SUCCESSFUL APPROACH TO PCE REMEDIATION

Transcription

1 SUCCESSFUL APPROACH TO PCE REMEDIATION ACTIONS TAKEN AND PATH FORWARD INTERNATIONAL FABRICARE INSTITUTE Tech Road, Silver Spring, Maryland

2 SCALE: FEET Commercial Park Layout N OOO NNN INTERNATIONAL FABRICARE INSTITUTE PARCEL A BROADBIRCH DRIVE WSSC PROPERTY ALLEGANY GGG B N OUR EFI EL D III KAISER PARCELS WAY TECH ROAD SAFETY KLEEN FFF SOMERSET LLL KKK JJJ WSSC SEWERLINE

3 BACKGROUND IFI property located in WestFarm Commercial Park In 1992, WestFarm Associates performed Phase I environmental inspection on adjacent tract (Parcel A) in advance of selling property PCE (0.3 to 1.2 ppm) detected in groundwater at Parcel A Groundwater investigations conducted on IFI and other commercial park properties to define the nature and extent of contamination Principal source of contamination determined to be IFI sanitary sewer lateral and the Washington Suburban Sanitary Commission (WSSC) sewer trunk line

4 BACKGROUND (cont.) WestFarm sued IFI and WSSC raising Superfund, nuisance, and trespass claims July 1993, Maryland District Court issued summary judgment against IFI and WSSC on the Superfund claim July 1993, Jury ruled against IFI and WSSC for negligence claim IFI entered into Administrative Consent Order with Maryland Department of Environment (MDE) in 1996 Due to other potential legal actions by downgradient property owners, hydraulic containment strategy adopted (Pump & Treat) on IFI and Parcel A properties

5 Regulatory History and Actions Performed Order Required and Parties Implemented: Supplemental groundwater investigation Module 1 and 2 vacuum-enhanced groundwater recovery and treatment on IFI and Parcel A. Removal or repair of IFI s leaking sanitary sewer lateral. Groundwater monitoring program to track changes in water chemistry with time. IFI required to Achieve Drinking Water Standard for PCE (5 ppb)

6 Remediation System Layout Divested NPDES Outfall Treatment System Parcel A IFI Recovery Wells

7 Groundwater Basin IFI Groundwater Basin

8 Groundwater Flow Conditions IFI HYDRAULIC CONTAINMENT Groundwater Flow DILUTION / DISPERSION Creek

9 Monitoring System 47 groundwater monitoring and/or recovery wells Quarterly-Water level measurements from all wells/piezometers 22 wells sampled quarterly On third quarter every year, an additional 14 wells sampled Reports submitted to MDE on quarterly basis

10 OBSERVATIONS Small groundwater basin, highly oxygenated Negligible degradation products (cis( cis-1,2 DCE); Purely a PCE plume Highest historical concentration on IFI ~12 ppm, average concentration ppm Parcel A concentration ~ 0.5 ppm Farther downgradient ~ 0.03 ppm Discharge point ~ small stream

11 OBSERVATIONS (cont.) Significant decrease in groundwater concentrations (PCE) since system startup in 1998 Observed typical asymptotic curve on mass removal in groundwater and vadose zone P&T technology is incapable of achieving MCLs in groundwater Other available technologies/approaches can provide equal or better results as P&T

12 Conditions-FY1998 PCE in Groundwater MW-10 OOO N KAISER NNN INTERNATIONAL FABRICARE INSTITUTE GM-4 TECH ROAD MH ppb X X GM-1 GM-2 GM-7 X X X X XX XX XX X MH-2 MH-3 SAFETY KLEEN MW-3 GM-3 GM-5 GM-6 SK-5 PARCEL A SK-1 MW-2 X X XX X MH-5 SK-2 MW-1 X X SK-7 SK-3 SK-6 DW-1 BROADBIRCH DRIVE MW-1 SK-4 SCS-2A SCS-2B SCS-1A SCS-1B DW-3 MW-2 MW-8 ALLEGANY SCS-3A SCS-3B WSSC FFF MW-6 SOMERSET MW-5 GGG B N OUR EF D MW-7 DW-2 I E L KPS-2S III

13 Conditions-FY2002 PCE in Groundwater MW-10 OOO N KAISER NNN INTERNATIONAL FABRICARE INSTITUTE GM-4 TECH ROAD MH ppb X X GM-7 GM-1 GM-2 X X X X XX XX XX X MH-2 MH-3 SAFETY KLEEN MW-3 GM-3 GM-5 GM-6 SK-5 PARCEL A SK-1 MW-2 X X XX X MH-5 SK-2 MW-1 X X SK-7 SK-3 SK-6 DW-1 BROADBIRCH DRIVE MW-1 SK-4 SCS-2A SCS-2B SCS-1A SCS-1B DW-3 MW-2 MW-8 ALLEGANY SCS-3A SCS-3B WSSC FFF MW-6 SOMERSET MW-5 GGG B N OUR EF D MW-7 DW-2 I E L KPS-2S III

14 TOTAL VOC Mass Removal 1.4 Figure 10 Combined Groundwater Treatment System and SVE System Total VOCs Mass Removal 1.2 Total VOCs Mass (lbs/day) Calculated Treatment Cost: $7,625 per lb. PCE /5/1998 7/24/1998 2/9/1999 8/28/1999 3/15/ /1/2000 4/19/ /5/2001 5/24/ /10/2002 Date

15 If IFI identifies cost-effective innovative technology that may give equal or superior results, MDE agrees to consider any request by IFI to modify Order for implementation of alternative. Administrative Consent Order-MDE/IFI October 7, 1996

16 MDE agrees to consider a petition from IFI to adopt an alternative groundwater treatment standard provided 1) MCL for PCE has increased or 2) MDE policies no longer require achieving MCL. Administrative Consent Order-MDE/IFI October 7, 1996

17 SURROUNDING LAND USE, RISK, AND CLEANUP INCREASING RISK OF EXPOSURE Residential Commercial Industrial DECREASING CLEANUP ENDPOINT GOAL

18 Path Forward-MDE Approved Interim shutdown of P&T system (2 years) Ability to utilize site-specific specific risk analysis to establish alternative cleanup goals (Not MCLs) Performance of flow-transport modeling and human/ecological risk analyses Evaluation of alternative approaches Monitored Natural Attenuation (MNA) MNA with hot-spot treatment (in-situ reductive dechlorination)

19 CONCLUSIONS P&T Technology is not capable of achieving MCL Use limited to hydraulic containment Site-specific cleanup goals (based on risk analyses) should be considered based on actual exposure pathways In many cases, use of MCL as cleanup goal is overly conservative Other techniques other than P&T are available which provide adequate environmental protection Monitored Natural Attenuation (MNA) In-situ technologies coupled with MNA

20 Some IFI Observations

21 The Site as First Identified Drycleaning plant operation from Research Center operation & IFI Headquarters from One hot-spot at ~ 5 ppm above sanitary sewer house connection, known to be former location of dumpster. Immediately downstream & adjacent to sewer line, concentrations were ~5-7 ppm.

22 Discharges at IFI Site No records/knowledge about discharges from drycleaning operations from From , no discharges to sewer from leaks or spills (e.g., from drycleaning equipment) Small aliquots from Karl Fischer titrations from lab, on the order of ~200 ml/week discharged to sewer, along with minimal quantities of separator water. With dilution from commercial washers used for testing, concentration at sewer house connection were in the range of ~3 10 ppb.

23 Source of Contamination? As measured by Arcadis, plume length groundwater flow rate = an initial discharge of perc at ~34 years ago i.e. in Coincidentally, 1969 was the first year of operation for the cleaning plant at this site. As previously noted, it is known that there were no discharges of perc from 1974 to 1991 other than the lab aliquots and from separator water (i.e., there were no drycleaning system leaks or spills)

24 OBSERVATIONS & CONCLUSIONS Mass quantity of perc recovered far outstrips total mass of lab aliquots (in low ppb range), or from minimal separator water discharges (at ~150 ppm). With laundry water discharges from IFI s textile testing at 1,000+ gallons/day, even separator water should have been at ~15 ppb at the sewer lateral; actual levels were 5,000 7,000 ppb. IFI contamination resulted from an unknown spill in 1969 from the drycleaning plant. Similarly, the mass of perc present at most sites indicates that spills have almost certainly been the source.