and Phase IIIdata recovery excavations for areasimpacted by construction activities.
Assumes 1 ft of cap/cover materialrequired within the 4 acre Fire Pond Area.
Assumes 1 ft of cap/cover materialrequired within the 1 .5 acre South PondArea.
Assumes 4 ft of fill required within the 0.5acre K Area.
Assumes placement of 6" of topsoil overthe 0.5 acre area.
Cost includes vegetative cover and strawmulch.
Cost includes excavation of surface soilareas and transportation to On-SiteLandfill.
Cost includes grading and compaction ofmaterials within On-Site Landfill.
Assumes backfill quantities are equal tosoil excavation volumes.
Cost includes excavation of surface soilareas and transportation to On-SiteLandfill.Cost includes grading and compaction ofmaterials within On-Site Landfill.
Assumes backfill quantities are equal tosoil excavation volumes.
AR3 11*21*0Paae 1 of 4 30-Sep-99
Table 4-8
Alternative 3 - Upland Surface Soil Removal, Upland Sediment Containment, On-Site Disposal,Monitored Natural Attenuation, Institutional Controls, and Pilot Study
Former Koppers Company. Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
Capital (Direct anfl indirect) ••*&&$• rTzr.r,^ ••?•?-*••* «• Item
9. Construct On-Site Landfill
a. Excavation
b. Sand Filter Layerc. Gravel Drainage Layerd. VLDPE Linere. Gravel Drainage Layerf. VLDPE Linerg. Clay Layerh. Leachate Collection System
10. Construct On-Site Landfill
a. Vegetative Coverb. Topsoil Layerc. Geotextiled. Gravel Drainage Layere. VLDPE Linerf. Clay Layerg. Monitoring Wells
h. Perimeter Access Road
i. Perimeter Fence
11. NAPL Recovery (3)
SUBTOTAL15% ENGINEERING & SUPPORT(11)20% CONTINGENCY(12)
Quantity
9,100
4,7005,100
143.0005,500
154,00018.900
1
6.016,70025.1007,900
212,50014.100
4
2,000
2.100
1
Units I Unit Cost(1, 2)| item cost
cubic yard
cubic yardcubic yardsquare feetcubic yardsquare feetcubic yardlump sum
acrecubic yard
square yardcubic yardsquare feetcubic yard
well
linear feet
linear feet
lump sum
$4.00
$14.00$25.00$1.00
$25.00$1.00
$16.00$200.000
$3.500$22.00
$1.85$25.00$1.00
$16.00$3,000
$23.00
$27
$65,000
$36,400
$65,800$127,500$143,000$137,500$154,000$302,400$200,000
$21,000$367.400
$46,435$197,500$212,500$225,600$12,000
$46,000
$56.700
$65,000
$4,062,014$609,302$812,403
conrnentA^n^,':. ,* •--•• -.<•Assumes a capacity of approximately40,000 cubic yards.
Assumes excavation of materials toobtain bottom slope of approximately 3%.
Assumes 12-inch thickness.Assumes 12-inch thickness.Assumes 30-mil thickness.Assumes 12-inch thickness.Assumes 30-mil thickness.Assumes 3-feet thickness.Piping.Assumes a capacity of approximately40,000 cubic yards.
Assumes seeding and straw mulch.Assumes 2-feet thickness.
Assumes 12-inch thickness.Assumes 30-mil thickness.Assumes 2-feet thickness.Assumes installation of one upgradiendand three downgradient monitoring wellswith average depth of 20 feet.
Assumes 12 feet wide, geotextile fabric,12-inch crushed stone layer, grading andcompaction for access road aroundperimeter of On-Site Landfill Area.
Assumes 7' chain-link fence aroundperimeter of On-Site Landfill Area.
Assumes installation of pilot scale NAPLrecovery within wells MW-2A and MW-8A.
TOTAL $5.483,719ROUNDED TOTAL: $5,484.000
A R 3 | l * 2 i * lPaae 2 of 4 30-Sep-99
Table 4-8
Alternative 3 - Upland Surface Soil Removal, Upland Sediment Containment, On-Site Disposal,Monitored Natural Attenuation, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
TAnnual (Operations Maintenance) Cost
item • : •1 . Site Access Maintenance
2. NAPL System Maintenance )a. NAPL Recovery
b. NAPL Disposal
3. On-Site Landfill Maintenancea. Mowing
b. Repairs
c. Leachate Disposal
4. Groundwater Monitoring(S)a. Groundwater Sampling(6)
b. Analytical(7)
c. Direct Expenses(S)d. Data Evaluation/Reporting
5. Sediment Deposition Monitoringa. Sediment Traps
b. Direct Expenses6. Biota Monitoring(9)
a. Benthic Survey (10)b. FishSampling(IO)
c. Analyticald. Direct Expenses(8)e. Data Evaluation/Reporting /
SUBTOTAL15% ENGINEERING & SU^PORT(1 1)20% CONTINGENCY(12)
. " . : . .
• Quantity1
12
1
6
1
10,000
12
1
11
10
1
615
4011
units
lump sum
month
drum
event
lump sum
gallon
manday
event
lump sumlump sum
manday
lump sum
mandaymanday
samplelump sumlump sum
110110081(1,2)
$10,000
$1,200
$1.000
$700
$1,000
$1.75
$520
$18,500
$3.700$10,000
$520
$2,000
$1,000$1,000
$300$3,700
$16,000
- -. - - * , .- ..item cost
$10,000
$14,400
$1,000
$4,200
$1,000
$17,500
$6,240
$18,500
$3,700$10,000
$5,200
$2,000
$6,000$15,000
$12,000$3.700
$16,000
$146.440$21,966$29,288
Comments -^.Assumes weekly site inspections andannual repairs to site fencing and signs.
Assumes one technician two days permonth to perform NAPL recovery.
Assumes one 55 gallon drum of NAPL peryear. Cost for transportation andincineration of drummed liquid waste.
Assumes mowing of approximately sixacre area. Assumes six events annually.
Assumes hand placement of 10 cubicyards of topsoil to repair erosion.
Assumes bulk liquid, non-hazardousdisposal.
Assumes cost for two field technicians for5 days to collect groundwater samplesand monitor for NAPL from 30 monitoringwells per event. Assumes one additionalday for On-Site Landfill monitoring wellsample collection.
Thirty samples plus QA/QC per event forPAHs and natural attenuation parameters.Four additional samples for On-SiteLandfill monitoring.
Assumes semi-annual sediment depthmonitoring at 10 locations. Cost for twofield technicians for 5 days.
Assumes cost for two scientists for 3 days.Assumes cost for three scientists for 5days.
TOTAL: $197,694ROUNDED TOTAL: $1 98,000
Thirty-Year Present Worth Cost(13) $8.49 Million
Page 3 of 4 30-Sep-99
— Table 4-«
Alternative 3 - Upland Surface Soil Removal, Upland Sediment Containment, On-SiteMonitored Natural Attenuation, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
~" Preliminary Cost EstimateGeneral Notes and AssumptionsUnit cost shown includes material and labor, unless otherwise noted.Unit cost from Means 1999, unless otherwise noted.
"7. Cost provided by contractor for similar Blasland, Bouck & Lee, Inc. project.4. NAPL recovery assumed to be complete after five years of system operation. System operation will be evaluated at the end of five year service life.
Groundwater monitoring will include the sampling of groundwater and monitoring of NAPL from within 30 existing monitoring wells. Groundwatermonitoring will be performed quarterly for the first year, semi-annual for the second year, and once per year thereafter.
~6. Unit cost assumes labor rate of $65/hour for an eight hour day (Blasland, Bouck & Lee, Inc. senior field technician rate).7. Laboratory analytical cost includes analysis for PAHs. Additional analytical parameters to facilitate the monitoring of natural attenuation include; dissolved
oxygen, oxidation-reduction potential, ferric/ferrous iron, nitrate/nitrite, and sulfate/sulfite.^_ Direct expenses consist of sampling equipment and subsistence (meals, lodging, vehicle).9. Biota monitoring will include the performance of a benthic survey at 3-5 locations with the collection of five samples per location. Biota monitoring will
also include the collection of two species of fish samples from two locations with the analysis of ten samples per species.Unit cost assumes a labor rate of $100/hour for a ten hour day (Blasland, Bouck & Lee, Inc. senior scientist rate).
_ A 15 percent contingency for Engineering & Support cost includes, but is not limited to the following: administration and supervision, design anddevelopment, monitoring and testing, and cost estimating. Engineering & Support cost does not include legal fees and permit acquisition. Engineering &Support cost developed based upon EPA 600/8-87/049 "Remedial Action Costing Procedures Manual" (1987).A 20 percent contingency allowance is included to provide for unforseen circumstances or variability in estimated areas, volumes, and labor and materialcosts. Contingency allowance developed based upon EPA 60078-87/049 "Remedial Action Costing Procedures Manual" (1987).
13. Present worth cost is based on a total capital (direct and indirect) expenditure (taken in the first year) and annual (operation and maintenance) costs takenover a 30-year time frame at a discount rate of five percent per EPA Guidance (EPA/540/G-69/004).
A R 3 l i * 2 « * 3IIVKr>PPFRS\1549ALT3WB2 Page 4 of A 30-S»p-99
Table 4-9
Alternative 4 - Hershey Run Rechannelization, Upland Surface Soil and Sediment Removal, On-Site Disposal,Monitored Natural Attenuation, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
H A F TCapital (Direct add Indirect) -• - -• ; -
M Item1 . Mobilization/Demobilization2. Site Preparation
a. Clear & Grub Dense Brush
b. Equipment Decontamination Area
c. Silt Fencing
d. Access Roads
e. Access Roads (Hershey Run)
f. Drainage Culverts
3. Archaeological Evaluation
4. Rechannel Hershey Runa. Excavation & Transportation to Staging
b. Rip-rap and restore new channel
5. Fill Existing Hershey Runa. Backfill using staged materials
Nc. Backfill, Grading & Compaction
c. Vegetative Cover
Quantity1
26.0
1.0
39.000
7,600
6,400
15
1.0
18,000
6,000
18,000
28,000
6
•^•'Ll ••I'1, I* ifilaWi ..I' ••• • • •jpi' 'i. ..' |i MHIPMMBlump sum
acre
lump sum
linear feet
linear feet
linear feet
each
lump sum
cubic yard
cubic yard
cubic yard
cubic yard
acre
5%
$600
$23.000
$1.00
$23.00
$41.00
$1.000
$700,000
$13.00
$40.00
$8.00
$10.00
$3,500
$323,589
$15,600
$23,000
$39,000
$174,800
$262,400
$15,000
$700,000
$234,000
$240,000
$144,000
$280,000
$21,000
Five percent of items 2 through 13.
Assumes clear & grub of Fire Pond, SouthPond, K Area, and Upland Areas.
Assumes 20' x 40* concrete slab, sump,collection tank, pressure washer, andpiping.Assumes silt fence placed alongperimeter of excavation areas and alongeach side of access roadways.
Assumes 12 feet wide, geotextile fabric.12-inch crushed stone layer, grading andcompaction for access roads to Fire Pond,South Pond, K Area, and Upland Areasand access to Hershey Run.
Assumes 1 2 feet wide, two layers ofgeotextile fabric, 24-inch gravel layer, and12-inch crushed stone layer, grading andcompaction for access roads to low lyingareas along existing Hershey Run andrechannelized Hershey Run.
Assumes placement of 1 2" diameterCMP, tapered end pieces, bank run fill,and rip-rap at approximately 1 5 locationsalong access roadways.
Assumes performance of Phase IIarchaeological evaluations and Phase IIIdata recovery excavations for areasimpacted by construction activities.
Assumes excavation of new channel withaverage width of 50-feet and depth of6-feet.
Assumes placement of rip-rap (18-inchthick) along 2,000 linear feet ofrechannelized Hershey Run.
Assumes backfill of Hershey Run partiallyperformed using on-site staged materialfrom re-channelization. Total volume ofmaterial required to backfill existingHershey Run =46,000 cubic yards. Costincludes loading and transportation fromstaging area, grading and compaction.
Assumes backfill of Hershey Run usingoff-site source of borrow material tosubsidize total fill volume (46,000 cubicyards) required for backfill of HersheyRun.
Cost includes seeding and straw mulch tore-establish vegetative cover.
U AKOPPERSM 549ALT4 WB2 Page 1 of 5
AR3 l l *2 l * l *30-Sep-99
Table 4-9
Alternative 4 - Hershey Run Rechannelization, Upland Surface Soil and Sediment Removal, On-Site Disposal,Monitored Natural Attenuation, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost EstimateI
Capital (Direct and Indirect)Item
6. Sediment Removal (Fire Pond)a. Dewater Pond Area
b. Excavation and transportation to On-Site Lac. Grading and Compaction in On-Site Landfill
d. Backfill, Grading & Compaction
e. Topsoil
f. Vegetative Cover
7. Sediment Removal (South Pond)a. Dewater Pond Area
b. Excavation and On-Site Transportationc. Grading and Compaction in On-Site Landfill
d. Backfill, Grading & Compaction
e. Topsoil
f. Vegetative Cover
8. Soil Removal (K Area)a. Excavation and On-Site Transportationb. Grading and Compaction in On-Site Landfill
c. Backfill, Grading & Compaction
d. Topsoils
e. Vegetative Cover
9. Surface Soil Removal (Upland Area)a. Excavation and On-Site Transportation
b. Grading and Compaction in On-Site Landfill
c. Backfill surface soil excavation area
Quantity
1,300,000
3,5003.500
13,000
3.200
4
500,000
4,0004,000
11,300
1,200
2
100100
3,300
400
0.5
30,000
30,000
30,000
gallon
cubic yardcubic yard
cubic yard
cubic yard
acre
gallon
cubic yardcubic yard
cubic yard
cubic yard
acre
cubic yardcubic yard
cubic yard
cubic yard
acre
cubic yard
cubic yard
cubic yard
$0.10
$7.25$3.00
$10.00
$22.00
$3,500
$0.10
$7.25$3.00
$10.00
$22.00
$3,500
$7.25$3.00
$10.00
$22.00
$3.500
$7.25
$3.00
$10.00
$130,000
$25,375$10.500
$130,000
$70,400
$14,000
$50,000
$29,000$12,000
$113,000
$26,400
$5,250
$725$300
$33,000
$8,800
$1,750
$217,500
$90,000
$300,000
Assumes removal of surface water withestimated depth of 1-feet from 4 acrepond area. Assumes on-site treatmentthrough carbon (disposable GAC units)with on-site discharge.
Cost includes grading and compaction ofmaterials within On-Site Landfill.
Assumes replacement of excavated soils,plus additional 4 ft of fill required withinthe Fire Pond and 1 ft of fill placed overthe 4 acre area for hydraulicimprovements.
Assumes placement of 6" of topsoil overthe 4 acre area.
Cost includes seeding and straw mulch tore-establish vegetative cover.
Assumes removal of surface water withestimated depth of 1-feet from 1 .5 acrepond area. Assumes on-site treatmentthrough carbon (disposable GAC units)with on-site discharge.
Cost includes grading and compaction ofmaterials within On-Site Landfill.
Assumes replacement of excavated soils,plus additional 3 ft of fill required withinthe 1 .5 acre South Pond Area forhydraulic improvements.
Assumes placement of 6" of topsoil overthe 1 .5 acre area.
Cost includes seeding and straw mulch tore-establish vegetative cover.
Cost includes grading and compaction ofmaterials within On-Site Landfill.
Assumes replacement of excavated soils,plus additional 4 ft of fill required withinthe 0.5 acre K Area for hydraulicimprovements.Assumes placement of 6" of topsoil overthe 0.5 acre area.
Cost includes seeding and straw mulch tore-establish vegetative cover.
Cost includes excavation of surface soilareas and transportation to On-SiteLandfill.
Cost includes grading and compaction ofmaterials within On-Site Landfill.
Assumes backfill quantities are equal tosoil excavation volumes.
U:\KOPPERS\1549ALT4.WB2 Page 2 of S 30-Sep-99
Table 4-9
Attemath/e 4 - Hershey Run Rechannelization, Upland Surface Soil and Sediment Removal, On-Site Disposal,Monitored Natural Attenuation, Institutional Controls, and Pilot Study
Former Koppers Company. Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
capital (Direct and indirect)Item
10. Surface soil Removal (Loading Dock Area)a. Excavation and On-Site Transportation
b. Grading and Compaction in On-Site Landfill
c. Backfill surface soil excavation area
11. Construct On-Site Landfill
a. Excavation
b. Sand Filter Layerc. Gravel Drainage Layerd. VLDPE Linere. Gravel Drainage Layerf. VLDPE Linerg. Clay Layerh. Leachate Collection System
12. Construct On-Site Landfill RCRA Cover
a. Vegetative Coverb. Topsoil Layerc. Geotextiled. Gravel Drainage Layere. VLDPE Linerf. Clay Layerg. Monitoring Wells
h. Perimeter Access Road
i. Perimeter Fence
13. NAPL Recovery (3)
SUBTOTAL N
15% ENGINEERING & SUPPORT(9)20% CONTINGENCY(IO)
Quantity
10,000
10,000
10,000
10,900
5,6006,100
172,0006,600
185.00022,700
1
7.020,00030,1009,500
255,00016,900
4
2,200
2.300
1
Units
cubic yard
cubic yard
cubic yard
cubic yard
cubic yardcubic yardsquare feetcubic yardsquare feetcubic yardlump sum
acrecubic yard
square yardcubic yardsquare feetcubic yard
well
linear feet
linear feet
lump sum
Unit Cost(1,2)
$7.25
$3.00
$10.00
$4.00
$14.00$25.00$1.00
$25.00$1.00
$16.00$220,000
$3,500$22.00$1.85
$25.00$1.00
$16.00$3,000
$23.00
$27
$65,000
item cost
$72,500
$30,000
$100,000
$43,600
$78,400$152,500$172,000$165,000$185,000$363,200$220,000
$24,500$440,000$55,685
$237,500$255,000$270,400$12,000
$50,600
$62,100
$65,000
$6,795,374$1,019,306$1,359,075
Conwvwntft
Cost includes excavation of surface soilareas and transportation to On-StteLandfill.
Cost includes grading and compaction ofmaterials within On-Site Landfill.
Assumes backfill quantities are equal tosoil excavation volumes.
Assumes a capacity of approximately50,000 cubic yards.
Assumes excavation of materials toobtain bottom slope of approximately 3%.
Assumes 1 2-inch thickness.Assumes 12-inch thickness.Assumes 30-mil thickness.Assumes 12-inch thickness.Assumes 30-mil thickness.Assumes 3-feet thickness.Piping.Assumes a capacity of approximately50,000 cubic yards. Assumes coverslope of approximately 1 5%.
Assumes seeding and straw mulch.Assumes 2-feet thickness.
Assumes 12-inch thickness.Assumes 30-mil thickness.Assumes 2-feet thickness.Assumes installation of one upgradiendand three downgradient monitoring wellswith average depth of 20 feet.
Assumes 12 feet wide, geotextile fabric,1 2-inch crushed stone layer, grading andcompaction for access road aroundperimeter of On-Site Landfill Area.
Assumes 7' chain-link fence aroundperimeter of On-Site Landfill Area.
Assumes installation of pilot scale NAPLrecovery within wells MW-2A and MW-8A.
TOTAL: $9,173,755ROUNDED TOTAL: $9, 1 74,000
U:\KOPPERSM 549ALT4 WB2 Page 3 of S
A R 3 ! l * 2 i * 630-S«p-99
Table 4-9
Alternative 4 - Hershey Run Rechannelization, Upland Surface Soil and Sediment Removal. On-Site Disposal,Monitored Natural Attenuation, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost EstimateliflFT
Annual (Operation & Maintenance) Cost• • • :: Item •• • • • •- -. '• • • • • •" "• •
1 . Site Access Maintenance
2. NAPL System Maintenance^)a. NAPL Recovery
b. NAPL Disposal
3. On-Site Landfill Maintenancea. Mowing
b. Repairs
c. Leachate Disposal
4. Groundwater Monitoring(S)a. Groundwater Sampling(6)
b. Analytical(7)
c. Direct Expenses(S)d. Data Evaluation/Reporting
SUBTOTAL15% ENGINEERING & SUPPORT(9)20% CONTINGENCY(IO)
Quantity
1
12
1
6
1
10,000
12
1
11
Units •
lump sum
month
drum
event
lump sum
gallon
manday
event
lump sumlump sum
UnKCOSt(1l2)
$10,000
$1,200
$1,000
$700
$1,000
$1.75
$520
$18,500
$3,700$10,000
Item Cost
$10,000
$14,400
$1,000
$4,200
$1,000
$17,500
$6,240
$18,500
$3,700$10,000
$86,540$12,981$17,308
- .. •Comments; :
Assumes weekly site inspections andannual repairs to site fencing and signs.
Assumes one technician two days permonth to perform NAPL recovery.
Assumes one 55 gallon drum of NAPL peryear. Cost for transportation andincineration of drummed liquid waste.
Assumes mowing of approximately sixacre area. Assumes six events annually.
Assumes hand placement of 10 cubicyards of topsoil to repair erosion.
Assumes bulk liquid, non-hazardousdisposal.
Assumes cost for two field technicians for5 days to collect groundwater samplesand monitor for NAPL from 30 monitoringwells per event. Assumes one additionalday for On-Site Landfill monitoring wellsample collection.
Thirty samples plus QA/QC per event forPAHs and natural attenuation parameters.Four additional samples for On-SiteLandfill monitoring.
TOTAL: $116,829ROUNDED TOTAL: $117,000
Thirty-Year Present Worth Cost(11) $10.92 Million
U JPPERSM549ALT4.WB2 Page 4 of 5 A R 3 l i * 2 i * 7 30-Sep-99
Table 4-9
Alternative 4 - Hershey Run Rechannelization, Upland Surface Soil and Sediment Removal, On-Site Disposal,Monitored Natural Attenuation, Institutional Controls, and Pilot Study
— Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
General Notes and Assumptions1. Unit cost shown Includes material and labor, unless otherwise noted.i. Unit cost from Means 1999, unless otherwise noted.
~3. Cost provided by contractor for similar Blasland, Bouck & Lee, Inc. project.4. NAPL recovery assumed to be complete after five years of system operation. System operation will be evaluated at the end of five year service life."5. Groundwater monitoring will include the sampling of groundwater and monitoring of NAPL from within 30 existing monitoring wells. Groundwater
monitoring will be performed quarterly for the first year, semi-annual for the second year, and once per year thereafter.6. Unit cost assumes labor rate of $65/hour for an eight hour day (Blasland, Bouck & Lee, Inc. senior field technician rate).7. Laboratory analytical cost includes analysis for PAHs. Additional analytical parameters to facilitate the monitoring of natural attenuation include; dissolved
oxygen, oxidation-reduction potential, ferric/ferrous iron, nitrate/nitrite, and surfate/suffito.3. Direct expenses consist of sampling equipment and subsistence (meals, lodging, vehicle).
~~9. A15 percent contingency for Engineering & Support cost includes, but is not limited to the following: administration and supervision, design anddevelopment, monitoring and testing, and cost estimating. Engineering & Support cost does not include legal fees and permit acquisition. Engineering &Support cost developed based upon EPA 600/8-87/049 "Remedial Action Costing Procedures Manual" (1987).
__) A 20 percent contingency allowance is included to provide for unforseen circumstances or variability in estimated areas, volumes, and labor and materialcosts. Contingency allowance developed based upon EPA 600/8-87/049 "Remedial Action Costing Procedures Manual" (1987).
11. Present worth cost is based on a total capital (direct and indirect) expenditure (taken in the first year) and annual (operation and maintenance) costs takenover a 30-year time frame at a discount rate of five percent per EPA Guidance (EPA/540/G-89/004).
A R 3 U 2 U 8OPPERSM 549ALT4.WB2 Page 5 of 5 30-Sep-99
Table 4-1OA
Alternative 5A - Hershey Run Sediment Removal, Upland Surface SoM and Sediment Removal, Off-Site Thermal Treatment (Thermal Desorption),Groundwater Recovery and Treatment, Monitoring, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate TCapital (Direct and Indirect) - -
=P»' Hem •• - - = : - i - : . . -- :.-,•.:
1. Mobilization/Demobilization2. Site Preparation
a. Clear & Grub Dense Brush
b. Equipment Decontamination Area
c. Silt Fencing
d. Access Roads
e. Access Roads (Hershey Run)
f. Drainage Culverts
3. Archaeological Evaluation
4. Temporary Sheeting (flow diversion)a. Hershey Run Sheeting
5. Sediment Excavation (Hershey Run)a. Sediment Excavation
b. Transportation to Staging/Dewatering Area
6. Sediment Excavation (West Central Drainage Areaa. Sediment Excavation
sb. Transportation to Staging/Dewatering Area
. Quantity •;
1
26.0
1.0
44,000
7,600
4,600
15
1.0
125,000
100,000
100.000
35,000
35,000
*• Unto w
lump sum
acre
lump sum
linear feet
linear feet
linear feet
each
lump sum
square feet
cubic yard
cubic yard
cubic yard
cubic yard
UnMCosK1.2)
5%
$600
$23.000
$1.00
$23.00
$41.00
$1.000
$700,000
$11.25
$21.00
$9.00
$35.00
$9.00
Item Cost
$712,301
$15,600
$23,000
$44.000
$174.800
$188,600
$15,000
$700,000
$1,406,250
$2,100,000
$900,000
$1,225,000
$315,000
Convnenis •"••-''vr^--£^v.3^8
Five percent of items 2 through 13. 15, and16.
Assumes dear & grub of Fire Pond. SouthPond, K Area, and Upland Areas.
Assumes 20' x 40' concrete slab, sump,collection tank, pressure washer, andpiping.
Assumes silt fence placed along perimeterof excavation areas and along each side ofaccess roadways.
Assumes 12 feet wide, geotextile fabric,12-inch crushed stone layer, grading andcompaction for access roads to Fire Pond,South Pond, K Area, and Upland Areasand access to Hershey Run.
Assumes 12 feet wide, two layers ofgeotextile fabric, 24-inch gravel layer, and12-inch crushed stone layer, grading andcompaction for access roads to low lyingareas along existing Hershey Run tofacilitate excavation of sediments.
Assumes placement of 12" diameter CMP,tapered end pieces, bank run fill, andrip-rap at approximately 10 locations alongaccess roadways.
Assumes performance of Phase IIarchaeological evaluations and Phase IIIdata recovery excavations for areasimpacted by construction activities.
Assumes installation and recovery of 16'vertical lengths of steel sheeting. Sheetingwill be required along the length of thecenter of Hershey Run (5,200 linear feet)for flow diversion during sedimentexcavation. Additional sheeting win beinstalled at 100' increments to separateexcavation areas from flow of water.
Assumes excavation of materials usingspecialized mechanical excavator.
Assumes transportation of wet sedimentsto staging area in lined 16 cubic yard dumptruck (2 mile round trip).
Assumes excavation of materials usingclamshell.Assumes transportation of wet sedimentsto staging area in lined 16 cubic yard dumptruck (2 mile round trip).
C^__:-U:M<OPPERSV1 54ALT5A.WB2 Page 1 of 5 AR3U2 l *9 30-Sep-99
Table 4-1OA
Alternative 5A - Hershey Run Sediment Removal, Upland Surface Soil and Sediment Removal, Off-Site Thermal Treatment (Thermal Desorption),Groundwater Recovery and Treatment, Monitoring, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
Tcapital (Direct and indirect) .: . -.. . . . . .-- ,,...&
Item
7. Sediment Dewatering/Stabilizationa. Sediment Dewatering Area
a. Sediment Stabilization/Staging Area
c. Sediment Transfer
b. Stabilization of Sediments
8. Sediment Removal (Fire Pond)a. Dewater Pond Area
b. Excavation and transportation to staging areac. Backfill, Grading & Compaction
d. Topsoil
e. Vegetative Cover
9. Sediment Removal (South Pond)a. Dewater Pond Area
b. Excavation and transportation to staging areac. Backfill, Grading & Compaction /
d. Topsoil s
e. Vegetative Cover
10. Soil Removal (K Area)a. Excavation and transportation to staging areab. Backfill, Grading & Compaction
c. Topsoil
d. Vegetative Cover
Quantity
1
1
135,000
135,000
1,300.000
3.50013,000
3,200
4
500.000
4,00011,300
1,200
2
1003,300
400
0.5
uruts
lump sum
lump sum
cubic yard
cubic yard
gallon
cubic yardcubic yard
cubic yard
acre
gallon
cubic yardcubic yard
cubic yard
acre
cubic yardcubic yard
cubic yard
acre
unncosf(i,z)
$56.000
$56,000
$1.75
$3.60
$0.10
$7.25$10.00
$22.00
$3.500
$0.10
$7.25$10.00
$22.00
$3,500
$7.25$10.00
$22.00
$3,500
Mem Cost
$56,000
$56,000
$236,250
$486,000
$130,000
$25,375$130,000
$70,400
$14.000
$50,000
$29,000$113,000
$26,400
$5,250
$725$33,000
$8,800
$1,750
Comment! •— -:w
Cost includes installation of 200 ft x 200 ftnatural dewatering area. Dewatering areaincludes a 3 ft high gravel berm, 20-milVLDPE liner, and 6 in sand drainage layer.
Cost includes installation of 200 ft x 200 ftstabilization/staging area.Stabilization/staging area indudes a 3 fthigh gravel berm. 20-mil VLDPE liner, and6 in sand drainage layer.
Assumes transfer of sediments fromsediment dewatering area to sedimentstabilization/staging area using front endloader.
Assumes the addition of stabilization agentat a quantity of 10% by volume. Assumesmechanical mixing of stabilization agentwith sediments using front end loader.Total sediment volume after addition ofstabilization agent (10% by volume) =148,500 cubic yards (stabilized HersheyRun sediments = 1 10.000 cubic yards,stabilized West Central Drainagesediments = 38,500 cubic yards).
Assumes removal of surface water withestimated depth of 1-feet from 4 acre pondarea. Assumes on-site treatment throughcarbon (disposable GAC units) with on-sitedischarge.
Assumes replacement of excavated soils,plus additional 4 ft of fill required within theFire Pond and 1 ft of fill placed over the 4acre area for hydraulic improvements.
Assumes placement of 6" of topsoil overthe 4 acre area.
Cost indudes seeding and straw mulch tore-establish vegetative cover.
Assumes removal of surface water withestimated depth of 1-feet from 1.5 acrepond area. Assumes on-site treatmentthrough carbon (disposable GAC units)with on-site discharge.
Assumes replacement of excavated soils,plus additional 3 ft of fill required within the1 .5 acre South Pond Area for hydraulicimprovements.
Assumes placement of 6" of topsoil overthe 1 .5 acre area.
Cost indudes seeding and straw mulch tore-establish vegetative cover.
Assumes replacement of excavated soils,plus additional 4 ft of fill required within the0.5 acre K Area for hydraulicimprovements.Assumes placement of 6" of topsoil overthe 0.5 acre area.
Cost indudes seeding and straw mulch tore-establish vegetative cover.
3 -U:\KOPPERS\154ALT5A.WB2 Page 2 of 5A R 3 I U 2 5 0
30-Sep-99
Table 4-1OA
Alternative 5A - Hershey Run Sediment Removal, Upland Surface Soil and Sediment Removal, Off-Site Thermal Treatment (Thermal Desorption),Groundwater Recovery and Treatment, Monitoring, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost EstimateT
Capital (Direct and Indirect)v-s item • • • .
11. Surface soil Removal (Upland Area)a. Excavation and transportation to staging areab. Backfill surface soil excavation area
12. Surface soil Removal (Loading Dock Area)a. Excavation and transportation to staging areab. Backfill surface soil excavation area
13. Loading for Off-Site Disposal
14. Off-Site Thermal Treatment(Thermal Desorption)
a. Thermal Desorption of Hershey Run Sediments
b. Thermal Desorption of West Central Drainage AT
c. Thermal Desorption of Fire Pond Soils
d. Thermal Desorption of South Pond Soils
e. Thermal Desorption of K Area Soils
f. Thermal Desorption of Upland Area Soils
g. Thermal Desorption of Loading Dock Area Soils
15. Groundwater Recovery and Treatment System1
16. NAPL Recovery (3) N
SUBTOTAL15% ENGINEERING & SUPPORT(9)20%CONTINGENCY(10)
Quantity
30,00030,000
10,00010,000
196,100
165,000
57,750
5.250
6.000
150
45,000
15,000
1
1
unto
cubic yardcubic yard
cubic yardcubic yard
cubic yard
ton
ton
ton
ton
ton
ton
ton
lump sum
lump sum
unncost(i>z)
$7.25$10.00
$7.25$10.00
$2.10
$45
$45
$45
$45
$45
$45
$45
$4,500,000
$65,000
Item Cost
$217,500$300,000
$72,500$100,000
$411,810
$7,425,000
$2,598,750
$236,250
$270,000
$6,750
$2,025,000
$675,000
$4,500,000
$65,000
$28.195.061$2.243,747$2,991,662
. : H- .. - .«.
comment* ' -1- • =•?< •.••-'--.-*
Assumes backfill quantities are equal tosoil excavation volumes.
Assumes backfill quantities are equal tosoil excavation volumes.
Assumes loading of soil and stabilizedsediments from staging areas into trucksfor transportation to off-site disposalfacility.Cost indudes transportation of soils andstabilized sediments to Clean Harborsthermal desorption facility in Baltimore,Maryland.
Increase in volume (100,000 cubic yards to1 10,000 cubic yards) due to stabilization.Assumes material is 1 .5 tons per cubicyard (1 10,000 cubic yards x 1 .5 tons/cubicyard = 165.000 ton).
Increase in volume (35,000 cubic yards to38.500 cubic yards) due to stabilization.Assumes material is 1.5 tons per cubicyard (38,500 cubic yards x 1 .5 tons/cubicyard = 57,750 ton).
Assumes material is 1.5 Ions per cubicyard (3,500 cubic yards x 1.5 tons/cubicyard = 5,250 ton).
Assumes material is 1.5 tons per cubicyard (4,000 cubic yards x 1 .5 tons/cubicyard = 6,000 ton).
Assumes material is 1.5 tons per cubicyard (100 cubic yards x 1 .5 tons/cubic yard= 150 ton).
Assumes material is 1 .5 tons per cubicyard (30,000 cubic yards x 1 .5 tons/cubicyard = 45.000 ton).
Assumes material is 1 .5 tons per cubicyard (10,000 cubic yards x 1.5 tons/cubicyard= 15,000 ton).
Assumes treatment of 1 ,200-1 ,500 gpm.Indudes recovery wells, forcemain piping,VOC treatment, metals treatment,treatment building, discharge piping, andsystem start-up.Assumes installation of pilot scale NAPLrecovery within wells MW-2A and MW-8A.
(Not including Item 14-Off-Site Disposal)(Not including Item 14-Off-Site Disposal)
TOTAL: $33.430.469ROUNDED TOTAL: $33.430,000
C_:-U:\KOPPERS\154ALT5A.WB2 Page 3 of 5A R 3 I U 2 5 I
30-Sep-99
Table 4-1OA
Alternative 5A - Hershey Run Sediment Removal. Upland Surface Soil and Sediment Removal, Off-Site Thermal Treatment (Thermal Desorption),Groundwater Recovery and Treatment, Monitoring, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Prefantnarv Cost Estimate I"\nnuai (Operation & Maintenance) cost
Item
1 . Site Access Maintenance
2. Groundwater RecoveryrTreatment System
3. NAPL System Maintenance(4)a. NAPL Recovery
b. NAPL Disposal
4. Groundwater Monitoring(5)a. Groundwater Sampling(6)
b. Analytical(7)
c. Direct Expenses(S)d. Data Evaluation/Reporting
SUBTOTAL15% ENGINEERING & SUPPORT(9)20% CONTINGENCY(IO)
Quantity
1
12
12
1
10
1
11
-units
lump sum
month
month
drum
manday
event
lump sumlump sum
unttcost(i,z)
$10,000
$120,000
$1,200
$1,000
$520
$16.500
$3,700$10,000
• . ':-;<;.;•- „ : ' V ' - .•'.."•.-.•
item Cost
$10,000
$1,440,000
$14,400
$1,000
$5,200
$16,500
$3,700$10,000
$1,500,800$225,120$300,160
. Comments • -.-
Assumes weekly site inspections andannual repairs to site fencing and signs.
Assumes one full-time operator, repairsand maintenance, chemical addition,sludge disposal, utilities, and effluentmonitoring.
Assumes one technidan two days permonth to perform NAPL recovery.
Assumes one 55 gallon drum of NAPL peryear. Cost for transportation andincineration of drummed liquid waste.
Assumes cost for two field technicians for5 days to collect groundwater samples andmonitor for NAPL from 30 monitoring wellsper event.
Thirty samples plus QA/QC per event forPAHs and natural attenuation parameters.
TOTAL $2,026,080ROUNDED TOTAL: $2,026,000
Thirty-Year Present Worth Cost(11) $64.53 Million
G^_U:\KOPPERS\154ALT5A. WB2 Page 4 of 5
A R 3 U 2 5 230-Sep-99
Table 4-1OA
Alternative 5A - Hershey Run Sediment Removal, Upland Surface Soil and Sediment Removal. Off-Site Thermal Treatment (Thermal Desorption),Groundwater Recovery and Treatment, Monitoring, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
General Notes and AssumptionsUnit cost shown includes material and labor, unless otherwise noted.
. Unit cost from Means 1999, unless otherwise noted."3. Cost provided by contractor for similar Blasland, Bouck & Lee, Inc. project.4. NAPL recovery assumed to be complete after five years of system operation. System operation will be evaluated at the end of five year service life.
. Groundwater monitoring will indude the sampling of groundwater and monitoring of NAPL from within 30 existing monitoring wells. Groundwater___ monitoring will be performed quarterly for the first year, semi-annual for the second year, and once per year thereafter.6. Unit cost assumes labor rate of $65/hour for an eight hour day (Blasland, Bouck & Lee, Inc. senior field technician rate).7. Laboratory analytical cost indudes analysis for PAHs. Additional analytical parameters to facilitate the monitoring of natural attenuation indude; dissolved
oxygen, oxidation-reduction potential, ferric/ferrous iron, nitrate/nitrite, and surfate/surfite._ Direct expenses consist of sampling equipment and subsistence (meals, lodging, vehicle).9. A15 percent contingency for Engineering & Support cost indudes, but is not limited to the following: administration and supervision, design and
development, monitoring and testing, and cost estimating. Engineering & Support cost does not indude legal fees and permit acquisition. Engineering &Support cost developed based upon EPA 600/8-87/049 "Remedial Action Costing Procedures Manual" (1987).A 20 percent contingency allowance is induded to provide for unforseen circumstances or variability in estimated areas, volumes, and labor and material
~~ costs. Contingency allowance developed based upon EPA 600/8-87/049 "Remedial Action Costing Procedures Manual" (1987).11. Present worth cost is based on a total capital (direct and indirect) expenditure (taken in the first year) and annual (operation and maintenance) costs taken
over a 30-year time frame at a discount rate of five percent per EPA Guidance (EPA/540/G-89/004).
A R 3 I U 2 5 3G(_U:«OPPERSM 54ALT5A.WB2 Page 5 of 5 30-S«p-99
Table 4-1 OB
Alternative SB - Hershey Run Sediment Removal, Upland Surface Soil and Sediment Removal, Off-Site Thermal Treatment (Incineration),Groundwater Recovery and Treatment, Monitoring, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport Site |j| |DJ lj\ 1CFeasibility Study oil Iftt tfV IT
Preliminary Cost Estimate
TCapital (Direct and Indirect) • , : * • : • ^ --„.•,.
' '"W-- Item -•-•: .- .• :• : ;• : - ' • - - • ' • -
1. Mobilization/Demobilization2. Site Preparation
a. Clear & Grub Dense Brush
b. Equipment Decontamination Area
c. Silt Fendng
d. Access Roads
e. Access Roads (Hershey Run)
f. Drainage Culverts
3. Archaeological Evaluation
4. Temporary Sheeting (flow diversion)a. Hershey Run Sheeting
5. Sediment Excavation (Hershey Run)a. Sediment Excavation
b. Transportation to Staging/Dewatering Area/
6. Sediment Excavation (West Central Drainage Areaa. Sediment Excavation
N
b. Transportation to Staging/Dewatering Area
Quantity
1
26.0
1.0
44,000
7,600
4,600
15
1.0
125,000
100,000
100,000
35,000
35,000
Units |UnttCosU1,2)| Item Cost
lump sum
acre
lump sum
linear feet
linear feet
linear feet
each
lump sum
square feet
cubic yard
cubic yard
cubic yard
cubic yard
5%
$600
$23,000
$1.00
$23.00
$41.00
$1,000
$700.000
$11.25
$21.00
$9.00
$35.00
$9.00
$712,301
$15,600
$23,000
$44,000
$174,800
$188,600
$15,000
$700,000
$1,406,250
$2,100,000
$900,000
$1,225,000
$315,000
Comments . •- ; :••* -s
Five percent of items 2 through 13, 15, and16.
Assumes dear & grub of Fire Pond, SouthPond, K Area, and Upland Areas.
Assumes 20' x 40' concrete slab, sump,collection tank, pressure washer, andpiping.
Assumes silt fence placed along perimeterof excavation areas and along each side ofaccess roadways.
Assumes 12 feet wide, geotextile fabric,12-inch crushed stone layer, grading aridcompaction for access roads to Fire Pond,South Pond, K Area, and Upland Areasand access to Hershey Run.
Assumes 12 feet wide, two layers ofgeotextile fabric, 24-inch gravel layer, and1 2-inch crushed stone layer, grading andcompaction for access roads to towlyingareas along existing Hershey Run tofacilitate excavation of sediments.
Assumes placement of 12" diameter CMP,tapered end pieces, bank run fill, andrip-rap at approximately 10 locations alongaccess roadways.
Assumes performance of Phase IIarchaeological evaluations and Phase IIIdata recovery excavations for areasimpacted by construction activities.
Assumes installation and recovery of 16'vertical lengths of steel sheeting. Sheetingwill be required along the length of thecenter of Hershey Run (5,200 linear feet)for flow diversion during sedimentexcavation. Additional sheeting will beinstalled at 100' increments to separateexcavation areas from flow of water.
Assumes excavation of materials usingspecialized mechanical excavator.
Assumes transportation of wet sedimentsto staging area in lined 16 cubic yard dumptruck (2 mile round trip).
Assumes excavation of materials usingclamshell.
Assumes transportation of wet sedimentsto staging area in lined 16 cubic yard dumptruck (2 mile round trip).
&>-C;-U:\KOPPERSM 54ALT5B.WB2 Page 1 of SAR3U251*
30-Sep-99
Table 4-1 OB
Alternative SB - Hershey Run Sediment Removal. Upland Surface Soil and Sediment Removal, Off-Site Thermal TreatmenUlncineration),Groundwater Recovery and Treatment, Monitoring, Institutional Controls, and Pilot Study Rl |8)
Former Koppers Company. Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
v; item :
7. Sediment Dewatering/Stabilizationa. Sediment Dewatering Area
a. Sediment Stabilization/Staging Area
c. Sediment Transfer
b. Stabilization of Sediments
8. Sediment Removal (Fire Pond)a. Dewater Pond Area
b. Excavation and transportation to staging areac. Backfill, Grading & Compaction
d. Topsoil
e. Vegetative Cover
9. Sediment Removal (South Pond)a. Dewater Pond Area
b. Excavation and transportation to staging areac. Backfill, Grading & Compaction
d. Topsoil%
e. Vegetative Cover
10. Soil Removal (K Area) ,a. Excavation and transportation to staging areab. Backfill, Grading & Compaction
c. Topsoil
d. Vegetative Cover
Quantity
1
1
135,000
135,000
1,300,000
3,50013,000
3,200
4
500,000
4,00011,300
1,200
2
1003,300
400
0.5
Unto
lump sum
lump sum
cubic yard
cubic yard
gallon
cubic yardcubic yard
cubic yard
acre
gallon
cubic yardcubic yard
cubic yard
acre
cubic yardcubic yard
cubic yard
acre
-,- •unKcom(1tZ)
$56,000
$56,000
$1.75
$3.60
$0.10
$7.25$10.00
$22.00
$3,500
$0.10
$7.25$10.00
$22.00
$3,500
$7.25$10.00
$22.00
$3,500
Hem Cost
$56,000
$56.000
$236,250
$486,000
$130,000
$25,375$130,000
$70,400
$14,000
$50,000
$29,000$113,000
$26,400
$5,250
$725$33,000
$8,800
$1,750
comments a-
Cost indudes installation of 200 ft x 200 ftnatural dewatering area. Dewatering areaindudes a 3 ft high gravel berm. 20-mlVLDPE liner, and 6 in sand drainage layer.
Cost indudes installation of 200 ft x 200 ftstabilization/staging area.Stabilization/staging area indudes a 3 fthigh gravel berm, 20-mil VLDPE liner, and6 in sand drainage layer.Assumes transfer of sediments fromsediment dewatering area to sedimentstabilization/staging area using front endloader.Assumes the addition of stabilization agentat a quantity of 10% by volume. Assumesmechanical mixing of stabilization agentwith sediments using front end loader.Total sediment volume after addition ofstabilization agent (10% by volume) =148,500 cubic yards (stabilized HersheyRun sediments = 1 10,000 cubic yards,stabilized West Central Drainagesediments = 38,500 cubic yards).
Assumes removal of surface water withestimated depth of 1-feet from 4 acre pondarea. Assumes on-site treatment throughcarbon (disposable GAC units) with on-sitedischarge.
Assumes replacement of excavated soils,plus additional 4 ft of fill required within theFire Pond and 1 ft of fill placed over the 4acre area for hydraulic improvements.
Assumes placement of 6" of topsoil overthe 4 acre area.
Cost indudes seeding and straw mulch tore-establish vegetative cover.
Assumes removal of surface water withestimated depth of 1-feet from 1.5 acrepond area. Assumes on-site treatmentthrough carbon (disposable GAC units)with on-site discharge.
Assumes replacement of excavated soils,plus additional 3 ft of fill required within the1 .5 acre South Pond Area for hydraulicimprovements.
Assumes placement of 6" of topsoil overthe 1.5 acre area.
Cost indudes seeding and straw mulch tore-establish vegetative cover.
Assumes replacement of excavated soils,plus additional 4 ft of fill required within the0.5 acre K Area for hydraulicimprovements.Assumes placement of 6" of topsoil overthe 0.5 acre area.
Cost indudes seeding and straw mulch tore-establish vegetative cover.
<*_^-U:\KOPPERSM 54ALT5B.WB2 Page 2 of 5 A R 3 U 2 5 5 30-Sep-99
Table 4-10B
Alternative SB - Hershey Run Sediment Removal, Upland Surface Soil and Sediment Removal, Off-Site Thermal Treatment (Incineration).Groundwater Recovery and Treatment Monitoring, Institutional Controls, and Pilot Study ( p.
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
TCapital (Direct and indued)
Item
1 1 . Surface soil Removal (Upland Area)a. Excavation and transportation to staging areab. Backfill surface soil excavation area
12. Surface soil Removal (Loading Dock Area)a. Excavation and transportation to staging areab. Backfill surface soil excavation area
13. Loading for Off-Site Disposal
4. Off-Site Thermal TreatmentIncineration)
a. Incineration of Hershey Run Sediments
b. Incineration of West Central Drainage Area Sedi
c. Incineration of Fire Pond Soils
d. Incineration of South Pond Soils
e. Incineration of K Area Soils
f. Incineration of Upland Area Soils
g. Incineration of Loading Dock Area Soils
1 5. Groundwater Recovery and Treatment System/
16. NAPL Recovery (3) s
SUBTOTAL15% ENGINEERING & SUPPORT(9)20%CONTINGENCY(10)
Quantity
30,00030.000
10,00010,000
196,100
165,000
57,750
5,250
6,000
150
45,000
15,000
1
1
unto
cubic yardcubic yard
cubic yardcubic yard
cubic yard
ton
ton
ton
ton
ton
ton
ton
lump sum
lump sum
unitcostdjz)
$7.25$10.00
$7.25$10.00
$2.10
$715
$715
$715
$715
$715
$715
$715
$4,500,000
$65,000
.f • • •
. Item Cost
$217.500$300.000
$72,500$100.000
$411,810
$117,975,000
$41,291,250
$3,753,750
$4,290,000
$107,250
$32.175,000
$10,725,000
$4,500,000
$65,000
$225,275,560$2,243,747$2,991 ,662
comments ••,:•' ^\-
Assumes backfill quantities are equal tosoil excavation volumes.
Assumes backfill quantities are equal tosoil excavation volumes.
Assumes loading of soil and stabilizedsediments from staging areas into trucksfor transportation to off-site disposalfacHttv.Cost indudes transportation of soils andstabilized sediments to incineration facilitylocated in Calvert City, Kentucky.
Increase in volume (100,000 cubic yards to1 10,000 cubic yards) due to stabilization.Assumes material is 1 .5 tons per cubicyard (1 1 0,000 cubic yards x 1 .5 tons/cubicyard = 165,000 ton).
Increase in volume (35.000 cubic yards to38.500 cubic yards) due to stabilization.Assumes material is 1 .5 tons per cubicyard (38,500 cubic yards x 1 .5 tons/cubicyard = 57,750 ton).
Assumes material is 1 .5 tons per cubicyard (3,500 cubic yards x 1 .5 tons/cubicyard = 5,250 ton).
Assumes material is 1 .5 tons per cubicyard (4,000 cubic yards x 1 .5 tons/cubicyard = 6,000 ton).
Assumes material is 1 .5 tons per cubicyard (100 cubic yards x 1 .5 tons/cubic yard= 150 ton).
Assumes material is 1 .5 tons per cubicyard (30,000 cubic yards x 1 .5 tons/cubicyard = 45,000 ton).
Assumes material is 1 .5 tons per cubicyard (10,000 cubic yards x 1 .5 tons/cubicyard = 15,000 ton).
Assumes treatment of 1 ,200-1 ,500 gpm.Indudes recovery wells, forcemain piping,VOC treatment, metals treatment,treatment building, discharge piping, andsystem start-up.Assumes installation of pilot scale NAPLrecovery within wells MW-2A and MW-8A.
(Not induding Item 14-Off-Site Disposal)(Not induding Item 14-Off-Site Disposal)
TOTAL: $230,510,969ROUNDED TOTAL: $230,51 1 ,000
A R 3 U 2 5 6<^C-U:\KOPPERSM 54ALT5B.WB2 Page 3 of 5 30^0-99
Table 4-106
Alternative SB - Hershey Run Sediment Removal, Upland Surface Sol and Sediment Removal, Off-Site Thermal Treatment (Incineration),Groundwater Recovery and Treatment, Monitoring, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
TAnnual (Operation & Maintenance) cost
Item
1 . Site Access Maintenance
2. Groundwater Recovery/Treatment System
3. NAPL System Maintenance(4)a. NAPL Recovery
b. NAPL Disposal
4. Groundwater Monitoring(5)a. Groundwater Sampling(6)
b. AnalyticalfT)
c. Direct Expenses(8)d. Data Evaluation/Reporting
SUBTOTAL15% ENGINEERING & SUPPORT(9)20%CONTINGENCY(10)
Quantity
1
12
12
1
10
1
11
Unto
lump sum
month
month
drum
manday
event
lump sumlump sum
unKCoeuiiZ)
$10,000
$120.000
$1,200
$1,000
$520
$16,500
$3,700$10.000
Item Cost
$10,000
$1,440,000
$14,400
$1,000
$5,200
$16.500
$3,700$10.000
$1.500.800$225.120$300.160
. '. - - . : :,-•;.
. ." '• r- r.. .•-.... comments 3*-- .••*. •
Assumes weekly site inspections andannual repairs to site fencing and signs.
Assumes one full-time operator, repairsand maintenance, chemical addition,sludge disposal, utilities, and effluentmonitoring.
Assumes one technician two days permonth to perform NAPL recovery.
Assumes one 55 gallon drum of NAPL peryear. Cost for transportation andincineration of drummed liquid waste.
Assumes cost for two field technicians for5 days to coflect groundwater samples andmonitor for NAPL from 30 monitoring wellsper event.
Thirty samples plus QA/QC per event forPAHs and natural attenuation parameters.
TOTAL $2,026,080ROUNDED TOTAL: $2,026,000
Thirty-Year Present Worth Cost(11) $262 Million
G U:\KOPPERSM 54ALT5B. WB2A R 3 I U 2 5 7
Page 4 of 5 30-Sep-99
Table 4-1 OB
Alternative SB - Hershey Run Sediment Removal, Upland Surface Soi and Sediment Removal, Off-Site Thermal Treatment (Incineration).Groundwater Recovery and Treatment, Monitoring, Institutional Controls, and Pilot Study
Former Koppers Company, Inc. - Newport SiteFeasibility Study
Preliminary Cost Estimate
General Notes and AssumptionsUnit cost shown includes material and labor, unless otherwise noted.
— Unit cost from Means 1999, unless otherwise noted.3. Cost provided by contractor for similar Blasland, Bouck & Lee, Inc. project.' NAPL recovery assumed to be complete after five years of system operation. System operation will be evaluated at the end of five year service life.
Groundwater monitoring will indude the sampling of groundwater and monitoring of NAPL from within 30 existing monitoring wells. Groundwater_ monitoring will be performed quarterly for the first year, semi-annual for the second year, and once per year thereafter.
Unit cost assumes labor rate of $65/hour for an eight hour day (Blasland. Bouck & Lee, Inc. senior field technician rate)Laboratory analytical cost indudes analysis for PAHs. Additional analytical parameters to facilitate the monitoring of natural attenuation indude; dissolvedoxygen, oxidation-reduction potential, ferric/ferrous iron, nitrate/nitrite, and surfate/sutfite.
_ Direct expenses consist of sampling equipment and subsistence (meals, lodging, vehicle).9. A 15 percent contingency for Engineering & Support cost indudes. but is not limited to the following: administration and supervision, design and
development, monitoring and testing, and cost estimating. Engineering & Support cost does not indude legal fees and permit acquisition. Engineering &Support cost developed based upon EPA 600/8-67/049 "Remedial Action Costing Procedures Manual" (1987).
1_ A 20 percent contingency allowance is induded to provide for unforseen circumstances or variability in estimated areas, volumes, and labor and materialcosts. Contingency allowance developed based upon EPA 600/8-87/049 "Remedial Action Costing Procedures Manual" (1987).
11. Present worth cost is based on a total capital (direct and indirect) expenditure (taken in the first year) and annual (operation and maintenance) costs takenover a 30-year time frame at a discount rate of five percent per EPA Guidance (EPA/540/G-89/004).
6.7
A R 3 U 2 5 83(—U:\KOPPERSV154ALT5B.WB2 Page 5 of 5 30-Sep-99
FiguresB L A S L A N D , BOUCK & L E E . INC.
e n g i n e e r s & s c i e n t i s t s
A R 3 U 2 5 9
• • • • • : - /FARMER KOPPERS /GOMPANYJNC. S(TE /
" '
MAP SOURCE:UNITED STATES GEOLOGICAL SURVEY7.5 MINUTE TOPOGRAPHIC QUADRANGLESERIES 'NEWARK EAST. DE" (1993) AND•WILMINGTON SOUTH, DE-NJ" (1993)
PENN.
SITE
2000 2000
APPROXIMATE SCALE IN FEET
05/99 SYR-D54-DJH38717001O8717n01.cdr
A R 3 U 2 0 Q
FORMER KOPPERS COMPANY, INC. NEWPORT SITENEWPORT. DELAWARE
FEASIBILITY STUDY
SITE LOCATION MAP
BBL BLAStANg BOUCK » LEE. INC.. •ngfnaart at identlstt
FIGURE
1-1
DRAFT
« A PROCESS AREA* J DRIP TRACK AREA
2) WOOD STORAGE AREA••X
3} FIRE POND AREA««X
4) SOUTH PONDS AREAh_X
5) K AREA*_X
6) REMAINING UPLANDS•_x
7) HERSHEY RUN DRAINAGE AREA•
8) CENTRAL DRAINAGE AREAs—X
— SITE BOUNDARY
WE1UNDS BOUNDARY
NOTES:
1. ALL "AREA" BOUNDARIES AREAPPROXIMATE.
2. MAPPING BASED ON DATA PROVIDED BYWOODWARD-CLYDE. APRIL. 1997.
500'
GRAPHIC SCALE
1000'
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FORMER KOPPERS COMPANY. INC. NEWPORT SITENEWPORT. DELAWARE
FEASIBILITY STUDY
SITE PLAN
HHJL BUSUMD. MUCK t LEE. IMC.engineers A scientists
FIGURE
DRAFT
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STE BOUNDARY
WETLANDS BOUNDARY
APPROXIMATE AREA OF VISUALDELINEATION OF WEATHEREDCREOSOTE NAPL DEPOSTS
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FORMER KOPPERS COMPANY. INC. NEWPORT SITENEWPORT, DELAWARE
FEASIBILITY STUDY
SURFICIAL CREOSOTE NAPLDEPOSITS DELINEATION
BUSUHD. BOUCK > LEE. INC.& scientists
FIGURE
1-3
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LEGEND:
SAMPLE LOCATION WITH NAPL OBSERVEDIN SUBSURFACE SOILS
SAMPLE LOCATION WITH NAPL INFERRED TO BEPRESENT IN SUBSURFACE SOILS
SAMPLE LOCATION WITH NO NAPLPRESENT IN SUBSURFACE SOILS
9TE BOUNDARY
WETLANDS BOUNDARY
EXTENT OF PROBABLE NAPL ZONE(DASHED WHERE INFERRED)
NOTE:1. MAPPING AND SAMPLE LOCATIONS BASED
ON DATA PROVIDED BY WOODWARD-CLYDE.APRIL. 1997.
^ \\ '
//*
400'
GRAPHIC SCALE
800'
•/ iU ON-«, OfT-RCTP: 8LSPEC9/29/N SYR-M-KLN NCS VCCM717100/38717101.0*0 A R 3 U 2 6 3
FORMER KOPPERS COMPANY. INC. NEWPORT SITENEWPORT. DELAWARE
FEASIBILITY STUDY
EXTENT OF NAPL BELOWTHE WATER TABLE
BBL BUSUHO. BOUCK t LEE. INC.engineers & scientists
FIGURE
1-4
' | V x ' / ^WCM-CiWl WCM-CX1\
"I ~ \ '"'' ,x • VKCM-C4
DRAFT
NOTE:
', 1. MAPPING AND SAMPLE LOCATIONS BASED\ ON DATA PROVIDED BY WOODWARO-aYOE.
APRIL. 1997.
LEGEND
WCU-C21 NAPL OBSERVED
— — SITE BOUNDARY
WETLANDS BOUNDARY
400'
GRAPHIC SCALE
800*
FORMER KOPPERS COMPANY, INC. NEWPORT SITENEWPORT. DELAWARE
FEASIBILITY STUDY
NAPL DELINEATION IN SEDIMENT
X: J8717XOJ.OWCU ON.«. OFF.REFP: 8LSPEC9/29/M SYR-M-KIN YCCJ8717100/38717C04.DWG
BBL BUSUHO. BOUCK t LEE, MC.•ng/neers A scientists
FIGURE
1-5
Establish Risk Management Coals
Minimize potential unacceptablehuman hearth riskMinimize potential unacceptableecological riskOptimize beneficial uses of siteBalance benefits and costs
DRAFT
ConductHuman Health and Ecological
Risk Assessments
Potentialrisk to
ecologicalreceptors
?
Potentialrisk to
human hearth
Synthesize Results of 12 Assessment Endpoints
Toxlcfty
1. Wetland community(amphipod and midge)
2. Benthic community(amphipod and midge)
3. Upland soil (earthworm)
5. Fish (fish embryo)6. Amphibian (frog embryo)
Localized sedimenttoxicityLocalized soil toxicity
Food Web
5. Fish7. Piscivorous birds8. Worm-eating birds9. Carnivorous birds10. Carnivorous mammals11. Omnivorous mammals12. Terrestrial herbivores
No unacceptable riskbased on LOAEL values
Field Surveys
1. Wetland plant community3. Upland soil community4. Terrestrial plant
community
2. Benthic communities5. Fish6. Amphibians
Abundant and diversewetland plantsGenerally abundant anddiverse benthic communityAbundant and reproducingpopulations of amphibiansand fishesAbundant and diverseterrestrial plantsLocalized physical effectsfrom weathered NAPL
Figure 1-6. Evaluation of assessment endpoints for the former KoppersCompany, Inc., Newport, Delaware site.
A R 3MOOB»COO»090« 080089 WA
ion n ce
Establish Risk Management Goals
Minimize potential unacceptablehuman health riskMinimize potential unacceptableecological riskOptimize beneficial uses of siteBalance benefits and costs
DRAFT
Potentialrisk to
ecologicalreceptors.. 9
Toxicity
1 . Wetland community(amphipod and midge)
2. Benthic community(amphipod and midge)
3. Upland soil (earthworm)
5. Fish (fish embryo)6. Amphibian (frog embryo)
Localized sedimenttoxicity
Localized soil toxicity
Food Web
5. Fish7. Piscivorous birds8. Worm-eating birds9. Carnivorous birds10. Carnivorous mammals11. Omnivorous mammals12. Terrestrial herbivores
• No unacceptable riskbased on LOAEL values
Field Surveys
1 . Wetland plant community3. Upland soil community4. Terrestrial plant
community
2. Benthic communities5. Fish6. Amphibians
Abundant and diversewetland plants
Generally abundant anddiverse benthic community
Abundant and reproducingpopulations of amphibiansand fishes
Abundant and diverseterrestrial plants
Localized physical effectsfrom weathered NAPL
Sediments
Reduce potentialunacceptable risks 10 thestructure and function ofthe benthicmacroinvertebratecommmunityMinimize disturbance tothe existing wetland plantcommunity
Soil
• Prevent the futureexposure of industrialworkers to soil withpotential unacceptablerisks
• Reduce the spatial extentof weathered (physicallydisturbed) NAPL areaslocated at or near the soilsurface
• Minimize disturbance ofexisting terrestrial plantcommunity
Groundwater
Prevent future exposure ofhuman receptors togroundwater containing
Figure 2-1. Remedial action objectives derived from risk assessment.
A R 3 U 2 6 6 eeooBic.oot 0901 oe/avw WA
Upland Soils
Fire0 Pond
EastCentralMarsh
SouthPonds
100 200 300 Fwt
KArea
LEGEND
DRAFT
'//. Soil creosote areas (BB&L)
'/// Sediment creosote areas
O Soil sampling location that exceededecotoxicology threshold
t Soil sampling location that did notexceed ecotoxicology threshold
•
O
CHCD
Sediment sampling location thatexceeded ecotoxicology threshold
Sediment sampling location that didnot exceed ecotoxicology threshold
Nontidal emergent wetland
Nontidal forested wetland
Nontidal scrub/shrub wetland
Open water
Tidal marsh
Upland forested
Upland herbaceousUpland scrub/shrub
Figure 2-2. Surficial creosote areas and soiland sediment sampling locationswith TPAH concentration greaterthan ecotoxicological threshold
960081 C.001 OKI I Aug2S.199SI CarffrHon 7OV9i I Catfeiixn 7/2&9S I g:Vmf>f»n\prai«Xs*oc.lpr
A R 3 U 2 6 7
BLASLAND, BOUCK & LEE, INC.
engineers A s c i e n t i s t s
Appendix A
A R 3 U 2 6 8
DRAFT
Appendix A - Preliminary Natural Attenuation Assessment
Predicted or Theoretical Transport Versus Actual Constituent Distribution and Concentrations
PAH and BTEX compounds detected in groundwater at the interior upland monitoring wells MW-2A and MW-8A
have not migrated beyond the Site boundaries. In fact, the groundwater constituents at the Site exhibit a significant
decrease in concentration along the flowpaths downgradient from MW-2A and MW-8A. Considering the length of
time since creosote was used at the Site (approximately 20-70 years), this lack of PAHs and BTEX migration suggests
that natural attenuation mechanisms have limited the movement of these constituents in groundwater at the Site.
The effects of natural attenuation on the spatial distribution of BTEX in groundwater were evaluated by comparing
actual constituent groundwater concentrations and distribution (based on groundwater sampling and analysis) to the
predicted extent based on constituent transport predicted on the basis of advection and retardation.
This method required an estimate of each constituent's potential migration rate in groundwater, which is a function
of the groundwater velocity and the constituent's retardation factor (see attachment). The average linear groundwater
flow velocity in the upper hydrostratigraphic unit was approximately 1.8 feet/day (approximately 660 ft/yr).
Once each constituent's retardation factor was calculated, the constituent's potential migration rate in groundwater
was estimated by dividing the average linear groundwater velocity by the retardation factor (RJ. The predicted extent
of migration was then calculated by multiplying the constituent's velocity and the estimated time since wood-treating
operations ceased at the Site (assumed to be 20 years). This is a conservative assumption since the Site was in active
use from 1929 to 1971. If the measured concentration is less than predicted considering constituent velocity only,
it is good indication that natural attenuation processes are occurring.
Benzene
Benzene's retardation factor for the Site is 1.45, resulting in a potential migration rate of 453 feet/year in
groundwater. Within the 20-year migration time frame, benzene should have migrated approximately 9,100 feet
downgradient from MW-2A. However, benzene was not detected at MW-4A, MW-9A, and MW-15A which are
located approximately 1,400 feet, 800 feet and 550 feet, respectively, downgradient from MW-2A. Benzene was
detected at low concentrations (2 Mg/L estimated value) at MW-10A which is located approximately 800 feet
BLASLAND. BOUCK & LEE, INC.10/1/99 engineers * scientists A-1
A R 3 U 2 6 9
DRAFT
downgradient of MW-2A. This difference in the observed benzene distribution and theoretical benzene distribution
suggests benzene is being naturally attenuated in groundwater at the Site.
Toluene
Toluene's retardation factor for the Site is 3.28, resulting in a potential migration rate of 201 feet/year. Within the
20-year migration time frame, toluene should have migrated approximately 4,000 feet from MW-2A and MW-8A.
However, toluene was not detected at MW-9A, MW-15A, MW-12A, and MW-5A (located 800 feet downgradient
of MW-2A, 550 feet downgradient of MW-2A and 300 feet downgradient of MW-8A, 1,750 feet downgradient of
MW-8A, and 900 feet downgradient of MW-8A, respectively). Toluene was detected at low concentrations at MW-
10A (up to 4 wg/L estimated value) and at MW-4A (up to 0.7 wg/L) which are located approximately 800 feet and
1,400 feet downgradient of MW-2A, respectively. This difference in the observed and theoretical distribution
suggests toluene is being naturally attenuated in groundwater at the Site.
Ethylbenzene
Ethylbenzene's retardation factor for the Site is 2.21, resulting in a potential migration rate of 297 feet/year. Within
the 20-year migration time frame, ethylbenzene should have migrated approximately 5,900 feet from MW-2A and
MW-8 A. However, ethylbenzene was not detected at MW-4 A, MW-15 A, MW-12 A and MW-5 A (which are located
1,400 feet downgradient of MW-2A, 550 feet downgradient of MW-2A and 300 feet downgradient of MW-8A, and
900 feet downgradient of MW-8 A, respectively). Ethylbenzene was detected at low concentrations at MW-10A [up
to 9 wg/L (estimated value)] and at MW-9A [up to 4 wg/L (estimated value)] which are located 800 feet and 1,400
feet downgradient of MW-2A, respectively. This difference in the observed and theoretical ethylbenze distribution
suggests ethylbenzene is being naturally attenuated in groundwater at the Site.
Xylene
The retardation factor for xylene is 5.31 at the Site, resulting in a potential migration rate of 124 feet/year. Within
the 20-year migration time frame, xylene should have migrated approximately 2,500 feet from MW-2A and MW-8A.
However, xylene was not detected at MW-4A, MW-9A, MW-15A, MW-12A and MW-5 A (which are located 1,400
feet downgradient of MW-2A, 800 feet downgradient of MW-2A, 550 feet downgradient of MW-2A and 300 feet
downgradient of MW-8A, 1,750 feet downgradient of MW-8A, and 900 feet downgradient of MW-8 A, respectively).
Xylene was detected at low concentrations at MW-10A (up to 10 wg/L) which is located 800 feet downgradient of
BLASLAND. BOUCK & LEE, INC.engineers & scientists A-2
A R 3 U 2 7 U
DRAFT
MW-2A. This difference in the observed and theoretical xylene distribution suggests xylene is being naturally
attenuated within groundwater at the Site.
PAHs
PAHs could not be evaluated using this method (as was done with the BTEX constituents), because of the high PAH
retardation factors.
Geochemical Evidence of Natural Attenuation
An evaluation of geochemical indicators was used as a supportive method to evaluate natural attenuation of PAHs
and BTEX in groundwater at the Site. This method of analysis is based upon the availability and usage of electron
acceptors. An electron acceptor is a compound that is capable of receiving one or more electrons. If groundwater
has elevated levels of reduced compounds (e.g., greater than 1 ppm of ammonia, ferrous iron, sulfide, or methane)
relative to the surrounding groundwater, it is indicative of intrinsic biodegradation.
Dissolved Oxygen
As shown on Figure 3-1, there is a zone of depleted DO concentrations centered around MW-2A and MW-8A. The
DO concentrations in groundwater at monitoring wells MW-2A and MW-8A were below 1.0 mg/L. This is in sharp
contrast to the upgradient DO concentrations greater than 9 mg/L at monitoring well MW-14A and the downgradient
DO concentration of 10 mg/L at monitoring well MW-15A. This zonation of depleted DO concentrations indicates
that groundwater entering the Site is well oxygenated and that dissolved oxygen is depleted within the Process Area
and Wood Storage Area. The zone of depleted DO concentrations indicates the probable presence of aerobic
metabolic processes that biodegrade PAHs and BTEX.
Sum of Nitrite and Nitrate
The sum of nitrite and nitrate concentrations (Figure 3-2) has a spatial trend similar to DO concentrations. A zone
of low nitrate and nitrite concentrations is present at the site that is coincident with the location of the detected BTEX
and PAH compounds. A large region of nitrite and nitrate less than 0.1 ng/L encompasses the Process Area and
Wood Storage Area, particularly the area near monitoring well clusters MW-2, MW-5, and MW-8. This
concentration compared with the 0.9 ng/L groundwater entering the Site demonstrates that nitrate and nitrite are likely
BLASLAND, BOUCK & LEE, INC.-10/1/99 engineers 4 scientists A-3
A R 3 U 2 7 I
DRAFT
being consumed as electron acceptors and depleted in groundwater at the Site. This depleted nitrite and nitrate zone
is coincident with the BTEX and PAH source areas and is further evidence that suggests biodegradation.
Other Natural Attenuation Processes
Dispersion and biological degradation are other types of natural attenuation processes that can reduce the mass and
mobility of constituents in groundwater and naturally attenuate concentrations of PAHs and BTEX. Dispersion is
a physical process dependent on the hydrogeology of the aquifer. Biodegradation is a function of the presence of
microbes, sufficient electron donors, and Site conditions favorable to microbial population growth. Dispersion and
biological degradation contribute to the reduction of constituent concentrations in groundwater.
Dispersion
Dispersion is a natural attenuation process by which a solute tends to spread out from the path that it would be
expected to follow accordingly to advective hydraulics (Freeze and Cherry, 1979). Dispersion can occur on a
microscopic scale because of mechanical mixing, nonuniform velocity distributions within pore spaces, and tortuous
pathlines that groundwater follows during movement through interconnected soil pores of different sizes and shapes.
On the macroscopic scale, dispersion results from geologic heterogeneities such as layers and lenses of contrasting
soil types (i.e., varying hydraulic conductivity). Soils at the Site were observed to contain horizontal layers or lenses
of materials that are coarser or finer grained than the surrounding aquifer material, resulting in zones of significantly
higher or lower permeability. For constituent transport, the higher permeability zones are more important because
they determine the maximum distance over which dissolved constituents will migrate from the source area. Thus,
dispersion is expected to be a significant natural attenuation process for PAHs and BTEX in groundwater.
Biological Degradation
Biological degradation of PAHs and BTEX in groundwater is primarily due to the presence of bacteria which both
adhere to soil particles within the aquifer and move with groundwater flow. Bacteria involved in the biodegradation
of organic constituents are for the most part heterotrophic, and require organic compounds for growth and
reproduction, with the organic compounds serving as sources for carbon and energy (Atlas, 1984). Heterotrophs are
ubiquitous in the subsurface and obtain energy by transferring electrons from oxidizable organic compounds (electron
donors, or substrates) to reducible compounds (electron acceptors). This energy-producing process is referred as
metabolic respiration. Bacteria use available carbon for these biosynthetic processes.
BLASLAND. BOUOC & LEE. INC.F^USTOJ ^0699AJ>PA.WPD -10/1/99 engineers A scientists A-4
ftR3ii*272
DRAFT
Aerobic heterotrophs use oxygen as the electron acceptor during aerobic respiration. In anaerobic environments,
microorganisms gain energy by using alternative electron acceptors (other than oxygen) for metabolic respiration
processes. Primary alternate electron acceptors are nitrate, Fe(III), Mn(TV), sulfate, and carbon dioxide. Organisms
that use these electron acceptors are referred to as denitrifying, manganese-reducing, iron-reducing, sulfate-reducing,
and methanogenic bacteria, respectively. Denitrifiers reduce nitrate to nitrogen gas. Iron reducers reduce Fe(III) to
Fe(II), while manganese reducers reduce Mn(IV) to Mn(II). Sulfate reducers reduce sulfate to sulfide, and
methanogens produce methane from the reduction of carbon dioxide.
The electron acceptor hierarchy, based on energy liberated, is as follows (Nyer et al., 1996):
Oxygen reduction: molecular oxygen (O2) -» water (H2O)
Nitrate reduction: nitrate (NO3) ->• molecular nitrogen (N2)
Manganese reduction: tetravalent manganese [Mn(FV)] -*• divalent
manganese [Mn(II)J
Iron reduction: ferric iron [Fe(III)] ->• ferrous iron [Fe(II)]
Sulfate reduction: sulfate (SO/2) -»• sulfide (H2S)
Methanogenesis: carbon dioxide (COj) ->• methane (CHJ
Aquifer systems may contain many microenvironments that support different microorganisms (Chapelle, 1993). The
type of metabolic activity occurring can be observed by evaluating changes in the geochemistry over time or along
a flowpath. For example, dissolved oxygen, total nitrate/nitrite, and sulfate/sulfide concentrations in groundwater
samples collected upgradient, near potential sources, and downgradient of a source can be used to deduce whether
natural attenuation of PAHs and BTEX is occurring by means of biodegradation. Dissolved oxygen, nitrate, and
nitrite concentrations were measured in Site groundwater samples and were used to support this preliminary
evaluation of natural attenuation. The data are discussed below.
BLASLAND, BOUCK & LEE, INC.FAUSB«|U\0699APPA.WPO- iD/i/99 engineers A scientists A-5
A R 3 U 2 7 3
DRAFT
Biodegradation of BTEX Compounds
B iodegradation of BTEX compounds has been demonstrated under oxygen-reducing, nitrate- reducing, iron-reducing,
sulfate-reducing, and methanogenic conditions (Boone, et al., 1996; Young and Cerniglia, 1995; Lovely, 1996). The
biodegradation of BTEX compounds by aerobic bacteria is well established and has been demonstrated and utilized
at many Sites throughout the United States (Chapelle, 1993). Aerobic biodegradation rate constants for benzene have
been reported ranging from several days to years (Mackay, 1992). Sulfate-reducing bacteria also have been shown
capable of degrading benzene (Ball and Reinhard, 1996; Coates, et al., 1996; Chapelle, et al. 1996; Weidemeier,
1996). Anaerobic processes may transform BTEX compounds to intermediates including phenols, organic acids, and
volatile fatty acids, before complete mineralization occurs (Reinhard, 1994).
Biodegradation of PAH Compounds
Microbes capable of biodegrading PAH compounds are found in most soils (Chapelle, 1993). Although PAH
degradation rates are greater under aerobic conditions, degradation also proceeds under anaerobic conditions
(Howard, et al., 1991). PAH biodegradation has been documented in bench tests and in the field (Wilson et al.,
1997; Arazzini et al., 1995).
BTEX compounds are more soluble in groundwater than PAH compounds, and therefore BTEX compounds are more
readily biodegradable due to their greater bi-availability.
BLASLAND. BOUCK & LEE, INC.-10/1/99 engineers A scientists A-6
AR3U271*
DRAFT
Attachment to Appendix G
Advection by Groundwater Flow (Constituent Migration Rate)
The average conservative linear groundwater velocity (advection rate) is based on Darcy's Law and can be defined
by:
Kiv - —
(D
where:
v = average linear groundwater (length/time);
K = hydraulic conductivity (length/time);
I = hydraulic gradient [length/length, (dimensionless)], which is defined as the piezometric head difference
between two points on a groundwater pathline divided by the distance between the two points; and
n, = effective or drainable porosity (volume of interconnected voids/total soil volume) of the soil, approximately
equal to the specific yield.
The migration rate of a dissolved constituent is usually slower than the average linear groundwater velocity due to
several mass-transfer processes, including hydrophobic sorption, which is approximated mathematically by a
retardation factor (R,,), a dimensionless parameter that represents the ratio of groundwater velocity to the actual
advection rate in a sorbing (onto immobile soil grains) porous medium. The migration rate of a dissolved constituent
can be approximated mathematically as (Freeze & Cherry, 1979):
BLASLAND, BOUCK & LEE. INC.~ 10/1*9 engineers A scientists A-7
A R 3 U 2 7 5
DRAFT
(2)
where:
vc = average migration rate of the dissolved constituent in groundwater; and
Rj = constituent retardation factor (dimensionless).
As shown by this equation, a high retardation factor results in a lower migration rate for the dissolved constituent
relative to the average linear groundwater velocity.
Hydrophobic Sorption
PAH and BTEX constituents are hydrophobic in nature and tend to be attracted to soil grains in the aquifer rather than
remaining dissolved in water. As indicated above, the retardation factor, R,,, represents the attenuation of a
constituent's center of mass migration due to sorption onto soil grains. Retardation must be considered in the
calculation of the time required for a constituent to reach a given downgradient location.
The retardation factor is defined by the following relationship (Freeze and Cherry, 1979):
Rd = I + 9bKd I ned rb d e (3)
where pb is the bulk density of the soil (mass/volume), ne is the effective porosity of the soil (volume of
interconnected voids/total soil volume), and K,, is the soil-water partition coefficient (volume/mass), often referred
to as the distribution coefficient. The soil-water partition coefficient (K,,) is the relative magnitude of the chemical
concentration on solid particles and in pore water for a particular soil (Lyman et al., 1982):
(4,
BLASLAND, BOUCK & LEE, INC.~ 10/1/99 engineers « scientists A-8
A R 3 U 2 7 6
DRAFT
where:
C, = concentration of the compound sorbed to the solid phase of the soil (mass chemical/bulk dry mass soil);
and
Cw = concentration of the compound in the pore water of the soil (mass/volume).
In this expression it is assumed that equilibrium exists between the solid and water phases; that temperature and pH
are constant; and that sorption is linear over the range of concentrations considered.
Hydrophobic sorption of PAHs and BTEX in groundwater depends on the amount of organic carbon naturally
occurring in the soil. For these constituents, K,, can be estimated from the measured fraction of organic carbon in the
soil, fx (grams organic carbon/gram dry soil), and the organic carbon sorption coefficient of the constituent, K^.
(5)
Hydrophobic sorption can be one of the primary processes affecting the migration rate of constituents in groundwater.
This method of estimating Kj provides a mathematical means to approximate retardation due to hyddrophobic
sorption.
BLASLAND, BOUCK & LEE, INC.-«<W/99 engineers A scientists A-9
A R 3 U 2 7 7
v>XHi\
Lif §
// *
,'--• MW-78,<-\~ MW-7AA -$l-|x 3.9^ ,.
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,///// /
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\
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// /
// /
/ /
nn
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//
NOTES:
1. MAPPING AND SAMPLE LOCATIONS BASEDON DATA PROVIDED BY WOOD WARD-CLYDE.APRIL, 1997.
2. CONTOURS ARE IN UNITS OF mg/L
LEGEND
MONITORING WELL LOCATION
TIDE-2•$• TIDAL MONITORING LOCATION
SITE BOUNDARY
WETLANDS BOUNDARY
GROUNDWATER DISSOLVEDOXYGEN CONCENTRATION CONTOURS
GRAPHIC SCALE
FORMER KOPPERS COMPANY, INC. NEWPORT SITE
NEWPORT, DELAWARE
NATURAL ATTENUATION APPENDIX
GROUNDWATER DISSOLVEDOXYGEN CONCENTRATION
BUSLAMO. BOUCK t LEE. INC.engineers A scientists
FIGURE
A-l
==.
NOTES:
1. MAPPING AND SAMPLE LOCATIONS BASEDON DATA PROVIDED BY WOODWARD-CLYDE.APRIL. 1997.
2. CONTOURS ARE IN UNITS OF ug/L.
LEGENQUW QA <L
*"-(p- MONITORING WELL LOCATION
TIOE-2^ TOAL MONITORING LOCATION
STE BOUNDARY
WETLANDS BOUNDARY
GROUNOWATER SUM OF NITRATEAND NITRITE CONCENTRATION CONTOUR
GRAPHIC SCALE
N 619.000
& 3a71SXO1.0»Cu ON---. orr.Rcr. CPMXSTANCAS
4/l/H SYW-M-CMS387ieiOO/M71«C02 DWC
A R 3 U 2 7 9 nn
FORMER KOPPERS COMPANY. INC. NEWPORT SITENEWPORT. DELAWARE
NATURAL ATTENUATION APPENDIX
SUM OF GROUNDWATER NITRATEAND NITRITE CONCENTRATIONS
BUSUMO. BOUCK* LEE. MC.engineers A scientists
FIGURE
A-2
