Supreme USA Cleaners, Tamarac, Florida

State Coalition for Remediation of Drycleaners Site Profiles

Description
Historical activity that resulted in contamination.

Drycleaning using PCE was performed at this facility from June of 1995 until November of 1999. The site is located in a shopping center in a mixed retail commercial/residential setting. The contaminant source area was the area outside the service door (behind the facility) where a concrete patch had been placed over an asphalt area.

Remediation Status: Site closed

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

Contaminant	Media	Concentration (ppb)
cis-1,2-Dichloroethene	groundwater	641 ppb
cis-1,2-Dichloroethene	soil	26 ppb
1,1-Dichloroethene	groundwater	4.8 ppb
Tetrachloroethene (PCE)	groundwater	585 ppb
Tetrachloroethene (PCE)	soil	730 ppb
Trichloroethene (TCE)	groundwater	245 ppb
Trichloroethene (TCE)	soil	76 ppb
trans-1,2-Dichloroethene	groundwater	8.6 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:		50ft bgs
Plume Size:		Plume Length: 115ft Plume Width: 65ft Plume Thickness: 45ft
Average Depth to Groundwater:		4.96ft

Lithology and Subsurface Geology

		soft, sandy limestone with limestone cobbles Depth: 0-3.5ft bgs 3.5ft thick Conductivity: 50ft/day Gradient: 0.008ft/ft
		peat Depth: 3.5-4ft bgs 0.5ft thick
		vuggy, hard limestone "caprock" with vugs and cavities filled with silt & very fine to fine-grained organic sand Depth: 4-7ft bgs 3ft thick
		sandy, fossiliferous limestone Depth: 7-14.5ft bgs 7.5ft thick
		fine-grained sand Depth: 14.5-28ft bgs 13.5ft thick
		sandy limestone Depth: 28-49ft bgs 21ft thick
		very fine to fine-grained sand Depth: 49-52ft bgs 3ft thick
		sandy fossiliferous limestone Depth: 52-101ft bgs 49ft thick

Pathways and DNAPL Presence

Groundwater

Sediments

Soil

DNAPL Present

Remediation Scenario

Cleanup Goals:

Groundwater: PCE = 3 ug/l, TCE = 3 ug/l, cis 1,2-DCE = 70 ug/l, trans 1,2-DCE = 100 ug/l, 1,1-DCE = 7 ug/l

Soil: PCE = 30 ug/kg. TCE = 30 ug/kg, cis 1,2-DCE = 400 ug/kg, trans 1,2-DCE = 700 ug/kg

Technologies

In Situ Monitored Natural Attenuation

Why the technology was selected:
Monitored natural attenuation was selected as the groundwater remedy after the sharp decline in contaminant concentrations in groundwater following the excavation.

Next Steps:
A Site Rehabilitation Completion Order was issued for the site on

Cost to Design and Implement:
$35,800 for all technologies

Ex Situ Soil Removal

Why the technology was selected:
Removal was selected because of easy access (contaminated soil located under a paved alley) and a shallow water table.

Date implemented:
September 12 - 20, 2000

Final remediation design:
The plan was to excavate an area of 10 ft x 10 feet to the water table (approximatley 4 feet BLS) in the service alley behind the service door to the former drycleaning facility.

Results to date:
The interim remedial measure (soil excavation) was performed before the contaminaiton assessment was completed. A hard limestone (caprock) was encountered below the peat which precluded deeper excavation. The caprock surface was undulating which permitted deeper excavation in some areas. The excavation area was expanded twice based on confirmatory soil sampling. The final area of excavation was approximatley 20 feet x 25 feet to an average depth of 4 feet. When the excavation was expanded the first two roll-offs of excavated soil had to be removed before proceeding with additional excavation because there was not enough room to state additional roll-offs. Approximately 74 yards of contaminated soil was excavated (approximately 96.7 tons), removed from the site and disposed of as non-hazardous. The excavation was backfilled and repaved. SPLP leachate extracted from confirmatory soil samples showed that remaining contaminant concentrations in soils were not at levels that would continue to act as a source for groundwater contamination. Contaminant concentrations in groundwater showed significant decreases after the excavation and groundwater monitoring was completed in September of 2003, three years after the excavation.

Next Steps:
A Site Rehabilitation Completion Order was issued for the site on

Cost to Design and Implement:
$35,800 for all technologies

Costs

Cost for Assessment:		$126,800
Cost for Operation and Maintenance:		Monitoring: $9,800 Site Restoration: $4,700
Total Costs for Cleanup:		$177,000

Lessons Learned

1. Use of an onsite mobile laboratory to analyze soil samples during the excavation saved time and money.

2. The bulk of the PCE mass at the site was sorbed onto the peat layer which occured at or near the water table. This zone was sourceing the groundwater contamination and once it was removed, contaminant concentrations declined rapidly.

3. in hindsight, conducting a few additional shallow borings in the projected excavation area to determine lateral variations in lithology would have been useful to anticpate excavation problems.

4. Conducting the excavation before the site assessment was completed resulted in a timely closure for the site.

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

Gregg Roberts, PG
Shaw Environmental, Inc.
725 U.S. Highway 301 South
Tampa, Florida 33619-3439
Phone (3180 612-3687
gregg.roberts@shawgrp.com

Site Specific References

Site Assessment Report - May 2001

Interim Source Removal Report - December 2000

Groundwater Monitoring Reports 2002 - 2003

Top of Page

U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

State Coalition for Remediation of Drycleaners Site Profiles