Drycleaner Site Profiles

The Dry Cleaner, Altamonte Springs, Florida

Description
Historical activity that resulted in contamination.

This an inactive PCE drycleaning facility that operated from 1990 to 1998. It is located in a strip mall adjacent to a residential neighborhood. Most of the residences obtain drinking water from private wells completed in the Floridan aquifer at depths as shallow as 95 feet bgs. The nearest municipal water supply well is located within a half mile of the site. The contaminant source area was located in the soil beneath the building 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
Tetrachloroethene (PCE) groundwater 7.2 ppb
Tetrachloroethene (PCE) soil 91,700 ppb
Trichloroethene (TCE) groundwater 1 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:   80ft bgs
Plume Size:   Plume Length: 100ft
Plume Width: 80ft
Average Depth to Groundwater:   48ft

Lithology and Subsurface Geology

 
  Slightly silty, fine to medium-grained quartz sands with lenses of clayey sand
Depth: 0-38ft bgs
38ft thick
Conductivity: 2.3ft/day
Gradient: 0.002ft/ft
 
  Slightly sandy, phosphatic clay interbedded with white, fossilliferous, sandy limestone
Depth: 38-61ft bgs
23ft thick
Conductivity: 0.2ft/day
 
  Sandy clay and clayey sand
Depth: 61-95ft bgs
34ft thick
Conductivity: 7.9ft/day
 
  Fossiliferous limestone
Depth: 95-130ft 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:
  Maximum Contaminant Levels (Groundwater - MCLs) PCE = 3.0 mg/L, TCE = 3.0 mg/L.
Soils - leachability level - PCE = 30 mg/kg

Technologies

In Situ Soil Vapor Extraction
 

Why the technology was selected:
The predominant portion of the contaminant mass was located in the unsaturated zone at the site in sandy soils. The depth to water at the site was relatively deep.

Date implemented:
March 1999

Final remediation design:
The SVE system operated for approximately six months with one extraction well using the following design: Depth: 40 ft bgs Screened interval: 10-40 ft bgs Motor size: 3 hp Capacity: 147 scfm (at design vacuum of 66 in. w.c.) Ultimate flow rate: 160 scfm (at zero vacuum); 50 cfm (at 190 in. w.c.) Emissions treatment: Two 200 lb. GAC canisters System performance was monitored by soil vapor samples collected weekly for the first month, monthly for the next two months, and quarterly thereafter. Site rehabilitation progress was monitored by groundwater samples collected at system start-up and quarterly thereafter.

Results to date:
Confirmatory soil sampling indicates that contaminant concentrations were below FDEP SCTLs. Additionally, with the exception of 10 mg/kg of PCE at a depth of one foot at one soil boring, all VOC concentrations were below laboratory detection limits. At the time of final monthly sampling the system had removed a total mass of 3.77 pounds of VOCs from the subsurface soils. PCE concentrations in groundwater samples decreased to below CTLs. In addition, the most recent laboratory analyses indicated that contaminant concentrations were all below CTLs and laboratory detection limits for all monitor wells. Remediation is complete. Criteria for No Further Action have been met. The Site Rehabilitation Completion Order has been filed and the site closed.

Cost to Design and Implement:
$ 77,779.22 (SVE system was put into a trailer for use at other drycleaning sites.)

Costs

Cost for Assessment:
  $105,875.03
Cost for Operation and Maintenance:
  $44,544.02
Total Costs for Cleanup:
  $228,198.27

Lessons Learned

1. SVE can remediate the vadose zone in a relatively short time period.
2. Project was successful due to comprehensive data collection during site assessment work and application of an appropriate remedial technology.

Contacts

Karen Milicic, Project Manager
Florida Department of Environmental Protection
(850) 245-8931
Karen Milicic@dep.state.fl.us

Contractor:
Kelly Bishop
International Technology Corporation
(813) 626-2336
kbishop@theitgroup.com

Site Specific References

1. IT Contamination Assessment Report-7/97
2. IT Remedial Action Plan-11/98
3. IT Site Rehabilitation Completion Report-1/00