Drycleaner Site Profiles

Randolf's Cleaners & Alterations, Tallahassee, Florida

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

checkGroundwater
Sediments
checkSoil
checkDNAPL 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

Miranda Bartlett, Project Manger
Bureau of Waste Cleanup (MS4520)
Florida Department of Environmental Protection
2600 Blair Stone Road
Tallahassee, Florida 32399-2400

phone: (850) 245 8730
Miranda.Bartlett@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