Drycleaner Site Profiles

Fuller Supply, Concord, North Carolina

Description
Historical activity that resulted in contamination.

The facility previously stored and distributed PCE. The site is currently a drycleaning supply facility, but no longer supplies drycleaning solvents for resale. Drycleaning operations have not been performed on-site.

Remediation Status: In active remediation


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


Contaminant Media Concentration (ppb) Nondetect
Benzene groundwater
Benzene soil
cis-1,2-Dichloroethene groundwater
cis-1,2-Dichloroethene soil
1,2-Dichloroethane groundwater
1,1-Dichloroethene groundwater
ethylbenzene soil
Tetrachloroethene (PCE) groundwater
Tetrachloroethene (PCE) soil
Trichloroethene (TCE) groundwater
Trichloroethene (TCE) soil
Vinyl Chloride groundwater
Vinyl Chloride soil

Site Hydrology

Deepest Significant Groundwater Contamination:   120ft bgs
Plume Size:   Plume Length: 1,110ft
Plume Width: 470ft
Plume Thickness: 120ft
Average Depth to Groundwater:   8.75ft

Lithology and Subsurface Geology

 
  Mixture of sand, silt, and clay coarsening with depth to saprolite
Depth: 0-67.5ft bgs
67.5ft thick
Conductivity: 2.16ft/day
Gradient: 0.02ft/ft
 
  Plutonic bedrock
Depth: 67.5ft bgs

Pathways and DNAPL Presence

Groundwater
Sediments
Soil
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,Used an exposure screening model
Results of VI evaluation:
  A potential VI pathway has been indentified
Has a vapor mitigation system been installed?
  No 
Additional VI Information:
  Investigation is underway to evaluate whether indoor air impacts are associated with indoor source or VI.

Remediation Scenario

Cleanup Goals:
  Goal of interim action was to mitigate surface water impacts. Additional action to address possible VI concerns and stabilize plume have not yet been implemented.
Remedy Level:
  Interim Action

Technologies

In Situ Bioremediation
 

Why the technology was selected:
This technology was selected primarily based on a cost evaluation for various options.

Date implemented:
June 2009

Final remediation design:
A PRB was installed to mitigate stream impacts as an interim measure as described above. The final remedial design to address source area impacts has not yet been developed.

Other technologies used:
Anaerobic biochem plus (ABC+) was blended in-situ to form a PRB adjacent to an impacted stream. ABC+ consists of zero valent iron combined with a carbon substrate.

Results to date:
Significant reductions in contaminant concentrations were achieved in surface water and groundwater directly downgradient of the PRB. However, a portion of the plume appears to be flowing around the PRB so surface water remains impacted further downgradient.

Next Steps:
When funding is available, additional remedial actions will be planned to address source area impacts and remaining surface water impacts.

Cost to Design and Implement:
$154,864

In Situ Permeable Reactive Barriers (PRB)
 

Why the technology was selected:
This technology was selected primarily based on a cost evaluation for various options.

Date implemented:
June 2009

Final remediation design:
A PRB was installed to mitigate stream impacts as an interim measure as described above. The final remedial design to address source area impacts has not yet been developed.

Other technologies used:
Anaerobic biochem plus (ABC+) was blended in-situ to form a PRB adjacent to an impacted stream. ABC+ consists of zero valent iron combined with a carbon substrate.

Results to date:
Significant reductions in contaminant concentrations were achieved in surface water and groundwater directly downgradient of the PRB. However, a portion of the plume appears to be flowing around the PRB so surface water remains impacted further downgradient.

Next Steps:
When funding is available, additional remedial actions will be planned to address source area impacts and remaining surface water impacts.

Cost to Design and Implement:
$154,864

In Situ Zero Valent Iron
 

Why the technology was selected:
This technology was selected primarily based on a cost evaluation for various options.

Date implemented:
June 2009

Final remediation design:
A PRB was installed to mitigate stream impacts as an interim measure as described above. The final remedial design to address source area impacts has not yet been developed.

Other technologies used:
Anaerobic biochem plus (ABC+) was blended in-situ to form a PRB adjacent to an impacted stream. ABC+ consists of zero valent iron combined with a carbon substrate.

Results to date:
Significant reductions in contaminant concentrations were achieved in surface water and groundwater directly downgradient of the PRB. However, a portion of the plume appears to be flowing around the PRB so surface water remains impacted further downgradient.

Next Steps:
When funding is available, additional remedial actions will be planned to address source area impacts and remaining surface water impacts.

Cost to Design and Implement:
$154,864

Costs

Cost for Assessment:
  $335,388
Cost for Operation and Maintenance:
  $0
Total Costs for Cleanup:
  on-going

Lessons Learned

The PRB successfully addressed a portion of the plume discharging to the stream, but the PRB location and length should be carefully designed so the plume cannot flow around the PRB.

Contacts

Delonda Alexander, NC DSCA Program, 1646 Mail Service Center, Raleigh, North Carolina 27699-1646, (919) 707-8365, delonda.alexander@ncdenr.gov

Site Specific References

1/20/10 Interim Remedial Actions Activity Report, 4/4/11 Annual Groundwater Monitoring Report