Results of HRC Injection at Dixie Cleaners, Jacksonville Florida

Transcription

1 Results of HRC Injection at Dixie Cleaners, Jacksonville Florida

2 Hydrogen Release Compound (HRC TM ) Used to enhance in situ biodegradation by supporting anaerobic reductive dechlorination process. HRC is a proprietary polylactate ester that, when injected into the groundwater, slowly releases lactate. Lactate is metabolized by naturally occurring microorganisms, resulting production of hydrogen. Microorganisms use the hydrogen to progressively remove chlorine atoms from the chlorinated hydrocarbon contaminants. converting PCE > TCE > DCE > vinyl chloride >ethene

3 Assessment Information Contaminant Assessment Report completed in Dec.1998 Reductive dechlorination ongoing High contaminant concentrations located near sewer line Depth to water: less than 2 feet bls Plume Size: approximately 1 acre (defined by MCLs) Highest concentrations at: feet bls Deepest Contamination: 33 feet bls

4 Highest contaminant concentrations: - PCE 935 µg/l TCE 12,700 µg/l cis 1,2-DCE 22,400 µg/l Vinyl Chloride 6,900 µg/l This Site has a total of 30 monitoring wells: 11 shallow zone (10 to 12 ft bls) 10 in the intermediate zone (20 to 22 ft bls) 9 deep zone (30 to 32 ft bls)

5 Remediation Scenario 2 Injections have been completed: 1st Injection- June days to complete 175 points, 22,000 lbs of HRC TM Depth of injection: 25 to 30 ft bls Size: 200 ft x 100 ft Volume: 5lb./ft of vertical saturated zone 2nd Injection- April days to complete 52 points, approximately 3,000 lbs of HRC TM Size 80 ft x 60 ft Volume: 3lb/ft to 7lb./ft of vertical saturated zone

6 Injection Grid, June 2000

7 Rupe Pump

8 Geoprobe 66DT Rig

9 HRC Injection Process

10 HRC June 2000 HRC April 2002

11 HRC, April 2002

12 Shallow Interval MW028 Source Area Well (ug/l) 12,000 10,000 8,000 6,000 4,000 2,000 0 Apr-00 Jul-00 Oct-00 Jan-01 Apr-01 Jul-01 PCE TCE cis 1,2-DCE trans 1,2-DCE Vinyl Chloride

13 Deep Interval MW030 Source Area (ug/l) Apr-00 Jul-00 Oct-00 Jan-01 Apr-01 Jul-01 PCE TCE cis 1,2-DCE trans 1,2-DCE Vinyl Chloride

14 Intermediate Interval MW029 Source Area Well (ug/l) 40,000 35,000 30,000 25,000 20,000 15,000 10,000 5,000 0 Apr-00 Jul-00 Oct-00 Jan-01 Apr-01 Jul-01 PCE TCE cis 1,2-DCE trans 1,2-DCE Vinyl Chloride

15 Summary of TCE reduction in key monitoring wells: MW April 2000 July 2001 % Reduction MW007 2, % MW % MW % MW029 10,100 1,420 86% MW032 12, %

16 Results- Groundwater Chemistry Elevated concentrations of chloride relative to background, Low dissolved oxygen and negative redox continue Rapid increase in TOC may indicate an additional carbon source (sewer line leak) Lactic acid breakdown products found indicating that HRC continues to dissolve within the aquifer

17 General Observations Reductive dechlorination process is occurring within the aquifer at a much more rapid pace than would occur under natural, non-induced conditions. PCE has nearly completely degraded at the site. PCE was only detected in two monitoring wells at concentration of 38 µg/l and 42 µg/l. TCE continues to degrade in the in the shallow, intermediate and deep zones. DCE and vinyl chloride continue to accumulate. Downgradient migration of the contaminant plume does not appear to have occurred.

18 Cost: 1st Injection Well Installation & Baseline Sampling: $30,000 HRC Product: $150,000 HRC Injection: $80,000 Monitoring, Reporting & IDW: $30,000 Total 1st Injection: $290,000 2nd Injection $53,000

19 Current Status: Post injection Sampling will be conducted in May 2002 Lessons Learned: Complete delineation of underground utilities Inform all property owners concerning the extent of injection activities and coordinate with site property owners to ensure uninterrupted access to the property. Sufficient soil sampling was not conducted; additional soil sampling will be necessary for full site remediation. A thorough understanding of site geochemistry is required to understand effect of HRC TM on groundwater. Recommend utilizing HRC TM vendor for onsite supervision of injection.