W912DR18R0055_-_Attachment_AM_-_June_2018_Planning_Meeting-Compressed.pptx

OU6 Remedy Optimization OU7 FTA 1 & 2 Property Line OU8 Pre-Design Investigation Defense Supply Center Richmond June 21, 2018

DEFENSE LOGISTICS AGENCY

AMERICA’S COMBAT LOGISTICS SUPPORT AGENCY

WARFIGHTER FIRST

D Guidance 26-Jun: Would like to see a refresh of this title slide. Should be able to see representation of all services and civilians (i.e. humanitarian effort). Director would like for us to bring him a few recommendations of possible design refreshes.

OU6 Off-site LWBU Remedy Optimization Objective:

Complete off-site activities and monitoring by 2025 Approach:

Actively remediate LWBU impacts through property line extraction (eliminate migration) and off-site extraction and reinjection Utilize extraction wells to redistribute TOC previously injected Use property line monitoring wells as compliance points to eliminate off-site activities.

OU6 LWBU TCE Contours

2014 TCE Contours 2017 TCE Contours EVO injected in most previously impacted wells prevent well sampling and plume contouring High concentrations measured in 2014 will require significant time to naturally attenuate

OU6 LWBU Optimized Remedy

Abandon off-site and property line MWs w/ EVO (~6 wells) DPT investigation to confirm GW concentrations in the LWBU (~3-4 locations) Reinstall select wells for performance monitoring Install off-site and on-site extraction and injection wells targeting property line LWBU impacts Extraction Well Injection Well

OU7 Site Map – All MW Locations

OU7 Site Map – Areas of Interest FTA-2 Area of Interest

FTA-1 Area of Interest 2017 TCE Plumes shown FTA-1 contours inferred based on historical data

OU7 FTA 1 Cross Section

OU7 Trend Plot – DMW-29A

OU7 Trend Plot – MW-150

OU7 Trend Plot – PZ-1

OU7 Trend Plot – PZ-4

OU7 Trend Plot – DMW-33A

2016 LWBU DPT Injections

FTA 1 Fenceline Area along FTA1 fenceline where DPT EVO injection was completed No space on downgradient side of the road to install new wells

DMW-22A

OU7 FTA 1 Fence Line Install new ISEB barrier with injection wells Repeated application of carbon needed to prevent off-site migration Abandon wells used to inject EVO Install replacement wells in select locations needed for performance monitoring

FTA-1 Conclusions and Path Forward DMW-29A screened below the mulch wall. Significant increase in concentration in MW-29A following mulch wall installation possibly desorption of mass due to installation activities.

Potential for significant mass not treated by ISEB remedy migrating to property line based on MW-150 data.

Remedial efforts to date successful in reducing parent compounds to daughter compounds (primarily cis-1,2-DCE and VC) Cis-1,2-DCE concentrations in off-site wells appears to be increasing since 2016 DPT EVO injection at property line Enhance remedy through installation of new ISEB barrier Abandon monitor wells used to inject EVO and replace select wells to continue performance monitoring.

OU7 FTA 2 Cross Section

OU7 Trend Plot – MW-83

OU7 Trend Plot – MW-84

OU7 Trend Plot – MW-148

OU7 Trend Plot – MW-149

FTA-2 Recommended Remedial Action Injection of semi-soluble carbon donor Barrier ~200 ft long ~12 ft wide barrier for minimum 100 day retention time (0.118 ft/day velocity) One transect injection wells on 30’ centers.

Wells installed in perimeter road Utilize bioaugmentation to overcome ISEB ramp up time Downgradient monitoring wells used as dose response and performance monitoring locations At least 5-6 years for mass to migrate through area based on historic data. At least one replenishment needed

FTA-2 Conclusions and Path Forward Historic concentrations from monitor wells MW-83 and MW-84 not treated by ISEB injections in 2013.

Migration of untreated mass into MW-148 and MW-149 possible Supplemental sampling should be conducted in 3-6 months to confirm elevated concentrations.

If confirmed, design and implement ISEB barrier in line with approved remedy

OU8 Pre-Design Investigation Objective to confirm extent and quantify CVOC impacts to support design of enhanced ISEB remedy under F-Bay 12 MiHPT points installed between May 22 and June 6, 2018 2 soil and 2 groundwater samples collected from 5 borings to aid in correlating MIP data from other borings.

OU8 Pre-Design Investigation – MiHPT and Sampling Locations

OU8 Pre-Design Investigation – Select Results

MiHPT-05 MiHPT-08 MiHPT-12

Saturated soil at 18.3-20’ bgs

OU8 Pre-Design Investigation – Analytical Results

Note: MiHPT-8 and -14 samples collected through temp PVC well w/ 5 ft screen. Sample depth noted represents depth of sample tubing.

OU8 Pre-Design Investigation - Conclusions MiHPT points show CVOC mass is present in both vadose and saturated zones beneath Building 65 F-Bay MiHPT successfully characterized extent of CVOC mass to target for remediation Analytical data collected from select MiHPT locations suggests concentrations in line with what’s been observed in down gradient monitor wells and no “hot spot” was identified.

Vinyl chloride observed in several locations suggest natural attenuation may be ongoing under F-Bay Planned enhanced ISEB combined with optimization of SSDS is an appropriate path forward image4.jpeg image5.png image6.jpeg image7.png image8.png image9.jpeg image10.png image11.png image12.png image13.png image14.png image15.png image16.png image17.png image18.jpeg image19.png image20.jpeg image21.png image22.png image23.png image24.png image25.png image26.png image27.png image28.png image29.png image30.png image31.png image1.jpeg image2.png image3.png