Description
Historical activity that resulted
in contamination.
| Drycleaning operations began at this facility in the early 1960s. PCE was used as the drycleaning solvent until operations were suspended in January of 1996. The facility resumed operations in October of 1997 utilizing Exxon DF-2000 (high-flash petroleum solvent).
Chlorinated solvents were detected in wastewater and sludge samples collected in 1995 from the septic tank which serves the facility and the tank was pumped out and cleaned. In October of 1997, prior to admission to the Florida Drycleaning Solvent Cleanup Program, a pump and treat system was installed and operated at the site and recovered a reported 562,760 gallons of water. Water was treated by a GAC unit and the treated water was discharged to a stormwater drain (soakage pit) at the site.
The facility is located in a mixed retail commercial/residential setting. The drycleaning facility is located approximately half a mile south of the nearest wells of a large water supply field. The well field has been impacted by chlorinated solvents.
Drycleaning operations ceased at the facility in 2005. Remediation Status: In groundwater monitoring |
Contaminants
Contaminants present and the highest amount
detected in both soil and groundwater.
| Contaminant |
Media |
Concentration (ppb) |
Nondetect |
| cis-1,2-Dichloroethene |
groundwater |
1,120 ppb |
|
| cis-1,2-Dichloroethene |
soil |
170 ppb |
|
| Tetrachloroethene (PCE) |
groundwater |
60,300 ppb |
|
| Tetrachloroethene (PCE) |
soil |
7,800,000 ppb |
|
| Trichloroethene (TCE) |
groundwater |
1,890 ppb |
|
| Trichloroethene (TCE) |
soil |
5,900 ppb |
|
| trans-1,2-Dichloroethene |
groundwater |
16 ppb |
|
| Vinyl Chloride |
groundwater |
278 ppb |
|
Site Hydrology
| Deepest Significant
Groundwater Contamination: |
|
100ft bgs |
| Plume Size: |
|
Plume Length: 2,400ft
Plume Width: 150ft
Plume Thickness: 100ft |
| Average Depth
to Groundwater: |
|
9ft |
Lithology and Subsurface Geology
|
|
fine grained sand with limestone stringers
Depth: 0-12ft bgs
12ft thick
Conductivity: 50ft/day
Gradient: 0.0014ft/ft
|
|
|
fine-grained sand
Depth: 12-32ft bgs
20ft thick
|
|
|
fine-grained sand with limestone stingers
Depth: 32-41ft bgs
9ft thick
|
|
|
limestone with fine-grained sand interbeds
Depth: 41-80ft bgs
39ft 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? |
|
Yes |
Type of Vapor Mitigation System(s): |
|
Soil Vapor Extraction
|
Remediation Scenario
Cleanup
Goals: |
|
Groundwater; PCE = 3 ug/l, TCE = 3 ug/l, Cis 1,2-DCe = 70 ug/l, Trans 1,2-DCe = 100 ug/l, Vinyl Chloride = 1 ug/l
Soil: PCE = 30 ug/kg, TCE = 30 ug/kg
|
Remedy Level: |
|
Full Scale Remedy |
Technologies
In Situ Bioremediation |
|
Why the technology was selected:
Bioremediation was chosen to polish low levels of VOCs in the groundwater in the contaminant source area because reductive dechlorination was actively occurring in groundwater (daughter products present, dissolved oxygen concentrations < 0.5 mg/l, Redox ~ -200 millivolts, pH 6.82 to 7.56 standard units.
Date implemented:
First potassium lactate injection event: February 9-10, 2007.
Final remediation design:
Bioremediation: Two 2-inch PVC injection wells installed outside sevice door of drycleaning facility. The wells are screened 10-20 ft BLS.
In the first injection event, a total of 17 gallons of potassium lactate was mixed with 9,600 gallons of water and injected in each well (total of 19,234 gallons of K-lacate solution for each injection event).
Results to date:
Approximately 270 tons of contaminated soils/sediments removed from two stormwater soakage pit (French drains); 1,100 gallons of wastewater removed from septic tank; Two 55 gallon drums of contaminated sediments removed from stormwater catchment basins and one 55-gallon drum of contaminated water removed from catchment basins.
Contaminant concentrations in groundwater dropped three orders of magnitude after excavation/removal action. PCE concentrations in source area monitor wells were 10 - 15 ug/l (June 2007).
Soil vapor extraction system operated from May 19, 2004 until September 2005. An Estimated 0.6 lbs. of VOCs were recovered. Confirmation soil sampling showed that cleanup target levels have been met.
A total of six (6)potassium lactate injection events were conducted (in February, April, July and November of 2007 and in March and June of 2008). A total of 17 gallons of 60% potassium lactate solution mixed with 9,600 gallons of water was utilized for each of the two injection wells during each injection event.
Next Steps:
The site is now in groundwater monitoring. A groundwater monitoring event conducted on July 16, 2008 found the highest contaminant concentration in a groundwater sample was 1.6 ug/l PCE. There are plans to collect soil gas samples from beneath the facility floor slab to determine if the SVE system effectively remediated the unsaturated zone under the building.
Cost to Design and Implement:
All technologies: Design: $43,200
Implementation: $199,900
|
In Situ Soil Vapor Extraction |
|
Why the technology was selected:
SVE was chosen because it is an effective technology for removal of VOCs from permeable soils (sand in this case).
Date implemented:
SVE: May 19, 2004
Final remediation design:
The SVE system consists of two horizontal vapor extraction wells constructed of 4-inch diameter PVC and installed four been below ground near the back door of the drycleaning facility. The system is powered by a 15 HP regenerative Rotron blower. Vapors are treated via two 140-lb. GAC units. The system was designed to operate with a flow of 285 scfm and 24 inches water gauge of vacuum at the wellheads with a design radius of influence of 38 feet.
Results to date:
Approximately 270 tons of contaminated soils/sediments removed from two stormwater soakage pit (French drains); 1,100 gallons of wastewater removed from septic tank; Two 55 gallon drums of contaminated sediments removed from stormwater catchment basins and one 55-gallon drum of contaminated water removed from catchment basins.
Contaminant concentrations in groundwater dropped three orders of magnitude after excavation/removal action. PCE concentrations in source area monitor wells were 10 - 15 ug/l (June 2007).
Soil vapor extraction system operated from May 19, 2004 until September 2005. An Estimated 0.6 lbs. of VOCs were recovered. Confirmation soil sampling showed that cleanup target levels have been met.
A total of six (6)potassium lactate injection events were conducted (in February, April, July and November of 2007 and in March and June of 2008). A total of 17 gallons of 60% potassium lactate solution mixed with 9,600 gallons of water was utilized for each of the two injection wells during each injection event.
Next Steps:
The site is now in groundwater monitoring. A groundwater monitoring event conducted on July 16, 2008 found the highest contaminant concentration in a groundwater sample was 1.6 ug/l PCE. There are plans to collect soil gas samples from beneath the facility floor slab to determine if the SVE system effectively remediated the unsaturated zone under the building.
Cost to Design and Implement:
All technologies: Design: $43,200
Implementation: $199,900
|
Ex Situ Carbon Adsorption |
|
Date implemented:
SVE: May 19, 2004
Final remediation design:
The SVE system consists of two horizontal vapor extraction wells constructed of 4-inch diameter PVC and installed four been below ground near the back door of the drycleaning facility. The system is powered by a 15 HP regenerative Rotron blower. Vapors are treated via two 140-lb. GAC units. The system was designed to operate with a flow of 285 scfm and 24 inches water gauge of vacuum at the wellheads with a design radius of influence of 38 feet.
Results to date:
Approximately 270 tons of contaminated soils/sediments removed from two stormwater soakage pit (French drains); 1,100 gallons of wastewater removed from septic tank; Two 55 gallon drums of contaminated sediments removed from stormwater catchment basins and one 55-gallon drum of contaminated water removed from catchment basins.
Contaminant concentrations in groundwater dropped three orders of magnitude after excavation/removal action. PCE concentrations in source area monitor wells were 10 - 15 ug/l (June 2007).
Soil vapor extraction system operated from May 19, 2004 until September 2005. An Estimated 0.6 lbs. of VOCs were recovered. Confirmation soil sampling showed that cleanup target levels have been met.
A total of six (6)potassium lactate injection events were conducted (in February, April, July and November of 2007 and in March and June of 2008). A total of 17 gallons of 60% potassium lactate solution mixed with 9,600 gallons of water was utilized for each of the two injection wells during each injection event.
Next Steps:
The site is now in groundwater monitoring. A groundwater monitoring event conducted on July 16, 2008 found the highest contaminant concentration in a groundwater sample was 1.6 ug/l PCE. There are plans to collect soil gas samples from beneath the facility floor slab to determine if the SVE system effectively remediated the unsaturated zone under the building.
Cost to Design and Implement:
All technologies: Design: $43,200
Implementation: $199,900
|
Ex Situ Soil Removal |
|
Why the technology was selected:
Excavation/Removal was selected because high concentrations of contaminants were present in soils and sediments,(7,800,000 ug/kg PCE), stormwater catch basin/soakage pit sediments (125,000 ug/kg PCE) and septic tank sludges (98,000 ug/kg), and those soils/sediments were accessible.
Date implemented:
Excavation/Removal: May/June 2001
Results to date:
Approximately 270 tons of contaminated soils/sediments removed from two stormwater soakage pit (French drains); 1,100 gallons of wastewater removed from septic tank; Two 55 gallon drums of contaminated sediments removed from stormwater catchment basins and one 55-gallon drum of contaminated water removed from catchment basins.
Contaminant concentrations in groundwater dropped three orders of magnitude after excavation/removal action. PCE concentrations in source area monitor wells were 10 - 15 ug/l (June 2007).
Soil vapor extraction system operated from May 19, 2004 until September 2005. An Estimated 0.6 lbs. of VOCs were recovered. Confirmation soil sampling showed that cleanup target levels have been met.
A total of six (6)potassium lactate injection events were conducted (in February, April, July and November of 2007 and in March and June of 2008). A total of 17 gallons of 60% potassium lactate solution mixed with 9,600 gallons of water was utilized for each of the two injection wells during each injection event.
Next Steps:
The site is now in groundwater monitoring. A groundwater monitoring event conducted on July 16, 2008 found the highest contaminant concentration in a groundwater sample was 1.6 ug/l PCE. There are plans to collect soil gas samples from beneath the facility floor slab to determine if the SVE system effectively remediated the unsaturated zone under the building.
Cost to Design and Implement:
All technologies: Design: $43,200
Implementation: $199,900
|
Costs
Cost
for Assessment:
|
|
$247,600 |
Cost
for Operation and Maintenance:
|
|
|
Total
Costs for Cleanup:
|
|
|
Lessons Learned
|
1. In terms of contaminant mass removed and resulting drop in contaminant concentrations in groundwater, the excavation/removal action has by far been the most effective remedial action taken at the site.
|
Contacts
Aaron Cohen
Florida Dept. of Environmental Protection
Bureau of Waste Cleanup, MS 4500
2600 Blair Stone Road
Tallahassee, Florida 32399
850-245-8974
Aaron.Cohen@dep.state.fl.us
Guy Frearson, Consultant
Metcalf & Eddy AECOM
13450 West Sunrise Boulevard
Sunrise, Florida 33323
Phone: (9540 745-7211
Guy.Frearson@M-E.aecom.com
|
Site Specific References
Site Assessment Report: May 2001
Remedial Action Plan: November 2002
Soil Vapor Extraction System Startup Report: June 2004
Operation & Maintenance/Monitoring reports: 2004-2008
|
|
