State Coalition for Remediation of Drycleaners Site Profiles
Hangers Cleaners #68-0007, Carrboro, North Carolina
Description
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| The site is located in the central piedmont region of NC. The drycleaner operated from 1981 to 2006 and the building is a standalone single story slab on grade. A doctor's office now occupies the building. Remediation Status: In active remediation |
Contaminants
Contaminants present and the highest amount
detected in both soil and groundwater.
| Contaminant | Media | Concentration (ppb) | Nondetect |
|---|---|---|---|
| cis-1,2-Dichloroethene | groundwater | ||
| cis-1,2-Dichloroethene | soil | ||
| methylene chloride | groundwater | ||
| Tetrachloroethene (PCE) | groundwater | ||
| Tetrachloroethene (PCE) | soil | ||
| Trichloroethene (TCE) | groundwater | ||
| Trichloroethene (TCE) | soil | ||
| trans-1,2-Dichloroethene | groundwater | ||
| Vinyl Chloride | groundwater | ||
| Vinyl Chloride | soil |
Site Hydrology
| Deepest Significant Groundwater Contamination: | 200ft bgs | |
| Plume Size: | Plume Length: 735ft Plume Width: 400ft Plume Thickness: 200ft |
|
| Average Depth to Groundwater: | 13.18ft |
Lithology and Subsurface Geology
| Partially weathered parent rock of sand, silty sand, and clayey sands Depth: 0-25.5ft bgs 25.5ft thick Conductivity: 0.2834ft/day Gradient: 0.02ft/ft |
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| metamorphosed granitic bedrock Depth: 25.5ft bgs |
Pathways and DNAPL Presence
 GroundwaterSedimentsSoil Presumptive 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 |
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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 |
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Additional VI Information: |
Soil excavation and an SVE system were installed to address VI for on-site building prior to building used as a doctor's office. Additional assessment for off-site buildings indicated pathway complete, but levels indicated that no mitigation was required. |
Remediation Scenario
Cleanup
Goals: |
To reduce contaminant concentrations so that the site risks do not exceed a cumulative cancer risk of 1E-05 and a hazard index below 1.0. |
|
Remedy Level: |
Interim Action |
Technologies
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: |
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Ex Situ Soil Removal |
Why the technology was selected: Date implemented: Final remediation design: Results to date: Next Steps: Cost to Design and Implement: |
Costs
Cost
for Assessment: |
$431,128.63 | |
Cost
for Operation and Maintenance: |
Approximately $25,000.00 | |
Total
Costs for Cleanup: |
On-going |
Lessons Learned
| Excavation of impacted soil and installation of SVE piping concurrent with site redevelopment successfully addressed VI concerns for the new occupant (including a sensitive pediatrician's office) and helped further remediation efforts. |
Contacts
| Al Chapman, L.G. Project Manager DSCA Program NCDENR - Division of Waste Managment 1646 Mail Service Center Raleigh, NC 27699-1646 Phone: (919) 707-8368 Fax: (919) 707-8368 Email: Al.Chapman@ncdenr.gov Website: www.ncdsca.org |
Site Specific References
| The site reports are available on the NCDENR document portal system located at https://edm.nc.gov/DENR-Portal/ |
