Remedial Investigation of Sediments in

NJDEP’s Site Remediation and Waste Management Program

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Nancy Hamill

Bureau of Environmental Evaluation and Risk Assessment

nancy.hamill@dep.nj.gov

609-633-1353 NJ Water Monitoring Council MeetingSeptember 21, 2016

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Presentation Outline: Remedial Investigation of Sediment

1. Objectives of a Sediment Remedial Investigation

2. Regulatory Background

3. Sediment Sampling, Analysis, QA/QC Plan Design

4. Sediment Screening Criteria for Data Evaluation

5. Site-Specific Risk-Based Remediation Goals

1. Objectives of a Sediment Remedial Investigation

To determine:

• if site contaminants have migrated from site to surface

water body

• if contaminants are present above NJSWQS and

sediment screening criteria

• Nature and extent (horizontal and vertical) of discharged

contaminants

• if unacceptable risk to aquatic-dependent receptors

If “yes” to all, remediate sediment to protective levels

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2. Regulatory Background

• NO PROMULGATED SEDIMENT STANDARDS!

• Sediment remediation goals determined on case-by-case basis in accordance with:

- Brownfield and Contaminated Site Remediation Act, N.J.S.A. 58:10B-1 et seq.

- Spill Compensation and Control Act, 58:10-23.11.

- NJDEP Technical Requirements for Site Remediation N.J.A.C.7:26E, May 2012

- Ecological Evaluation Technical Guidance, (EETG) February 2015

available at: http://www.nj.gov/dep/srp/ 4

N.J.A.C.7:26E-1.16, 3.6

and

Ecological Evaluation Technical Guidance

Identify co-occurrence of:

● Environmentally Sensitive Natural Resources (ESNRs) on, adjacent, under influence of the site,

● Contaminants of Potential Ecological Concern (COPECs)- soil contaminant concentrations on-site are

greater than ecological (sediment) screening criteria (ESC), and

● Contaminant Migration Pathways to ESNR (pipe

outfall, ditches, swales, creeks, groundwater, direct discharge)

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N.J.A.C.7:26E-4.8 and Ecological Evaluation Technical Guidance

Remedial Investigation of Ecological Receptors:

• Delineate horizontal/vertical extent of site-related contamination in all media, including surface water and sediment, to the NJSWQS and sediment screening criteria (background, if higher)

• Conduct an Ecological Risk Assessment to verify risk and determine site-specific risk-based sediment remediation goals

• Remediate to site specific remediation goal, sediment screening criteria, or background

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Contaminant Migration Pathway Example

LCP Superfund Site, Linden, NJ

Hg process waste → outfall pipe → South Branch Creek →

Arthur Kill

Contaminant Migration Pathway Example

Lail Property Site, Paulsboro, NJ

Direct disposal of PCBs into Mantua Creek Embayment 9

3. Sediment Sampling, Analysis,QA/QC Plan Design “musts”

• Biased toward areas of suspected contamination/depositional areas to identify contaminant sources, gradients, hot spots

• Minimum of two depths (0-6” plus one other; if VOAs, 6-12” is first interval)

• Discrete samples (no composites)

• Total Organic Carbon, particle grain size

• Analyte lists: Priority Pollutant, Target Compound List Organics/Target Analyte List Metals from CERCLA, or SW846 List from RCRA; PCB congeners (USEPA Method 1668A/B) and Dioxin (USEPA Mehtod1613B) for sample subset

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3. Sediment Sampling, Analysis,QA/QC Plan Design “musts” (con’t)

• Co-located surface water samples close to sediment interface

• Background locations for sediment and surface water required

- locations near study site with concurrent data collection

- regional databases, e.g., Division of Water Monitoring and Standards

• Data must be validated; always report detection limits

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4. Sediment Screening Criteria forData Evaluation

NJDEP Ecological Screening Criteria

(ESC) Table, updated March 10, 2009http://www.nj.gov/dep/srp/guidance/ecoscreening

Sediment Screening Values “Foundation” Datasets:

1. Freshwater Lowest Effects Levels (LEL) and Severe Effect Levels (SEL) Ontario Ministry of the Environment, Persaud, et al., 1993

2. Marine/Estuarine Effects Range-Low (ER-L) and Effects Range-Median (ER-M) Long et al., 1995

● Large number of studies correlate adverse effects to sediment macroinvertebrates to bulk sediment contaminant concentrations

● LEL / ER-L: adverse impacts to sediment benthos in approximately 10% of studies

● SEL – adverse impacts in approximately 95% of studies

● ER-M – adverse impacts in approximately 50% of studies

Comparison of Sediment Data to Sediment Screening Criteria

● LEL/ER-L are the sediment screening criteria; SEL/ER-M are

provided as frame of reference

● Screening criteria do not address bioaccumulation –Persistent biomagnifying contaminants indicate potential wildlife risk; conduct additional site-specific evaluation

● Compare maximum and mean site-related data with sediment screening criteria

● Exceedences indicate potential for adverse ecological effects and more rigorous biological tests may be needed (sediment toxicity test, benthic community surveys, tissue analysis)

● Alternate or new sediment screening criteria (for contaminants w/o table values) can be proposed

● Contaminants w/o sediment screening criteria must be

carried through the ecological risk assessment process

Comparison of Sediment Data to Sediment Screening Criteria (con’t)

● If more than one sediment screening criteria, generally use most conservative

● Where analytical detection limits are higher than sediment screening criteria (e.g., PAHs), retain contaminant and use estimated concentrations for comparison

● Professional judgment for marginal exceedence of one or a few sediment screening criteria (e.g. Lead, PAHs in urban waterways); consider TOC where exceedance are “borderline”

● Sediment screening criteria used in SRWMP and throughout USEPA Region 2 site remediation programs

● PAHs, metals, pesticides, PCBs are “top” contami-nant classes that exceed sediment criteria state-wide 16

5. Site-Specific Risk-Based Sediment Remediation Goals

● Sediment benthic macroinvertebrates:

- Sediment toxicity tests for concentration-response models over concentration range

- Equilibrium Partitioning Sediment Benchmarks (USEPA 2003, 2005, 2008) – determine sediment concentration that provides pore water at aquatic toxicity benchmark; use sample-specific TOC/AVS

● Aquatic-dependent wildlife (birds, mammals):- Back-calculate from food chain models with site-specific

prey tissue data

● Fish, larger macroinvertebrate:- Calculate using “critical body residue” (aka tissue residue

effects levels)

See Ecological Evaluation Technical Guidance for sample calculations17

Receptors of

Interestvs

Prey Sampled

Example: Calculation of Site-Specific Sediment Remediation Goal for Piscivorous Wildlife

1. Calculate site-specific “sediment-to-biota-accumulation factor” , BSAF

BSAF = Cprey tissue / Csediment ; Ctissue = C sediment x BSAF

2. Dosetot = (C prey tissue)(.9)(IR)/BW (e.g., great blue heron)

Set desired dose equal to literature based NOAEL and substitute “C sediment x BSAF” for C tissue:

3. NOAEL = [Csediment x BSAF](.9)(IR)/BW

4. Solve for “safe” sediment concentration:

C sediment, mg/kg= NOAEL x BW

BSAF x .9 x IR

Program Needs

• Update Table!

• Increase use of sediment pore water sampling and comparison with water quality criteria for screening

• Increase use of Equilibrium Partitioning approach to determine site-specific sediment benchmarks

Questions?20