601 S. Madison Avenue, Suite 60

Monroe, GA 30655

Office: 678-635-7360/Cell: 770-241-6176

Prepared by:

Eden Remediation Services Kenneth Summerour, P.G.

ken@edenremediation.com

www.edenremediation.com

Overview

Remedial Technologies

Subsurface Injection Techniques

Soil Blending Methods

Case Studies

Overview of Remedial Technologies

Chemical Oxidation (ISCO)

Chemical Reduction (ISCR)

Enhanced Bioremediation (ISB)

Surfactant Applications

Chemical Oxidation (ISCO)

4

Breaking bonds of organic

molecules and inserting oxygen

End products are carbon

dioxide, water, and harmless

salts

ISCO applied via direct push

rod train, injection wells,

or blending methods

Useful on source areas or full scale treatments

Success requires

contact with contaminated media (both

saturated soils and impacted groundwater)

Common Chemical Oxidants

Fenton’s Reagent – H2O2 + Fe+2 OH- + OH- + Fe+3

Catalyzed Hydrogen Peroxide (iron chelation)

Calcium Peroxide/Modified Fenton’s (iron chelation + acidic modifier)

Sodium Persulfate – S2O8-2 + activator SO4

.- + (SO4 .- or SO4

-2)

Sodium and potassium permanganate (ideal for chlorinated ethenes)

Ozone (gas, requires ozone generator)

Chemical Reduction (ISCR)

6

ISCR involves the addition of electrons-

mirror image of

ISCO

Abiotic reactions usually

result in less daughter product

formation

Used on chlorinated plumes, metals, explosives,

etc. Applied via direct injection and solid phase PRBs (goal of developing

reducing zones)

Examples: ZVI, nZVI,

iron sulfides, polysulfides, dithionites,

etc.

Enhanced Bioremediation (ISB)

7

ISB involves the injection or addition of nutrients to stimulate microbial

degradation

Petroleum hydro-

carbons commonly reduced

aerobically

“Treatment Train”: ISCO +

aerobic bio-stimulation

Sulfate reducing bacteria - petroleum

fuels or add iron for

treatment of chlorinated

VOCs

Chlorinated VOCs treated

anaerobically reductive de-chlorination

(lactate, soybean oils,

etc.)

Surfactant Treatments

8

Surfactants are soluble in both oil (fuel) and

water

Used for NAPL

removal by creation of emulsions

Extraction required following emulsifi-cation

Variety of surfactant products available

depending on type of

NAPL

Follow-up monitoring needed to

ensure surfactant impact & removal

Comparison of Remedial Technologies

Speed of reaction: ISCO – ISCR – ISB

Source area treatments: ISCO or surfactants

ISCO can treat NAPL and higher dissolved

Large plumes – ISCR/ISB more cost effective

Treatability testing aids in comparison

Consider multiple technologies

Subsurface Injection Technologies

Direct Push Injection

Target discrete zones

Allows higher pressure injection (ZVI/slurries)

Difficult in “tight” formations/surfacing

Additional wells often needed for monitoring

Injection Wells

Constructed with PVC, CPVC, Stainless Steel

Grout seals – better in “tight” formations

Easier geochemical monitoring

Facilitates multiple point injection

Cost savings with multiple injections

Successful Injections Require:

Source area characterization/vertical contaminant profile

Good estimate of pore treatment volume

Direct contact (especially ISCO/surfactants)

Delivery method suited to site conditions

Sufficient delivery volume/don’t under dose

Measure contact in the field!

Soil Blending Methods: In-Situ

In-Situ blending performed using excavators or augers

Offers maximum contact

Eliminates waste generation

Treat soils AND groundwater together

Allows treatment of low permeability soils

“Green friendly” alternative to off-site land filling

Soil Blending Methods: Ex-Situ

Ex-situ blending involves removal prior to treatment

Soils typically screened and blended in a pug mill

Soils can be stabilized after treatment for re-use

Lower cost alternative to hazardous waste landfilling

Select Case Studies

1) VCP Soil Blending Site (AL)

2) Dry Cleaner – Texas

3) Wood Treatment Facility

(South GA)

4) Industrial Site (Atlanta area)

5) Former Lagoon (Upstate NY)

6) Former Auto Dealer (NW GA)

Alabama VCP Site – Soil Blending Overview

Releases - former paint solvent ASTs

Assessment identified LNAPL and

VOCs (naphthalene and toluene)

Highest total VOCs: 1,000-5,000 ppm

ADEM required haz disposal- blending

offered as an alternative

Treatability study identified CHP +

sodium persulfate + iron chelate

Treatment performed on 300+ tons of

soil from 2-10’

Confirmatory sampling indicated VOC

reduction to below risk target levels

No costly offsite removal required

Cost < $75,000, NFA received

VCP Site (cont.) Soil Blending Results

0

100

200

300

400

500

600

700

800

900

1,000

Baseline Post Blending

So

il C

on

ce

ntr

ati

on

s (

mg

/kg

)

PRE AND POST SOIL BLENDING RESULTS

4-Methyl-2-Pentanone

Ethylbenzene

Isopropylbenzene

Methylcyclohexane

Naphthalene

Tetrachloroethene

Toluene

Xylenes (total)

Former Dry Cleaner - Montgomery Co., Texas

• Release of PCE and daughters, max VOCs >1,000 ppb

• DTW 20-30 ft-bgs, water bearing silty-sand confined by

SC/clay

• PCE degradation products suggested past reductive

de-chlorination

• Risk based treatment goal: < PCLs (protective

concentration limits)

Overview

Former Dry Cleaner - Montgomery Co., Texas

• ISCO treatment designed utilizing iron activated

sodium persulfate (15-20% solution)

• Three injection treatments performed targeting

source area and down-gradient

• Confirmatory sampling indicated results <PCLs

• A NFA later received allowing redevelopment

Results

Wood Treatment Facility Overview

Site in Coastal Plain Province

near Okefenokee Swamp

Creosote and penta-

chlorophenol (PCP) impact in

surface impoundment

NAPL present & dissolved

PAHs to 45-55’

Proposed Corrective action

includes ISCO-soil blending &

down-gradient PRB

Former

Impoundment

Site

Wood Treatment Facility (cont.) Treatability Approach

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

Control 15% H2O2 15% H2O2 and 0.1% PMG

TREATABILITY RESULTS Anthracene

Benzo(a)pyrene

Chrysene

Fluoranthene

A treatability study indicated either soil blending or ISCO

would be most effective using CHP followed by potassium

permanganate

Wood Treatment Facility (cont.) Soil Blending

An initial soil blending pilot in 2010 resulted in NAPL removal from

CHP-permanganate oxidation

Follow-up pilot in 2012 used high volume dose of CHP only with

significant reduction observed < target goals

Full scale treatment pending following PRB installation

Industrial Facility Overview

22

A small PCE solvent plume was identified in

an industrial park outside Atlanta, GA

Maximum PCE concentrations - 260 ppb

Iron-rich saprolite at a depth of 15-25 feet

Goal was PCE reduction < MCL (5 ppb)

Treatability study indicated sodium

persulfate with natural iron activation

most effective

Injection performed into 15 delivery

wells

Industrial Facility (cont.) Treatment Results

Post Injection Pre Injection

Confirmatory sampling conducted 45, 90, and 120 days

post injection indicated non-detect concentrations of

PCE and degradation products after a single injection

Former Lagoon, Upstate NY Overview

IW

-1

IW

-2

IW

-3

IW

-5

IW

-4

Lagoon

Well 2

Lagoon

Well 1

Site contains two former solvent

disposal lagoons (1,1,1-TCA, DCE

etc.)

Limited soil excavation performed in

the source area

Groundwater pump-and-treat

system installed

VOCs detected in alluvial sediment

and fractured sandstone formation

(15-20 feet)

Former Lagoon (cont.) Treatment Process

25

ISCO treatment performed

using alkaline activated

persulfate to lower source

area VOCs (1,000-5,000 ppb)

Geochemical monitoring

indicated significant oxidant

impact (see graph)

Confirmatory sampling

indicated VOC reduction

Further treatment is pending

Former Auto Dealer Overview

Auto dealership constructed in low lying swamp

Valley and Ridge Province, Conasauga Formation

(limestone)

Groundwater depth 4 -13 ft-bgs in silty-clay/sandy-silt soils

Site

Separate releases of

gasoline and waste

oil/chlorinated VOCs

discovered, plume >200’

LNAPL detected in 22

wells, thicknesses >1’

Former Auto Dealer (cont.) Geologic Cross-Section

Former Auto Dealer (cont.) ISCO Treatment Summary

ISCO injections performed using CHP and activated persulfate

Separate ISCO injection performed using potassium

permanganate to treat vinyl chloride

Results indicated complete LNAPL removal and desired

reduction in dissolved phase

Leading edge of plume

treated/controlled

Vinyl chloride eliminated

with one injection

NFA achieved allowing

sale of the property

Former Auto Dealer (cont.) MW-10: south end under building

Subsurface Remediation is Attainable! Keep at it, and remember to:

Start with a good estimate of clean-

up mass and volume

Choose the right chemistry –

treatability testing is always

recommended

Design a “best-fit” strategy

(i.e. soil blending, injection, and

down-gradient PRB)

Measure contact in the field

Follow a performance monitoring plan to expedite site

closure

Eden Remediation Services Services We Offer

Chemical Injections (ISCO/ISCR)

Enhanced Bioremedial Approaches

Surfactant Applications

PRB Design and

Implementation

Remedial Design/System

Optimization

Rapid Closure Strategies