Drycleaner Site Profiles

Sable French Cleaners, Lake Worth, Florida

Description
Historical activity that resulted in contamination.

Sable French Cleaners is an active PCE drycleaning facility that has been in operation since 1975. The facility is located in a shopping center in a mixed retail commercial/residential setting. The contaminant source at the site was the soil under the facility floor slab in the vicinity of the drycleaning machine.

Contaminants
Contaminants present and the highest amount detected in both soil and groundwater.


Contaminant Media Concentration (ppb) Nondetect
cis-1,2-Dichloroethene groundwater 14.6 ppb
Tetrachloroethene (PCE) groundwater 9.7 ppb
Tetrachloroethene (PCE) soil 216 ppb
trans-1,2-Dichloroethene groundwater 0.9 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:   15ft bgs
Plume Size:   Plume Length: 40ft
Plume Width: 30ft
Plume Thickness: 15ft
Average Depth to Groundwater:   4.75ft

Lithology and Subsurface Geology

 
  Silty, fine-grained sand with shells
Depth: 0-14ft bgs
14ft thick
Conductivity: 62.9ft/day
Gradient: 0.0005ft/ft
 
  Silty, fine to medium-grained sand
Depth: 14-58ft bgs
44ft thick
 
  Fine to medium-grained sand
Depth: 58-73ft bgs
15ft thick

Pathways and DNAPL Presence

checkGroundwater
Sediments
checkSoil
DNAPL Present

Remediation Scenario

Cleanup Goals:
  Groundwater: PCE = 3.0 µg/L, cis 1,2-DCE = 70 µg/L, trans 1,2-DCE = 100 µg/L

Soil: 30 µg/Kg

Technologies

In Situ Monitored Natural Attenuation
 

Why the technology was selected:
Monitored natural attenuation was selected as the groundwater remedy, because contaminant concentrations in groundwater barely exceeded the MCL.

Date implemented:
December 19, 2001

Next Steps:
A Site Rehabilitation Completion Order will be issued for this site.

Cost to Design and Implement:
$84,400 for all technologies

In Situ Soil Vapor Extraction
 

Why the technology was selected:
SVE was selected, because soil samples collected beneath the facility floor slab failed Synthetic Precipitation Leaching Procedure testing. Contaminated soils were permeable (sand) and located beneath the facility floor of an operating drycleaning facility. SVE is an effective technology for removing VOCs from permeable unsaturated sediments.

Date implemented:
December 19, 2001

Final remediation design:
Two vertical 4-inch diameter Schedule 40 PVC vapor extraction wells were installed beneath the facility floor slab, screened from 1-3.5 ft bgs (0.020 slotted screen). Five passive vapor inlet wells were installed (2-inch diameter Schedule 40 PVC), screened 1-3.5 ft bgs with 0.020 slotted sceen. Three of the vapor inlet wells were installed beneath the facility floor slab, and one was installed outside the service door of the facility. Piping from the vapor extraction wells was routed to the ceiling of the facility and out the wall to the treatment compound. The remedial system is skid mounted. The system is powered by a 3 HP regenerative blower. Vapor treatment: two 200 lb. GAC vessels. The system has a 40-gallon moisture separtor. The design flow rate is 15 cfm, with design blower vacuums of 40-53 inches.

Results to date:
System was operated at 42-45 inches of vacuum. In March 2004, an additional vapor recovery well was installed adjacent to the drycleaning machine. A compliance inspection found that there were problems with the operation of the drycleaning separator water treatment unit. Operation of the SVE system was discontinued on October 13, 2004. Confirmatory soil sampling showed that contaminant concentrations in the soil were below cleanup target levels. An estimated 4.86 pounds of VOCs (PCE) was recovered by the system.

Next Steps:
A Site Rehabilitation Completion Order will be issued for this site.

Cost to Design and Implement:
$84,400 for all technologies

Ex Situ Carbon Adsorption
 

Date implemented:
December 19, 2001

Final remediation design:
Two vertical 4-inch diameter Schedule 40 PVC vapor extraction wells were installed beneath the facility floor slab, screened from 1-3.5 ft bgs (0.020 slotted screen). Five passive vapor inlet wells were installed (2-inch diameter Schedule 40 PVC), screened 1-3.5 ft bgs with 0.020 slotted sceen. Three of the vapor inlet wells were installed beneath the facility floor slab, and one was installed outside the service door of the facility. Piping from the vapor extraction wells was routed to the ceiling of the facility and out the wall to the treatment compound. The remedial system is skid mounted. The system is powered by a 3 HP regenerative blower. Vapor treatment: two 200 lb. GAC vessels. The system has a 40-gallon moisture separtor. The design flow rate is 15 cfm, with design blower vacuums of 40-53 inches.

Results to date:
System was operated at 42-45 inches of vacuum. In March 2004, an additional vapor recovery well was installed adjacent to the drycleaning machine. A compliance inspection found that there were problems with the operation of the drycleaning separator water treatment unit. Operation of the SVE system was discontinued on October 13, 2004. Confirmatory soil sampling showed that contaminant concentrations in the soil were below cleanup target levels. An estimated 4.86 pounds of VOCs (PCE) was recovered by the system.

Next Steps:
A Site Rehabilitation Completion Order will be issued for this site.

Cost to Design and Implement:
$84,400 for all technologies

Costs

Cost for Assessment:
  $67,800
Cost for Operation and Maintenance:
  O&M, including monitoring: $57,800 Site Restoration: $5,000
Total Costs for Cleanup:
  $215,000

Lessons Learned

1. The shallow water table, presence of silty sands in the unsaturated zone, and a suspected discharge from the drycleaning operation resulted in a longer system operation period than anticipated.

2. It is important to conduct periodic compliance inspections at active drycleaning facilities that are under remediation to ensure that the facilities maintain regulatory compliance.

Contacts

John Sykes, Project Manager
Bureau of Waste Cleanup (MS4520)
Florida Department of Environmental Protection
2600 Blair Stone Road
Tallahassee, Florida 32399-2400
Phone: (850) 245-8960
E-mail: John.Sykes@DEP.state.FL.us

Jay McGovern, PG
Tetra Tech EC, Inc.
759 South Federal Highway
Stuart, Florda 34994
Phone: (772) 781-3409

Site Specific References

Site Assessment Report - September 2000
Remedial Action Plan - May 2001
O&M/Monitoring Reports - 2002 - 2005