Abiotic / Biotic Treatability Study

Restoration Advisory Board Meeting

May 13, 2010

Installation Restoration Sites 26 and 28

2

IR Site 26 Treatability Study

Purpose of Treatability Test

Determine if combined abiotic/biotic treatment is a viable remedial alternative for mitigating the remaining chlorinated ethenes (CEs) present in the upper portion of the A-aquifer at IR Site 26.

Conduct Pilot Test in area of highest CE concentration in upper A-Aquifer at Site 26

Treatability Study Method:

Pilot Test Method:

Install wells in Pilot Test area

Determine baseline conditions in pilot test area

Inject EHC® into Aquifer

Measure Distribution of EHC®

Measure changes in pilot test area geochemistry

Measure changes in pilot test area CE concentrations

Biologically Mediated Oxidation - Reduction

Electron Donor Electron AcceptorResistor

Battery Ground

GrowthProtein Synthesis

Reproduction

CnHn

Fe(II)

H2S

H2

O2

NO3

As(V)

Mn(IV)

SO4

CO2

WorkLight bulb

Motors

Fe(0)

CO2 + H2O

Fe(III)

H2O +SO4

H2O

FeS2Fe (III)

Fe(II)

Fe(III)+SO4

H2O + CO2

HNO2

As(III)

Mn(II)

Fe (II)

S- + H2O

CH4

Reduced Oxidized Reduced Oxidized

Biological Reductive Dechlorination of Chlorinated Ethenes

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

H H H HH H

PCETCE

cis 1,2 -DCE

HH

H H HHHH HH H H

VC

H H

H H H H

Ethene

0

- 50

- 200

- 150

- 250

ORP

HHHHHH

C C C C C C

Ethane-300

PCETCE

cis 1,2 -DCEVC

EtheneEthane

PCETCE

cis 1,2 -DCEVC

EtheneEthane

HH

C CCl

Cl

Cl

Cl

Fe2+

TetrachloroetheneDichloroacetylene

Ethene

Ethane

Fe0Fe2+

Fe2+

Fe0

Abiotic Pathway

Fe2+

Fe2+

Fe0Fe0

Fe0

Fe0

O

O HH

O HH

O HH

O HH

O HH

O HH

O HH

Chloroacetylene

Acetylene

Some Hypothesized Reaction Pathways

Biotic Abiotic

PCE

TCE

cis 1,2-DCE trans 1,2-DCE

VC

Ethene

Ethane

PCE

TCE

VC

Ethene

Ethane

Chloroacetylene

Acetylene

1,1-DCE, trans 1,2-DCE, cis1,2-DCE

Dichloroacetylene

Hydrogenolysis

β-elimination

α-elimination

Hydrogenation

10

Indicators of Degradation Pathway

• Chloroacetylene

• Dichloroacetylene

Abiotic Pathway

• Acetylene

• 1,1-DCE

Biotic Pathway

• Primarily cis 1,2-DCE

• Low TCE, DCE, VC / ethene ratio• Stoichiometric Conversion

EHC Injection Process

GW FlowDirection

Groundwater Flow

Radius of EHC Distribution Evaluation

Groundwater Flow Direction

Relative Molar Fraction of Ethenes and Ethane

Upgradient Well

Treatment Area Wells

Relative Molar Fraction of Ethenes and Ethane

26

Preliminary Conclusions Site 26 TS

• pH, ORP, SC, T, in the treatment area are within the range considered appropriate for biotic and abiotic degradation of the CEs

• DO, nitrate, arsenic, manganese, iron, sulfate and methane reducing conditions have been established in the treatment area.

• Degradation of CEs is occurring.

• Cis 1,2-DCE stall is not occurring.

• Dechlorinating microbial culture (DHC) is present in the treatment area.

• Complete conversion of CEs to non-toxic degradation products is occurring.

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26 Treatability Study Schedule

June 28, 2010 – 4th Quarter GW Sampling Event

August 25, 2010 -Draft Treatability Study Results Technical Memorandum

October 27, 2010 -Final Treatability Study Results Technical Memorandum

28

Conduct Concurrent Pilot Tests in Three High Concentration Areas:

Evaluate Three Technologies:

In Situ Anaerobic Biotic/Abiotic Degradation (ISABA)

In Situ Anaerobic Biostimulation with Bioaugmentation (ISABB) Process

Building 88 Area

Traffic Island Area

Well W9-18 Area

Sodium Lactate & SDC-9

Emulsified Oil & SDC-9

Expanded Pilot Test (Site 28) Methodology

EHC

ISABA - EHC

ISABB - Emulsfied Oil & SDC-9

ISABB - Lactate & SDC-9

Task 1 Conduct MIPs Investigation

Task 2 Install Monitoring Wells

Task 3 Inject Substrates

Expanded Pilot Test Site 28

30

Site 28 Pilot Test Schedule

February 2010 - Work Plans Finalized

March 2010 - MIPs Investigation

May 2010 -Treatability Study Progress Report

July, 2010 - Substrate Injection

August 2010 to July 2011 - Performance Monitoring

October 2011 – Treatability Study Final Report

June, 2010 – Monitoring Well Installation