Description
Historical activity that resulted
in contamination.
| The drycleaner facility operated from 1963 until 1992. The facility had two drycleaning machines. The site is part of a large, single story retail strip mall located on a 32 acre site. PCE was the only drycleaner solvent used at the facility.
The contamination sources are located under the former drycleaning facility in the area of the drycleaning machines and waste recovery still in the northeastern area of the site, in the rear of the suite. There are no municipal water wells within one mile of the site, nor are there any private drinking wells within a one mile radius of the site. Remediation Status: In groundwater monitoring |
Contaminants
Contaminants present and the highest amount
detected in both soil and groundwater.
| Contaminant |
Media |
Concentration (ppb) |
Nondetect |
| 1,1-Dichloroethene |
groundwater |
|
|
| Tetrachloroethene (PCE) |
groundwater |
|
|
| Tetrachloroethene (PCE) |
soil |
|
|
| Trichloroethene (TCE) |
groundwater |
|
|
| Trichloroethene (TCE) |
soil |
|
|
Site Hydrology
| Deepest Significant
Groundwater Contamination: |
|
|
| Plume Size: |
|
|
| Average Depth
to Groundwater: |
|
24ft |
Lithology and Subsurface Geology
|
|
brown to gray silty clay and clayey silts
Depth: 0-27ft bgs
27ft thick
Conductivity: 0.002834646ft/day
Gradient: 0.0002ft/ft
|
|
|
medium to coarse sand and gravel
Depth: 27-30ft bgs
3ft thick
|
|
|
silty clay
Depth: 30-34ft bgs
4ft thick
|
|
|
brown to gray sandy silt which becomes more granular with depth
Depth: 34-53ft bgs
19ft thick
|
|
|
coarse tan sand and gravel
Depth: 53-54ft bgs
1ft thick
|
|
|
brown to gray silty clay
Depth: 54-58ft bgs
4ft thick
|
Pathways and DNAPL Presence
 Groundwater
 Sediments
Soil
DNAPL Present
|
Vapor Intrusion Pathway
Has the potential for vapor intrusion (VI) been evaluated? |
|
No
|
Has a vapor mitigation system been installed? |
|
No |
Additional VI Information: |
|
The VI Pathway was not evaluated due to the on-going remediation and also the suite and adjoining suites are currently unoccupied. |
Remediation Scenario
Cleanup
Goals: |
|
To achieve drinking water standards, with an interim goal of plume contraction.
|
Remedy Level: |
|
Full Scale Remedy |
Technologies
In Situ Biostimulation |
|
Why the technology was selected:
EZVI was chosen for the treatment of the shallow soil contaminated with PCE. EZVI was chosen to treat the hot spots present in the vadose zone under the facility.
Biostimulation and abiotic reductive dechlorination was chosen for the saturated zone due to the presence of PCE's anaerobic reaction products and suitable geochemical parameters for biological activity.
Date implemented:
Spring 2008- EZVI, Biostimulation, and ZVI
Summer 2009- Biostimulation and ZVI Injection
Final remediation design:
The Spring 2008 remedial event was implemented and designed by Innovative Environmental Technologies. 4 direct push injections were completed from 3 to 5' bgs and 10-12' bgs to treat soil hot spots in the vadose zone. Sufficient water was injected with the EZVI to artificially hydrate the vadose zone.
The groundwater was treated using 16 direct push injection points into the subsurface both inside and outside of the building. The injections were targeted from 18-34 feet bgs. The Spring 2008 remedial event distributed 4,000 pounds of ZVI, 425 pounds of calcium propionate, 125 pounds of an oxygen scavenger, vitamins B-2 and B-12, 1,800 pounds of HRC, and 440 gallons of EZVI.
The Summer 2009 injection event required a total of 5 direct push injections to treat an expanded area outside of the facility. The remedial design treated from 31-35 feet bgs and emplaced 1,350 pounds of ZVI, 125 pounds of calcium propionate, 50 pounds of an oxygen scavenger, 100 pounds of yeast, 100 pounds of nutrients, vitamins B-2 and B-12, and 450 pounds of HRC.
Other technologies used:
In-Situ: Emulsified Zero Valent Iron (EZVI)
Results to date:
Monitoring well MW-103 has reacted very favorably to the injection program implemented in 2009 with PCE concentrations decreasing by 99.9% from the March 2009 sampling event to the September 2009 sampling event. PCE concentrations decreased from 7,800 µg/L to 5.4 µg/L. TCE concentrations also decreased from 150 µg/L to below the laboratory detection limit. Cis-1,2-DCE concentrations increased dramatically from below the laboratory detection limit to 2,300 µg/L in September 2009. This increase indicates that reductive dechlorination is occurring at an elevated rate in MW-103. Field parameters also indicate favorable conditions present with a pH of 6.95 and a measured ORP of -117 mV.
Next Steps:
Two more groundwater sampling events scheduled for 12/09 and 3/10 that will sample all of the monitoring wells present on the site.
Cost to Design and Implement:
$166,205
|
In Situ Zero Valent Iron |
|
Why the technology was selected:
EZVI was chosen for the treatment of the shallow soil contaminated with PCE. EZVI was chosen to treat the hot spots present in the vadose zone under the facility.
Biostimulation and abiotic reductive dechlorination was chosen for the saturated zone due to the presence of PCE's anaerobic reaction products and suitable geochemical parameters for biological activity.
Date implemented:
Spring 2008- EZVI, Biostimulation, and ZVI
Summer 2009- Biostimulation and ZVI Injection
Final remediation design:
The Spring 2008 remedial event was implemented and designed by Innovative Environmental Technologies. 4 direct push injections were completed from 3 to 5' bgs and 10-12' bgs to treat soil hot spots in the vadose zone. Sufficient water was injected with the EZVI to artificially hydrate the vadose zone.
The groundwater was treated using 16 direct push injection points into the subsurface both inside and outside of the building. The injections were targeted from 18-34 feet bgs. The Spring 2008 remedial event distributed 4,000 pounds of ZVI, 425 pounds of calcium propionate, 125 pounds of an oxygen scavenger, vitamins B-2 and B-12, 1,800 pounds of HRC, and 440 gallons of EZVI.
The Summer 2009 injection event required a total of 5 direct push injections to treat an expanded area outside of the facility. The remedial design treated from 31-35 feet bgs and emplaced 1,350 pounds of ZVI, 125 pounds of calcium propionate, 50 pounds of an oxygen scavenger, 100 pounds of yeast, 100 pounds of nutrients, vitamins B-2 and B-12, and 450 pounds of HRC.
Other technologies used:
In-Situ: Emulsified Zero Valent Iron (EZVI)
Results to date:
Monitoring well MW-103 has reacted very favorably to the injection program implemented in 2009 with PCE concentrations decreasing by 99.9% from the March 2009 sampling event to the September 2009 sampling event. PCE concentrations decreased from 7,800 µg/L to 5.4 µg/L. TCE concentrations also decreased from 150 µg/L to below the laboratory detection limit. Cis-1,2-DCE concentrations increased dramatically from below the laboratory detection limit to 2,300 µg/L in September 2009. This increase indicates that reductive dechlorination is occurring at an elevated rate in MW-103. Field parameters also indicate favorable conditions present with a pH of 6.95 and a measured ORP of -117 mV.
Next Steps:
Two more groundwater sampling events scheduled for 12/09 and 3/10 that will sample all of the monitoring wells present on the site.
Cost to Design and Implement:
$166,205
|
Costs
Cost
for Assessment:
|
|
$116,012 |
Cost
for Operation and Maintenance:
|
|
|
Total
Costs for Cleanup:
|
|
$282,217.00 |
Contacts
Nancy Boisvert
Program Manager
TDEC-DoR
Drycleaner Response Program
401 Church St. Nashville TN
615-263-3876
Elizabeth Bishop
Innovative Environmental Technologies
6130 Kit Road, Pipersville, PA
www.iet-inc.net
888-721-8283
elizabethbishop@iet-inc.net
|
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