Drycleaner Site Profiles

W.P. Ballard, Durham, North Carolina

Description
Historical activity that resulted in contamination.

W.P. Ballard operated as a wholesale dry-cleaning supply business until 2001. Tetrachloroethylene (PCE) was stored for retail distribution in a 5,000-gallon aboveground storage tank (AST). Approximately 3,500 gallons of PCE were released from the AST in August 1997. Since 2009, the facility has been occupied by US Car Tool, a custom car fabrication business.

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
chloroform groundwater
cis-1,2-Dichloroethene groundwater
1,1-Dichloroethene groundwater
Tetrachloroethene (PCE) groundwater
Tetrachloroethene (PCE) soil
naphthalene groundwater
Trichloroethene (TCE) groundwater
Trichloroethene (TCE) soil
trans-1,2-Dichloroethene groundwater
Vinyl Chloride groundwater
Vinyl Chloride soil

Site Hydrology

Deepest Significant Groundwater Contamination:   105ft bgs
Plume Size:   Plume Length: 1,550ft
Plume Width: 800ft
Plume Thickness: 105ft
Average Depth to Groundwater:   21.32ft

Lithology and Subsurface Geology

 
  Interbedded layers of grey, brown, and reddish brown sandy silt, silty sand, silty clay, silt, and clay
Depth: 0-17.5ft bgs
17.5ft thick
Conductivity: 0.2575ft/day
Gradient: 0.029ft/ft
 
  siltstone with some interbedded mudstone, sandstone, and sandy siltstone
Depth: 17.5ft bgs

Pathways and DNAPL Presence

Groundwater
Sediments
Soil
checkDNAPL Present

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 completed VI pathway has been indentified
Has a vapor mitigation system been installed?
  Yes 
Type of Vapor Mitigation System(s):
  Sub-slab Depressurization
Soil Vapor Extraction
Additional VI Information:
  Soil excavation and an SVE system were installed to address VI for on-site building.

Remediation Scenario

Cleanup Goals:
  The cleanup goals are attainment of acceptable risk levels in on-site indoor air and demonstration of plume stability.
Remedy Level:
  Interim Action

Technologies

In Situ Bioremediation
 

Why the technology was selected:
Removal of accessible impacted soil was determined to be most effective method of source removal and was conducted concurrent with in-situ placement of EZVI. Ongoing injection activities are underway to reduce source area concentrations and minimize further off-site plume migration utilizing three permeable reactive barriers (PRBs).

Date implemented:
The soil excavation was completed in November 2008 through January 2009 and consisted of removing 1,173.95 tons. The SVE system began operation in August 2010 and was upgraded in February 2012. In April 2011, approximately 675 gallons of IET's injection

Final remediation design:
SVE is expected to continue as an interim action to address VI concerns. Additional groundwater injection is also planned to achieve cleanup goals.

Other technologies used:
Reductive dechlorination by placing emulsified zero valent iron (EZVI) in a soil excavation and injecting a mixture of EZVI, ZVI, kelp, blue green algae, calcium propionate, and sodium sulfite. The injectate mixture and proposed injection process were designed by Innovative Environmental Technologies (IET).

Results to date:
As of March 2012, air sampling had confirmed the reduction of PCE concentrations in indoor air. Additional contaminant mass was also removed during excavation of 1,173.95 tons of impacted soil. Results of the pre and post-injection groundwater sampling suggest that the pilot phase injection activities have successfully reduced contaminant concentrations within the injection area.

Next Steps:
To address VI concerns, the SVE system will continue to run while sampling indoor air on a semi-annual basis. In addition, groundwater sampling will continue on a quarterly basis while implementing full scale injection activities.

Cost to Design and Implement:
$1,303,667 for all technologies

In Situ Permeable Reactive Barriers (PRB)
 

Why the technology was selected:
Ongoing injection activities are underway to reduce source area concentrations and minimize further off-site plume migration utilizing three permeable reactive barriers (PRBs).

Date implemented:
The soil excavation was completed in November 2008 through January 2009 and consisted of removing 1,173.95 tons. The SVE system began operation in August 2010 and was upgraded in February 2012. In April 2011, approximately 675 gallons of IET's injection

Final remediation design:
SVE is expected to continue as an interim action to address VI concerns. Additional groundwater injection is also planned to achieve cleanup goals.

Other technologies used:
Reductive dechlorination by placing emulsified zero valent iron (EZVI) in a soil excavation and injecting a mixture of EZVI, ZVI, kelp, blue green algae, calcium propionate, and sodium sulfite. The injectate mixture and proposed injection process were designed by Innovative Environmental Technologies (IET).

Results to date:
As of March 2012, air sampling had confirmed the reduction of PCE concentrations in indoor air. Additional contaminant mass was also removed during excavation of 1,173.95 tons of impacted soil. Results of the pre and post-injection groundwater sampling suggest that the pilot phase injection activities have successfully reduced contaminant concentrations within the injection area.

Next Steps:
To address VI concerns, the SVE system will continue to run while sampling indoor air on a semi-annual basis. In addition, groundwater sampling will continue on a quarterly basis while implementing full scale injection activities.

Cost to Design and Implement:
$1,303,667 for all technologies

In Situ Soil Vapor Extraction
 

Why the technology was selected:
Soil vapor extraction (SVE) was selected to address impacted soil that could not be removed due to structural considerations while concurrently mitigating vapor intrusion by depressurization. In addition, ongoing injection activities are underway to reduce source area concentrations and minimize further off-site plume migration utilizing three permeable reactive barriers (PRBs).

Date implemented:
The soil excavation was completed in November 2008 through January 2009 and consisted of removing 1,173.95 tons. The SVE system began operation in August 2010 and was upgraded in February 2012. In April 2011, approximately 675 gallons of IET's injection

Final remediation design:
SVE is expected to continue as an interim action to address VI concerns. Additional groundwater injection is also planned to achieve cleanup goals.

Results to date:
As of March 2012, air sampling had confirmed the reduction of PCE concentrations in indoor air. Additional contaminant mass was also removed during excavation of 1,173.95 tons of impacted soil. Results of the pre and post-injection groundwater sampling suggest that the pilot phase injection activities have successfully reduced contaminant concentrations within the injection area.

Next Steps:
To address VI concerns, the SVE system will continue to run while sampling indoor air on a semi-annual basis. In addition, groundwater sampling will continue on a quarterly basis while implementing full scale injection activities.

Cost to Design and Implement:
$1,303,667 for all technologies

In Situ Vapor Mitigation
 

Why the technology was selected:
Soil vapor extraction (SVE) was selected to address impacted soil that could not be removed due to structural considerations while concurrently mitigating vapor intrusion by depressurization.

Date implemented:
The soil excavation was completed in November 2008 through January 2009 and consisted of removing 1,173.95 tons. The SVE system began operation in August 2010 and was upgraded in February 2012. In April 2011, approximately 675 gallons of IET's injection

Final remediation design:
SVE is expected to continue as an interim action to address VI concerns. Additional groundwater injection is also planned to achieve cleanup goals.

Other technologies used:
Reductive dechlorination by placing emulsified zero valent iron (EZVI) in a soil excavation and injecting a mixture of EZVI, ZVI, kelp, blue green algae, calcium propionate, and sodium sulfite. The injectate mixture and proposed injection process were designed by Innovative Environmental Technologies (IET).

Results to date:
As of March 2012, air sampling had confirmed the reduction of PCE concentrations in indoor air. Additional contaminant mass was also removed during excavation of 1,173.95 tons of impacted soil. Results of the pre and post-injection groundwater sampling suggest that the pilot phase injection activities have successfully reduced contaminant concentrations within the injection area.

Next Steps:
To address VI concerns, the SVE system will continue to run while sampling indoor air on a semi-annual basis. In addition, groundwater sampling will continue on a quarterly basis while implementing full scale injection activities.

Cost to Design and Implement:
$1,303,667 for all technologies

In Situ Zero Valent Iron
 

Why the technology was selected:
Removal of accessible impacted soil was determined to be most effective method of source removal and was conducted concurrent with in-situ placement of EZVI.

Date implemented:
The soil excavation was completed in November 2008 through January 2009 and consisted of removing 1,173.95 tons. The SVE system began operation in August 2010 and was upgraded in February 2012. In April 2011, approximately 675 gallons of IET's injection

Final remediation design:
SVE is expected to continue as an interim action to address VI concerns. Additional groundwater injection is also planned to achieve cleanup goals.

Other technologies used:
Reductive dechlorination by placing emulsified zero valent iron (EZVI) in a soil excavation and injecting a mixture of EZVI, ZVI, kelp, blue green algae, calcium propionate, and sodium sulfite. The injectate mixture and proposed injection process were designed by Innovative Environmental Technologies (IET).

Results to date:
As of March 2012, air sampling had confirmed the reduction of PCE concentrations in indoor air. Additional contaminant mass was also removed during excavation of 1,173.95 tons of impacted soil. Results of the pre and post-injection groundwater sampling suggest that the pilot phase injection activities have successfully reduced contaminant concentrations within the injection area.

Next Steps:
To address VI concerns, the SVE system will continue to run while sampling indoor air on a semi-annual basis. In addition, groundwater sampling will continue on a quarterly basis while implementing full scale injection activities.

Cost to Design and Implement:
$1,303,667 for all technologies

Ex Situ Soil Removal
 

Why the technology was selected:
Removal of accessible impacted soil was determined to be most effective method of source removal and was conducted concurrent with in-situ placement of EZVI.

Date implemented:
The soil excavation was completed in November 2008 through January 2009 and consisted of removing 1,173.95 tons. The SVE system began operation in August 2010 and was upgraded in February 2012. In April 2011, approximately 675 gallons of IET's injection

Final remediation design:
SVE is expected to continue as an interim action to address VI concerns. Additional groundwater injection is also planned to achieve cleanup goals.

Results to date:
As of March 2012, air sampling had confirmed the reduction of PCE concentrations in indoor air. Additional contaminant mass was also removed during excavation of 1,173.95 tons of impacted soil. Results of the pre and post-injection groundwater sampling suggest that the pilot phase injection activities have successfully reduced contaminant concentrations within the injection area.

Next Steps:
To address VI concerns, the SVE system will continue to run while sampling indoor air on a semi-annual basis. In addition, groundwater sampling will continue on a quarterly basis while implementing full scale injection activities.

Cost to Design and Implement:
$1,303,667 for all technologies

Costs

Cost for Assessment:
  $768,506
Cost for Operation and Maintenance:
  $52,650
Total Costs for Cleanup:
  On-going

Lessons Learned

Excavation of impacted soil and concurrent installation of SVE piping is successfully addressing VI concerns. IET's injection mixture has also proved effective for groundwater remediation.

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

4/15/09 Soil Excavation & In Situ Remediation Letter Report, 8/5/11 Annual Groundwater Monitoring Report