Drycleaner Site Profiles

Sunshine Cleaners, Tamarac, Florida

Description
Historical activity that resulted in contamination.

This is an active PCE drycleaning facility that has been in operation since 1978. The facility is located in a shopping center in a retail commercial/residential setting.

Remediation Status: Site closed


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


Contaminant Media Concentration (ppb) Nondetect
cis-1,2-Dichloroethene groundwater 216 ppb
1,1-Dichloroethene groundwater 4.1 ppb
Tetrachloroethene (PCE) groundwater 627 ppb
Tetrachloroethene (PCE) soil 170 ppb
Trichloroethene (TCE) groundwater 527 ppb
trans-1,2-Dichloroethene groundwater 10.5 ppb
Vinyl Chloride groundwater 7.9 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:   55ft bgs
Plume Size:   Plume Length: 480ft
Plume Width: 120ft
Plume Thickness: 55ft
Average Depth to Groundwater:   8ft

Lithology and Subsurface Geology

 
  silty, fine-grained sand
Depth: 0-30ft bgs
30ft thick
Conductivity: 128ft/day
Gradient: 0.0008ft/ft
 
  fine to medium-grained sand, some limestone gravel and shells
Depth: 30-65ft bgs
35ft 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):
  Soil Vapor Extraction

Remediation Scenario

Cleanup Goals:
  Groundwater: PCE = 3.0 µg/L, TCE = 3.0 µg/L, cis 1,2-DCE = 70 µg/L, trans 1,2-DCE = 100 µg/L, 1,1-DCE = 7.0 µg/L, vinyl chloride = 1.0 µg/L
Soil: PCE = 30 µg/L (leachability)

Technologies

In Situ Monitored Natural Attenuation
 

Why the technology was selected:
Monitored natural attenuation was selected as the groundwater remedy because of the relatively low contaminant concentrations in groundwater and the presence of degradation products, demonstrating that reductive dechlorination was occurring in groundwater at the site.

Results to date:
The SVE system was operated until June 28, 2002. The system operated at an average of 33.2 scfm with a vacuum of from 13.7-15.9 inches w.c. in the recovery wells. The system recovered an estimated 6.2 lbs. of VOCs. Groundwater monitoring continued after system shut down and the final groundwater monitoring event occurred in August of 2005.

Next Steps:
The site has reached No Further Action criteria and will be closed.

In Situ Soil Vapor Extraction
 

Why the technology was selected:
Soil Vapor Extraction was selected because is has proved to be an effective technology for removing VOCs from permeable unsaturated soils.

Date implemented:
January 31, 2002

Final remediation design:
Two 2-inch diameter Schedule 40 PVC vapor extraction wells were installed beneath the floor slab of the drycleaning facility to a depth of 7 ft and screened from 2-7 ft. Piping was run vertically from the vapor extraction wells to the ceiling of the facility and then out the rear wall of the facility to a skid mounted SVE system. A 2-HP positive displacement blower was utilized. A 170-lb. granular activated carbon canister was used for vapor treatment. Design flow rate was 20 scfm with 14 inches of vacuum in each vapor recovery well.

Results to date:
The SVE system was operated until June 28, 2002. The system operated at an average of 33.2 scfm with a vacuum of from 13.7-15.9 inches w.c. in the recovery wells. The system recovered an estimated 6.2 lbs. of VOCs. Groundwater monitoring continued after system shut down and the final groundwater monitoring event occurred in August of 2005.

Next Steps:
The site has reached No Further Action criteria and will be closed.

Cost to Design and Implement:
Design: $15,800 Construction & Startup: $82,200

Costs

Cost for Assessment:
  $99,900
Cost for Operation and Maintenance:
  O&M: $31,900 Monitoring: $31,800 Site Restoration: $5,000
Total Costs for Cleanup:
  $266,600

Lessons Learned

1. Closure of sites with low level, shallow groundwater contamination can be achieved by remediating the unsaturated zone soil source.
2. Left untreated, contaminants present in the unsaturated zone beneath a building will continue to source groundwater contamination when the water table contacts the unsaturated zone source during seasonal rises.
3. Installation of vapor reovery wells beneth the floor slab and as close to the source as possible (very often in and near the location or former location of the drycleaning machines) is an effective remedial technique.

Contacts

Aaron Cohen, Project Manager
Bureau of Waste Cleanup (MS4520)
Florida Department of Environmetal Protection
2600 Blair Stone Road
Tallahassee, Florida 32399-2400
Phone: (850)245-8962
e-mail: aaron.cohen@dep.state.fl.us

Bruce Wilson, PG, Consultant
Ecology & Environment
1950 Commonwealth Lane
Tallahassee, Florida 32303
Phone: (850) 574-1179

Site Specific References

Site Assessment Report - February 2000
Remedial Action Plan - June 2001
Operation & Maintenance Reports & Monitoring Reports