Drycleaner Site Profiles

Stanton Cleaners Area Groundwater Contamination Site, Great Neck, Nassau County, New York

Description
Historical activity that resulted in contamination.

Stanton Dry Cleaners is an active facility that has existed since 1958. The site is approximately 1/4 of an acre in size. The site is located in a mixed commercial/residential area. Immediately adjacent properties include a tennis facility, a school facility, a synagogue, a condominium, and a service station. Three public drinking water supply wells are located approximately 1,000 ft from the Stanton Cleaners site.

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


Contaminant Media Concentration (ppb) Nondetect
Tetrachloroethene (PCE) groundwater 18,000 ppb
Tetrachloroethene (PCE) soil 40,000,000 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:   100ft bgs
Plume Size:  
Average Depth to Groundwater:   70ft

Lithology and Subsurface Geology

Upper Glacial
  fine to coarse layers of sand and gravel, boulders and clay
Depth: 0-132ft bgs
132ft thick
Conductivity: 1234ft/day
Gradient: 0.0112ft/ft
Magothy
  layers of fine sands, clays, silts and some course beds of sands and gravel
Depth: 132ft bgs
Lloyd
  sand
 
  bedrock

Pathways and DNAPL Presence

checkGroundwater
Sediments
checkSoil
DNAPL Present

Remediation Scenario

Cleanup Goals:
  Reduce, control or eliminate contaminants in soil and groundwater to the maximum extent practicable; restore the aquifer to its best beneficial use; eliminate the potential for human exposure to contaminated site groundwater, soil, and indoor air.

Technologies

In Situ Soil Vapor Extraction
 

Date implemented:
1998

Final remediation design:
PCE levels in soil vapor that exceeded the New York State Dept. of Health guidance values for concern (100 µg/m3) and immediate action (1,000 µg/m3) were detected in the neighboring tennis facility and synagogue. In 1989 a groundwater extraction and treatment system was installed to address groundwater contamination migrating from the site. In September 1998, vapor migration controls (venting system) were installed to prevent PCE from migrating into the tennis structure and parking garage. In December 1998, a soil vapor extraction (SVE) system was installed to further mitigate indoor air impacts and for PCE source removal. In 1999, a Record of Decision was issued that required continued operation of the SVE system, upgrade of the groundwater extraction system to address groundwater contamination on the site, monitoring of indoor air, long term groundwater monitoring, and groundwater use restrictions. An additional study for other sources of groundwater contamination is planned.

Results to date:
Immediate - Implementation of the SVE and venting systems resulted in the reduction of PCE levels in the adjacent structures to acceptable levels. In 2002, an EPA removal action was performed for the removal of underground PCE storage tanks. Soil - Operation of the SVE system for PCE source removal resulted in removal of approximately 16,000 lbs of PCE as of May 2002. The current rate of mass removal is approx. 1 pound per day.

Next Steps:
Soil - Continued operation of the SVE system for PCE source removal. The pump and treat system will continue to operate as well. Periodic indoor air sampling will also be performed.

Cost to Design and Implement:
all technologies: Interim Remedial Measure - $1,300,000 (implementation and operation of Soil-Vapor Extraction System) Design and Implementation - $ 1,000,000 (includes Operable Unit 2)

Ex Situ Air Stripping
 

Date implemented:
1998

Final remediation design:
PCE levels in soil vapor that exceeded the New York State Dept. of Health guidance values for concern (100 µg/m3) and immediate action (1,000 µg/m3) were detected in the neighboring tennis facility and synagogue. In 1989 a groundwater extraction and treatment system was installed to address groundwater contamination migrating from the site. In September 1998, vapor migration controls (venting system) were installed to prevent PCE from migrating into the tennis structure and parking garage. In December 1998, a soil vapor extraction (SVE) system was installed to further mitigate indoor air impacts and for PCE source removal. In 1999, a Record of Decision was issued that required continued operation of the SVE system, upgrade of the groundwater extraction system to address groundwater contamination on the site, monitoring of indoor air, long term groundwater monitoring, and groundwater use restrictions. An additional study for other sources of groundwater contamination is planned.

Results to date:
Immediate - Implementation of the SVE and venting systems resulted in the reduction of PCE levels in the adjacent structures to acceptable levels. In 2002, an EPA removal action was performed for the removal of underground PCE storage tanks. Soil - Operation of the SVE system for PCE source removal resulted in removal of approximately 16,000 lbs of PCE as of May 2002. The current rate of mass removal is approx. 1 pound per day. Groundwater - Interim groundwater P&T was operational using portable system and pumping IW-01 interceptor well. Approximately 750,000 gallons pumped @ 15 gpm. A new groundwater extraction system was placed on-line October 2001 and treats 50 to 65 gpm. As of 2002, OCE concentrations have dropped more thsn 5-fold.

Next Steps:
Soil - Continued operation of the SVE system for PCE source removal. The pump and treat system will continue to operate as well. Periodic indoor air sampling will also be performed.

Cost to Design and Implement:
all technologies: Interim Remedial Measure - $1,300,000 (implementation and operation of Soil-Vapor Extraction System) Design and Implementation - $ 1,000,000 (includes Operable Unit 2)

Ex Situ Pump and Treat
 

Date implemented:
1998

Final remediation design:
PCE levels in soil vapor that exceeded the New York State Dept. of Health guidance values for concern (100 µg/m3) and immediate action (1,000 µg/m3) were detected in the neighboring tennis facility and synagogue. In 1989 a groundwater extraction and treatment system was installed to address groundwater contamination migrating from the site. In September 1998, vapor migration controls (venting system) were installed to prevent PCE from migrating into the tennis structure and parking garage. In December 1998, a soil vapor extraction (SVE) system was installed to further mitigate indoor air impacts and for PCE source removal. In 1999, a Record of Decision was issued that required continued operation of the SVE system, upgrade of the groundwater extraction system to address groundwater contamination on the site, monitoring of indoor air, long term groundwater monitoring, and groundwater use restrictions. An additional study for other sources of groundwater contamination is planned.

Results to date:
Groundwater - Interim groundwater P&T was operational using portable system and pumping IW-01 interceptor well. Approximately 750,000 gallons pumped @ 15 gpm. A new groundwater extraction system was placed on-line October 2001 and treats 50 to 65 gpm. As of 2002, OCE concentrations have dropped more thsn 5-fold.

Next Steps:
Soil - Continued operation of the SVE system for PCE source removal. The pump and treat system will continue to operate as well. Periodic indoor air sampling will also be performed.

Cost to Design and Implement:
all technologies: Interim Remedial Measure - $1,300,000 (implementation and operation of Soil-Vapor Extraction System) Design and Implementation - $ 1,000,000 (includes Operable Unit 2)

Costs

Cost for Assessment:
  $302,000 (RI/FS)
Cost for Operation and Maintenance:
  $ 450K for two years, then $ 225K for the next 18 years
Total Costs for Cleanup:
 

Lessons Learned

1. Implementation of SVE system immediately reduced indoor levels from surrounding structures to acceptable levels.
2. High source removal (approximately 16,000 lbs of PCE) is suggested to have reduced the proposed groundwater extraction system operation time. PCE pumping concentrations in groundwater have steadily been reduced within a short pumping period.

Contacts

Jim Harrington
New York Department of Environmental Conservation
11th Floor
625 Broadway
Albany, New York 12233-7012
518-402-9755
518-402-9722 (fax)
jbharrin@gw.dec.state.ny.us

Site Specific References

1. Site Investigation and Remedial Option Evaluation, Stanton Cleaners, Sept 1886
2. Remedial Investigation/ Feasibility Study Workplan, Stanton Cleaners, April 1997
3. Remedial Investigation/Feasibility Study Workplan, Stanton Cleaners, May 1998
4. Remedial Investigation/Feasibility Study Report, Stanton Cleaners, January 1999
5. Proposed Remedial Action Plan, Stanton Cleaners, February 1999
6. Record of Decision, Stanton Cleaners, March 1999