Drycleaner Site Profiles

Crown Cleaners, Spring Lake, North Carolina

Description
Historical activity that resulted in contamination.

The site reportedly operated as a dry-cleaner from the mid-1940's to 2005. The site's original structure is currenly unoccupied and is located in the coastal plain near Fayetteville, NC. Significant soil and groundwater contamination was discovered during an initial investigation and it was then brought into the program. The owner has indicated that he plans to renovate the building and open a restaurant at some point. Vapor intrusion is a concern and indoor air concentrations exceeded the mitigation threshold. Several remedial options were examined but SVE was chosen due to building structure issues and amenable soils (sands with some interspersed silty/clayey sands). In addition, a passive subslab depressurization system was installed to improve indoor air quality.

Remediation Status: In active remediation


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


Contaminant Media Concentration (ppb) Nondetect
chloroform groundwater 3.4 ppb
cis-1,2-Dichloroethene groundwater 96 ppb
Tetrachloroethene (PCE) soil 24,000 ppb
Trichloroethene (TCE) soil 2.3 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:   34ft bgs
Plume Size:   Plume Length: 1,000ft
Plume Width: 600ft
Plume Thickness: 25ft
Average Depth to Groundwater:   28ft

Lithology and Subsurface Geology

Surficial/Black Creek (unconfined)
  Layered sand with clayey sand and sandy clay stringers.
Depth: 0-43ft bgs
43ft thick
Conductivity: 0.085ft/day
Gradient: 0.03ft/ft

Pathways and DNAPL Presence

checkGroundwater
Sediments
checkSoil
checkPresumptive Evidence of DNAPL

Vapor Intrusion Pathway

Has the potential for vapor intrusion (VI) been evaluated?
  Yes
How was the site evaluated?
  Soil vapor and/or Sub-slab vapor sampling,Indoor air sampling,Groundwater sampling,Compared sample concentration to screening criteria
Results of VI evaluation:
  A completed VI pathway has been indentified
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:
  Soil: 0.18 mg/kg PCE
Remedy Level:
  Interim Action

Technologies

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Soil Vapor Extraction
 

Why the technology was selected:
This option was chosen based on site suitability and building condition (hotspot was beneath primary load bearing wall that is not in good condition)

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Three deep field and three shallow field SVE wells were installed and plumbed to a single SVE blower housed in an exterior shed. The system allows for operation of combined or indepentent operation of the fields as necessary.

Results to date:
Remediation is still ongoing, but SVE offgas concentrations of PCE have decreased from 1,400 mg/m3 to 46 mg/m3.

Next Steps:
Based on next O&M visit the offgas sample results will be used to determine if the system should continue operating or be shut down.

Cost to Design and Implement:
115,668.00

in Situ Vapor Mitigation
 

Why the technology was selected:
Passive subslab depressurization was selected based on subslab concentrations and ease of installation in concert with the SVE system.

Date implemented:
August 6, 2012

Date completed:
Ongoing

Final remediation design:
Shallow perforated PVC piping was installed underneath the slab above the SVE piping and runs to exterior passive turbine fans.

Results to date:
Ongoing - will check indoor air prior to and once building is reoccupied.

Next Steps:
As above - Once SVE system has reached apparent asymptotic levels we will shut the system down and test the indoor air. If there is still an issue the passive system will remain operational and if the building becomes re-occupied then the passive system may be made active.

Cost to Design and Implement:
The passive system was incorporated as part of the SVE system cost above.

Costs

Cost for Assessment:
  131447
Cost for Operation and Maintenance:
  29567
Total Costs for Cleanup:
 

Lessons Learned

Even though the pilot test indicated good suitability for SVE, infiltrating precipitation has caused the knockout tanks to fill up prematurely. The solution was to cycle the shallow and deep well fields periodically.











Contacts

Mike Cunningham, NC DSCA Program 217 W. Jones St. Raleigh, NC 27603 (919) 707-8361 mike.cunningham@ncdenr.gov