State Coalition for Remediation of Drycleaners Site Profiles
Williams/Hangers Cleaners, Wilmington, North Carolina
Description
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| The property was developed with the present-day building structure in 1983 as a drycleaner. According to historical information (aerial photographs and city directories) the subject property was undeveloped prior to 1983. Tetrachloroethylene (PCE) was reportedly utilized as a drycleaning solvent from 1983 through 1997. In 1997, drycleaning operations on site were discontinued until 2001. During the period 1997 through 2001, the facility was used as a drop-off location only. In 2001 new petroleum-based drycleaning equipment was installed. Since 2001 (through present day) the facility has used Exxon DF-2000 (petroleum-based) drycleaning solvent. The name of the drycleaner changed from Williams Cleaners to Hangers Cleaners at an unknown date. Remediation Status: In groundwater monitoring |
Contaminants
Contaminants present and the highest amount
detected in both soil and groundwater.
| Contaminant | Media | Concentration (ppb) | Nondetect |
|---|---|---|---|
| Benzene | groundwater | ||
| cis-1,2-Dichloroethene | groundwater | ||
| 1,2-Dichloroethane | groundwater | ||
| Tetrachloroethene (PCE) | groundwater | ||
| Tetrachloroethene (PCE) | soil | ||
| Trichloroethene (TCE) | groundwater | ||
| Vinyl Chloride | groundwater |
Site Hydrology
| Deepest Significant Groundwater Contamination: | 40ft bgs | |
| Plume Size: | Plume Length: 128ft Plume Width: 68ft Plume Thickness: 40ft |
|
| Average Depth to Groundwater: | 10.73ft |
Lithology and Subsurface Geology
| Interbedded silty sand, clayey sand, and fine to medium grained sand Conductivity: 0.016ft/day Gradient: 0.01ft/ft |
Pathways and DNAPL Presence
 GroundwaterSedimentsSoilDNAPL Present |
Vapor Intrusion Pathway
Has the potential for vapor intrusion (VI) been evaluated? |
Yes |
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How was the site evaluated? |
Soil vapor and/or Sub-slab vapor sampling,Groundwater sampling,Compared sample concentration to screening criteria,Used an exposure screening model |
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Results of VI evaluation: |
A potential VI pathway has been indentified | |
Has a vapor mitigation system been installed? |
Yes | |
Type of Vapor Mitigation System(s): |
Soil Vapor Extraction |
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Additional VI Information: |
Indoor air sampling was not performed since drycleaning is actively performed in the on-site building. However, modeling indicated a potential risk of VI. An air sparge/soil vapor extraction system was installed to remediate source area impacts which posed a possible VI risk. |
Remediation Scenario
Cleanup
Goals: |
The cleanup goals are to reduce source area concentrations sufficient to achieve plume stability and reduce the VI risk. |
|
Remedy Level: |
Full Scale Remedy |
Technologies
In Situ Air Sparging |
Why the technology was selected: Date implemented: Final remediation design: Results to date: Next Steps: Cost to Design and Implement: |
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In Situ Soil Vapor Extraction |
Why the technology was selected: Date implemented: Final remediation design: Results to date: Next Steps: Cost to Design and Implement: |
Costs
Cost
for Assessment: |
$155,643 | |
Cost
for Operation and Maintenance: |
$70,548 | |
Total
Costs for Cleanup: |
On-going |
Lessons Learned
| Installation of an AS/SVE system successfully reduced source area contaminant concentrations. |
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
| 9/20/10 Soil Gas Sampling Report, 7/16/10 Remediation System Operation & Maintenance Report, and 5/31/10 Annual Groundwater Monitoring Report |
