Presentation Overview

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Project Objectives

Technical Approach

Preliminary Results

Remaining Work

Questions

Supplemental investigation is needed to:

1) Further delineate PCE & daughter products (TCE,DCE, & VC) in A-aquifer within & around the FormerBuilding 88 & Traffic Island source areas

2) Confirm depth & lateral continuity of A/B-aquitard inTraffic Island Area

3) Verify depth to top of B2-aquifer in Traffic IslandArea

4) Confirm whether existing well W-88-1 is screened inB2-aquifer

5) Confirm whether B2-aquifer beneath Traffic IslandArea is impacted by COCs

Project Objectives

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Phase 1 – Semi-quantitative ScreeningSurvey

To further assess the distribution of CEs andsoil lithology in the areas of interest

Phase 2 – Monitoring Well Installations &Sampling

To fill in data gaps of the current groundwatermonitoring well network

Technical Approach

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Navy SCAPS Rig

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SCAPS Probe

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From:

U.S. Army Corps of Engineers, 2002,

Cost and Performance Report for Tri-Service

SCAPS MIP, January , ERDC/EL TR-02-1

Membrane interface probe (MIP)/ Direct sample ion-trapmass spectrometer (DSITMS) detector System

Semi-quantitative COC concentration data(mg/L of calibration solution)

MIP data are only considered estimates(USACE, 2002)

<http://el.erdc.usace.army.mil/elpubs/pdf/trel02-1.pdf>

Results by MIP system are relative & should beverified by soil and groundwater samples(EPA, 2012)

<http://www.clu-in.org/characterization/technologies/mip.cfm>

MIP/DSITMS System

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SCAPS Test Results – Former Bldg 88

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Maximum MIP/DSITMSResponse & Groundwater

and Soil Results

PCE

~6 to 16 ft bgs(Fine-grained Sediment Interval)

GeneralGroundwaterFlow Direction

11.5 ft bgs830,000 µg/Lcs – MIP660 µg/L - GW8.8 mg/kg - Soil


µg/Lcs denotes micrograms perliter of DSITMS calibration solution

Tier 2 SCAPS test location



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18 ft bgs50,000 µg/Lcs – MIP78 µg/L - GW1.9 mg/kg - Soil


and Soil Results

PCE

~16 to 27 ft bgs(Coarse-grained Sediment Interval)

µg/Lcs denotes micrograms perliter of DSITMS calibration solution




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GeneralGroundwaterFlow Direction Tier 2 SCAPS test location



and Soil Results

PCE

~27 to 40 ft bgs(Fine-grained Sediment Interval)


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and Soil Results

PCE

~40 to 56 ft bgs(Coarse-grained Sediment Interval)




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and Soil Results

PCE

~56 to 70 ft bgs(Coarse & Fine-grained

Sediment)



1) SCAPS results generally correlate well with historical data

2) MIP/DSITMS detections of PCE primarily in fine-grained sediments

3) Highest MIP/DSITMS detections of TCE & DCE primarily in fine-grained sediments

4) Vinyl chloride was not detected in any of the MIP/DSITMS samples

5) Fine-grained sediments acting as a continuing source of chemicals tothe groundwater

6) MIP/DSITMS responses are over 10-times higher than collocateddiscrete depth groundwater sample results

7) Discrete depth groundwater results are 10-times lower thanestimated effective solubility limits

8) Discrete depth soil results are over 10-times lower than estimatedsoil saturation concentrations

Preliminary Findings

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Potential Well LocationsFormer Bldg 88 Area

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New Monitoring Well

Planned SCAPS LocationsTraffic Island Area

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0 to 23 ft bgs


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23 to 46 ft bgs


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46 to 65 ft bgs

Planned Well LocationsTraffic Island Area

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Tier 2 SCAPS at Former Bldg 88 Area – Spring 2013

Tiers 1 & 2 SCAPS at Traffic Island Area – Spring 2013

Monitoring Well Installations – Summer 2013

Groundwater Sampling – Summer & Fall 2013

Field Work Timeline

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Questions?

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Point of Contact:

Scott Anderson

BRAC Environmental Coordinator

(619) 532-0938

[email protected]

Site 28 Supplemental Investigation

Education

Transcript of Site 28 Supplemental Investigation