Drycleaner Site Profiles

Ace Quality Cleaners, Orlando, Florida

Description
Historical activity that resulted in contamination.

This is an active PCE drycleaning facility that has been in operation since 1967. It is located in a strip shopping center in a mixed retail commercial/residential setting. The contaminant source area is the soils beneath the facility floor slab in the vicinity of the drycleaning machine.

Remediation Status: Site closed


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


Contaminant Media Concentration (ppb) Nondetect
1,1-Dichloroethene groundwater 10 ppb
Tetrachloroethene (PCE) groundwater 10 ppb
Tetrachloroethene (PCE) groundwater 10 ppb
groundwater 10 ppb
groundwater 10 ppb
soil 67 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:   43ft bgs
Plume Size:   Plume Length: 65ft
Plume Width: 40ft
Plume Thickness: 30ft
Average Depth to Groundwater:   15ft

Lithology and Subsurface Geology

 
  fine-grained sand
Depth: 0-43ft bgs
43ft thick
Conductivity: 1.48ft/day
Gradient: 0.0098ft/ft
 
  dense clay
Depth: 43-48ft bgs
5ft thick
 
  clayey, fine-grained sand with limestone lenses
Depth: 48-94ft bgs
46ft thick
 
  sandy limestone
Depth: 94-100ft bgs
6ft thick

Pathways and DNAPL Presence

checkGroundwater
Sediments
checkSoil
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):
  Passive Vapor Barrier
Sub-slab Depressurization
Sub-slab Pressurization
Passive Venting
HVAC controls/modifications
Soil Vapor Extraction

Remediation Scenario

Cleanup Goals:
  Groundwater: PCE = 3.0 µg/l; 1,1-DCE = 7.0 µg/L

Soil: PCE = 30 µg/kg
Remedy Level:
  Full Scale Remedy

Technologies

in Situ Monitored Natural Attenuation
 

Why the technology was selected:
Due to low contaminant levels in soil and groundwater, monitored natural attenutation was initially chosen as the remedy at the site. After two and one-half years of monitoring and no decline in contaminant concentrations in groundwater, the decision was made to conduct an active soil gas survey to evaluate the mass of VOCs present in the unsaturated zone in the contaminant source area. Four vapor monitoring points were installed (1.25-inch diameter PVC, screened 5-10 ft BLS). Two of the vapor monitoring points were installed beneath the facility floor slab and two were installed outside the facility (one outside service door and the other one on the side of the faciliy). A portable regenerative blower was run at 12-72 cfm to recovery vapor samples from each vapor monitoring point for a period of one hour for each sampling point. Soil gas samples were monitored with a PID and at the end of each sampling period, a soil gas sample was collected for fixed laboratory analysis. Fixed laboratory analysis of these samples found PCE in concentrations ranging from 8.2 to 25 mg/cubic meter. The decision was made to install a SVE system at the site.

in Situ Soil Vapor Extraction
 

Why the technology was selected:
Due to low contaminant levels in soil and groundwater, monitored natural attenutation was initially chosen as the remedy at the site. After two and one-half years of monitoring and no decline in contaminant concentrations in groundwater, the decision was made to conduct an active soil gas survey to evaluate the mass of VOCs present in the unsaturated zone in the contaminant source area. Four vapor monitoring points were installed (1.25-inch diameter PVC, screened 5-10 ft BLS). Two of the vapor monitoring points were installed beneath the facility floor slab and two were installed outside the facility (one outside service door and the other one on the side of the faciliy). A portable regenerative blower was run at 12-72 cfm to recovery vapor samples from each vapor monitoring point for a period of one hour for each sampling point. Soil gas samples were monitored with a PID and at the end of each sampling period, a soil gas sample was collected for fixed laboratory analysis. Fixed laboratory analysis of these samples found PCE in concentrations ranging from 8.2 to 25 mg/cubic meter. The decision was made to install a SVE system at the site.

in Situ Monitored Natural Attenuation
 

Why the technology was selected:
Due to low contaminant levels in soil and groundwater, monitored natural attenutation was initially chosen as the remedy at the site. After two and one-half years of monitoring and no decline in contaminant concentrations in groundwater, the decision was made to conduct an active soil gas survey to evaluate the mass of VOCs present in the unsaturated zone in the contaminant source area. Four vapor monitoring points were installed (1.25-inch diameter PVC, screened 5-10 ft BLS). Two of the vapor monitoring points were installed beneath the facility floor slab and two were installed outside the facility (one outside service door and the other one on the side of the faciliy). A portable regenerative blower was run at 12-72 cfm to recovery vapor samples from each vapor monitoring point for a period of one hour for each sampling point. Soil gas samples were monitored with a PID and at the end of each sampling period, a soil gas sample was collected for fixed laboratory analysis. Fixed laboratory analysis of these samples found PCE in concentrations ranging from 8.2 to 25 mg/cubic meter. The decision was made to install a SVE system at the site.

in Situ Monitored Natural Attenuation
 

Why the technology was selected:
Due to low contaminant levels in soil and groundwater, monitored natural attenutation was initially chosen as the remedy at the site. After two and one-half years of monitoring and no decline in contaminant concentrations in groundwater, the decision was made to conduct an active soil gas survey to evaluate the mass of VOCs present in the unsaturated zone in the contaminant source area. Four vapor monitoring points were installed (1.25-inch diameter PVC, screened 5-10 ft BLS). Two of the vapor monitoring points were installed beneath the facility floor slab and two were installed outside the facility (one outside service door and the other one on the side of the faciliy). A portable regenerative blower was run at 12-72 cfm to recovery vapor samples from each vapor monitoring point for a period of one hour for each sampling point. Soil gas samples were monitored with a PID and at the end of each sampling period, a soil gas sample was collected for fixed laboratory analysis. Fixed laboratory analysis of these samples found PCE in concentrations ranging from 8.2 to 25 mg/cubic meter. The decision was made to install a SVE system at the site.

in Situ Soil Vapor Extraction
 

Why the technology was selected:
Soil vapor extraction was chosen to address contamination in the unsaturated zone because it is an effective technology for removing VOCs in permeable unsaturated sediments.

Date implemented:
SVE system: September 24, 2004

Date completed:
July 1, 2005 (~ 8 months of operation)

Final remediation design:
One two-inch diameter Schedule 40 PVC vapor recovery well installed beneath the facility floor slab (screened 2-12 ft BLS). System powered by 1.5 HP Ametek Rotron regenerative blower. Off gas treated by 200 lb. G.A.C. unit.

System run at 43 scfm with 28 inches applied vacuum.

Results to date:
The SVE system was shut down on July 1, 2005. Groundwater monitoring continued for another year. Groundwater cleanup target levels were achieved in early 2006.

Next Steps:
The site has achieved No Further Action status. A Site Rehabilitation Completion Order was issued for the site on December 14, 2006.

Cost to Design and Implement:
$65,800 (includes active soil gas survey)

Costs

Cost for Assessment:
  $67,500
Cost for Operation and Maintenance:
  $54,400
Total Costs for Cleanup:
  $200,400 (includes $12,700 for closure reporting & site restoration)

Lessons Learned

1. An active soil gas survey provided a more representative picture of VOC mass distribution in the contaminant source area than conventional soil sampling and analysis.

2. At most PCE drycleaning facilities there will be enough PCE in the unsaturated zone under the facility floor slab to continue to cause MCL exceedances in shallow groundwater if not addressed.

Contacts

Walsta Jean Baptiste, Project Manager
Bureau of Waste Cleanup (MS4520)
Florida Department of Environmental Protection
2600 Blair Stone Road
Tallahassee, Florida 32399-2400
Phone: (850) 245-8973
E-mail: Walsta.JeanBaptiste@DEP.state.fl.us

Mike Lodato, PG
GeoSyntec Consultants
14055 Riveredge Drive, Suite 300
Tampa, Florida 33637
Phone: (813) 558-9829
E-mail: mlodato@geosyntec.com

Site Specific References

Contamination Assessment Report - 2001
Limited Remedial Action Plan - 2004
Construction Report - 2004
Operation & Maintenance Reports
Groundwater Monitoring Reports