Description
Historical activity that resulted
in contamination.
| Drylceaning Operations began at this facility in 1973. Petroleum solvent was utilized during the first twenty years of operations. In 1993, the facility switched to PCE. The drycleaning machine, service door, solvent storage and waste storage areas were identified as contaminant source areas.
The facility is located in a mixed retail commercial/residential setting. A municipal water supply well is located aproximately 160 feet northeast of the facility. The well produces from the Floridan aquifer at at a depth of 170 to 364 feet BGS and has been impacted by PCE. Remediation Status: In active remediation |
Contaminants
Contaminants present and the highest amount
detected in both soil and groundwater.
| Contaminant |
Media |
Concentration (ppb) |
Nondetect |
| cis-1,2-Dichloroethene |
groundwater |
|
|
| Tetrachloroethene (PCE) |
groundwater |
|
|
| Tetrachloroethene (PCE) |
soil |
|
|
| Trichloroethene (TCE) |
groundwater |
|
|
| Trichloroethene (TCE) |
soil |
|
|
| trans-1,2-Dichloroethene |
groundwater |
|
|
| Vinyl Chloride |
groundwater |
|
|
Site Hydrology
| Deepest Significant
Groundwater Contamination: |
|
156ft bgs |
| Plume Size: |
|
Plume Length: 350ft
Plume Width: 230ft
|
| Average Depth
to Groundwater: |
|
52.18ft |
Lithology and Subsurface Geology
|
|
silty to sandy clay interbedded with silt
Depth: 0-20ft bgs
20ft thick
Conductivity: 3ft/day
Gradient: 0.024ft/ft
|
|
|
silty clay to clay
Depth: 20-37ft bgs
17ft thick
|
|
|
silt, fine-grained sand with some clay
Depth: 37-53ft bgs
16ft thick
|
|
|
silty clay interbedded with silt
Depth: 53-80ft bgs
27ft thick
|
|
|
weathered limestone interbedded with sandy to plastic clay
Depth: 80-156ft bgs
76ft 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 µg/L; TCE = 3 µg/L; cis 1,2-DCE = 70 µg/L; vinyl chloride = 1 µg/L
Soil: PCE = 30 µg/Kg; TCE = 30 µg/Kg; TPH = 340,000 ug/Kg;
|
Remedy Level: |
|
Full Scale Remedy |
Technologies
In Situ Multi Phase Extraction |
|
Why the technology was selected:
Multi-phase extraction was chosen to recover contaminants through the drawdown of the water table in the relatively low-permeability sediments allowing for capture of VOCs by the SVE system. Hydraulic capture was augmented with two groundwater recovery wells. This is important given the proximity of the municipal supply well.
Date implemented:
August 21, 2003
Final remediation design:
MPE: Six, 5-inch diameter Schedule 40 PVC recovery wells screened 5-70 ft BGS, Plus two 5-inch recovery wells for hydraulic control, screened 30-70 ft BGS. Groundwater recovery is via 1/3 HP Grundfos electrical submersible pumps. Design pumping rate is a minimum 5 gpm at 90 ft TDH. Total groundwater flow rate was expected to be 16 gpm, maximum 20 gpm. Produced water is treated in a low-profile tray air stripper and then treated in two 90 lb. liquid phase GAC units. Treated water is discharged to the sanitary sewer.
Results to date:
After 65 months of operation, an estimated 626 pounds of chlorinated ethenes have been recovered. Approximately 90% of this contaminant mass was recovered from soil vapor. Approximately 6.7 million gallons of groundwater has been recovered and treated. Drawdown in the recovery wells aveaged 8.5 feet versus a design drawdown of 8 feet. Groundwater reovery rate now averages 2 gpm versus a design rate of 16 gpm. SVE total flow rate was approximately 560 scfm versus a design rate of 480 scfm. Vacuum in the recovery wells generally ranged from 9 to 10 inches of mercury versus a design rate of 14 inches.
One of the recovery wells produced very little groundwater and was taken out of service and was replaced with a recovery well installed just outside the backdoor of the drycleaning facility.
Contaminant concentrations in three recovery wells have decreased by two orders of magnitude, two orders of magnitude in three wells and are the same order of magnitude in three wells. The highest contaminant concentration detected in a groundwater sample collected during a January 2009 monitoring event was 670 ug/l PCE.
The SVE system operation rate has been 91% and the groundwater recovery system operation rate has been 79%. Downtime has been due to power interruptions, air stripper upsets and broken drive belts on the SVE system.
Hydraulic capture of the contaminant source area has been achieved.
Next Steps:
Currently evaluating whether it is necessary to operate the two groundwater recovery wells.
Cost to Design and Implement:
$298,500 for all technologies
|
In Situ Soil Vapor Extraction |
|
Why the technology was selected:
Multi-phase extraction was chosen to recover contaminants through the drawdown of the water table in the relatively low-permeability sediments allowing for capture of VOCs by the SVE system. Hydraulic capture was augmented with two groundwater recovery wells. This is important given the proximity of the municipal supply well.
Date implemented:
August 21, 2003
Final remediation design:
SVE: The SVE system consists of a 50 HP rotary lobe vacuum pump designed to operate at an extraction rate of approximately 480 SCFM at a vacuum of 16 inches of mercury. Extracted vapors are treated in two 2000-pound vapor phase GAC units.
Results to date:
After 65 months of operation, an estimated 626 pounds of chlorinated ethenes have been recovered. Approximately 90% of this contaminant mass was recovered from soil vapor. Approximately 6.7 million gallons of groundwater has been recovered and treated. Drawdown in the recovery wells aveaged 8.5 feet versus a design drawdown of 8 feet. Groundwater reovery rate now averages 2 gpm versus a design rate of 16 gpm. SVE total flow rate was approximately 560 scfm versus a design rate of 480 scfm. Vacuum in the recovery wells generally ranged from 9 to 10 inches of mercury versus a design rate of 14 inches.
One of the recovery wells produced very little groundwater and was taken out of service and was replaced with a recovery well installed just outside the backdoor of the drycleaning facility.
Contaminant concentrations in three recovery wells have decreased by two orders of magnitude, two orders of magnitude in three wells and are the same order of magnitude in three wells. The highest contaminant concentration detected in a groundwater sample collected during a January 2009 monitoring event was 670 ug/l PCE.
The SVE system operation rate has been 91% and the groundwater recovery system operation rate has been 79%. Downtime has been due to power interruptions, air stripper upsets and broken drive belts on the SVE system.
Hydraulic capture of the contaminant source area has been achieved.
Next Steps:
Currently evaluating whether it is necessary to operate the two groundwater recovery wells.
Cost to Design and Implement:
$298,500 for all technologies
|
Ex Situ Air Stripping |
|
Why the technology was selected:
Multi-phase extraction was chosen to recover contaminants through the drawdown of the water table in the relatively low-permeability sediments allowing for capture of VOCs by the SVE system. Hydraulic capture was augmented with two groundwater recovery wells. This is important given the proximity of the municipal supply well.
Date implemented:
August 21, 2003
Final remediation design:
MPE: Six, 5-inch diameter Schedule 40 PVC recovery wells screened 5-70 ft BGS, Plus two 5-inch recovery wells for hydraulic control, screened 30-70 ft BGS. Groundwater recovery is via 1/3 HP Grundfos electrical submersible pumps. Design pumping rate is a minimum 5 gpm at 90 ft TDH. Total groundwater flow rate was expected to be 16 gpm, maximum 20 gpm. Produced water is treated in a low-profile tray air stripper and then treated in two 90 lb. liquid phase GAC units. Treated water is discharged to the sanitary sewer.
SVE: The SVE system consists of a 50 HP rotary lobe vacuum pump designed to operate at an extraction rate of approximately 480 SCFM at a vacuum of 16 inches of mercury. Extracted vapors are treated in two 2000-pound vapor phase GAC units.
Results to date:
After 65 months of operation, an estimated 626 pounds of chlorinated ethenes have been recovered. Approximately 90% of this contaminant mass was recovered from soil vapor. Approximately 6.7 million gallons of groundwater has been recovered and treated. Drawdown in the recovery wells aveaged 8.5 feet versus a design drawdown of 8 feet. Groundwater reovery rate now averages 2 gpm versus a design rate of 16 gpm. SVE total flow rate was approximately 560 scfm versus a design rate of 480 scfm. Vacuum in the recovery wells generally ranged from 9 to 10 inches of mercury versus a design rate of 14 inches.
One of the recovery wells produced very little groundwater and was taken out of service and was replaced with a recovery well installed just outside the backdoor of the drycleaning facility.
Contaminant concentrations in three recovery wells have decreased by two orders of magnitude, two orders of magnitude in three wells and are the same order of magnitude in three wells. The highest contaminant concentration detected in a groundwater sample collected during a January 2009 monitoring event was 670 ug/l PCE.
The SVE system operation rate has been 91% and the groundwater recovery system operation rate has been 79%. Downtime has been due to power interruptions, air stripper upsets and broken drive belts on the SVE system.
Hydraulic capture of the contaminant source area has been achieved.
Next Steps:
Currently evaluating whether it is necessary to operate the two groundwater recovery wells.
Cost to Design and Implement:
$298,500 for all technologies
|
Ex Situ Carbon Adsorption |
|
Why the technology was selected:
Multi-phase extraction was chosen to recover contaminants through the drawdown of the water table in the relatively low-permeability sediments allowing for capture of VOCs by the SVE system. Hydraulic capture was augmented with two groundwater recovery wells. This is important given the proximity of the municipal supply well.
Date implemented:
August 21, 2003
Final remediation design:
MPE: Six, 5-inch diameter Schedule 40 PVC recovery wells screened 5-70 ft BGS, Plus two 5-inch recovery wells for hydraulic control, screened 30-70 ft BGS. Groundwater recovery is via 1/3 HP Grundfos electrical submersible pumps. Design pumping rate is a minimum 5 gpm at 90 ft TDH. Total groundwater flow rate was expected to be 16 gpm, maximum 20 gpm. Produced water is treated in a low-profile tray air stripper and then treated in two 90 lb. liquid phase GAC units. Treated water is discharged to the sanitary sewer.
SVE: The SVE system consists of a 50 HP rotary lobe vacuum pump designed to operate at an extraction rate of approximately 480 SCFM at a vacuum of 16 inches of mercury. Extracted vapors are treated in two 2000-pound vapor phase GAC units.
Results to date:
After 65 months of operation, an estimated 626 pounds of chlorinated ethenes have been recovered. Approximately 90% of this contaminant mass was recovered from soil vapor. Approximately 6.7 million gallons of groundwater has been recovered and treated. Drawdown in the recovery wells aveaged 8.5 feet versus a design drawdown of 8 feet. Groundwater reovery rate now averages 2 gpm versus a design rate of 16 gpm. SVE total flow rate was approximately 560 scfm versus a design rate of 480 scfm. Vacuum in the recovery wells generally ranged from 9 to 10 inches of mercury versus a design rate of 14 inches.
One of the recovery wells produced very little groundwater and was taken out of service and was replaced with a recovery well installed just outside the backdoor of the drycleaning facility.
Contaminant concentrations in three recovery wells have decreased by two orders of magnitude, two orders of magnitude in three wells and are the same order of magnitude in three wells. The highest contaminant concentration detected in a groundwater sample collected during a January 2009 monitoring event was 670 ug/l PCE.
The SVE system operation rate has been 91% and the groundwater recovery system operation rate has been 79%. Downtime has been due to power interruptions, air stripper upsets and broken drive belts on the SVE system.
Hydraulic capture of the contaminant source area has been achieved.
Next Steps:
Currently evaluating whether it is necessary to operate the two groundwater recovery wells.
Cost to Design and Implement:
$298,500 for all technologies
|
Ex Situ Pump and Treat |
|
Why the technology was selected:
Multi-phase extraction was chosen to recover contaminants through the drawdown of the water table in the relatively low-permeability sediments allowing for capture of VOCs by the SVE system. Hydraulic capture was augmented with two groundwater recovery wells. This is important given the proximity of the municipal supply well.
Date implemented:
August 21, 2003
Final remediation design:
MPE: Six, 5-inch diameter Schedule 40 PVC recovery wells screened 5-70 ft BGS, Plus two 5-inch recovery wells for hydraulic control, screened 30-70 ft BGS. Groundwater recovery is via 1/3 HP Grundfos electrical submersible pumps. Design pumping rate is a minimum 5 gpm at 90 ft TDH. Total groundwater flow rate was expected to be 16 gpm, maximum 20 gpm. Produced water is treated in a low-profile tray air stripper and then treated in two 90 lb. liquid phase GAC units. Treated water is discharged to the sanitary sewer.
Results to date:
After 65 months of operation, an estimated 626 pounds of chlorinated ethenes have been recovered. Approximately 90% of this contaminant mass was recovered from soil vapor. Approximately 6.7 million gallons of groundwater has been recovered and treated. Drawdown in the recovery wells aveaged 8.5 feet versus a design drawdown of 8 feet. Groundwater reovery rate now averages 2 gpm versus a design rate of 16 gpm. SVE total flow rate was approximately 560 scfm versus a design rate of 480 scfm. Vacuum in the recovery wells generally ranged from 9 to 10 inches of mercury versus a design rate of 14 inches.
One of the recovery wells produced very little groundwater and was taken out of service and was replaced with a recovery well installed just outside the backdoor of the drycleaning facility.
Contaminant concentrations in three recovery wells have decreased by two orders of magnitude, two orders of magnitude in three wells and are the same order of magnitude in three wells. The highest contaminant concentration detected in a groundwater sample collected during a January 2009 monitoring event was 670 ug/l PCE.
The SVE system operation rate has been 91% and the groundwater recovery system operation rate has been 79%. Downtime has been due to power interruptions, air stripper upsets and broken drive belts on the SVE system.
Hydraulic capture of the contaminant source area has been achieved.
Next Steps:
Currently evaluating whether it is necessary to operate the two groundwater recovery wells.
Cost to Design and Implement:
$298,500 for all technologies
|
Costs
Cost
for Assessment:
|
|
$147,800 |
Cost
for Operation and Maintenance:
|
|
$88,000 per year for O&M (includes groundwater monitoring, water disposal & utility payments) |
Total
Costs for Cleanup:
|
|
|
Lessons Learned
1. In low permeability sediments, considerable contaminant mass can be trapped in the unsaturated zone, capillary zone and the upper most portion of the saturated zone.
2. A seasonal rise in the water table at the site resulting in an order of magnitude increase in contaminant concentrations in monitor well groundwater samples indicates the presence of DNAPL in and near the capillary zone at the site.
3. Proximity of the public water supply well to the site and the low permeability sediments will mean a long operating period for the remedial system.
|
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
Kevin Warner, P.E., consultant
LFR Levine-Fricke, Inc.
3382 Capital Circle, N.E.
Tallahassee, Florida 32308-1568
phone: (850) 422-2555
Kevin.Warner@LFR.com
|
Site Specific References
Site Assessment Report - June 2001
MPE Pilot Test Report - May 2002
Remedial Action Plan - March 2003
Operation & Maintenance Reports: 2004 - 2009
|
|
