Drycleaner Site Profiles

Gaffney Road West / Royal Master Laundrette, Fairbanks, Alaska

Description
Historical activity that resulted in contamination.

Former dry cleaner PCE, TCE, and DCE contaminants in soil and groundwater from former dry cleaning operation. Soil and groundwater contamination at the southwest corner of the building is causing vapor intrusion. This site is the current location of the Good News Bible and Bookstore on Gaffney Road. There has been a settlement agreement with the responsible parties, including the current owner and the former owner, who operated the dry cleaning facility. Former drycleaners operations likely involved solvent disposal to soil and/or wood stave sewer lines, which contaminated the surrounding groundwater This site containsis one of three three source areas that are believed to create a comingling plume: two just south of Airport Way between Cushman and Turner streets, and one north of Airport Way along Stacia Street. These areas of elevated chlorinated solvent concentrations are found along sewer lines. The investigations to date have shown the plume does not extend to the city drinking water wells (based on the sole source aquifer), which are approximately 1/2-mile downgradient of the site.

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
Tetrachloroethene (PCE) groundwater
Tetrachloroethene (PCE) soil
Trichloroethene (TCE) groundwater
Trichloroethene (TCE) soil
trans-1,2-Dichloroethene groundwater
trans-1,2-Dichloroethene soil

Site Hydrology

Deepest Significant Groundwater Contamination:   50ft bgs
Plume Size:   Plume Length: 3,500ft
Plume Width: 500ft
Plume Thickness: 36ft
Average Depth to Groundwater:   14ft

Lithology and Subsurface Geology

 
  Silty sand with gravel
Depth: 1-3ft bgs
2ft thick
Gradient: 0.001ft/ft
 
  silt or silty sand (sometimes with gravel)
Depth: 3ft 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 completed VI pathway has been indentified,A potential 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:
  Combined sub-slab depressurization and soil vapor extraction (SSD/SVE ) system, with three SSD and 16 SVE wells, in operation since January 2010.

Remediation Scenario

Cleanup Goals:
  Groundwater (µg/L) : PCE = 5, TCE = 5, cis-1,2-DCE = 70, trans-1,2-DCE = 100
Soil (µg/kg): PCE = 24, TCE = 20, cis-1,2-DCE = 240, trans-1,2-DCE = 370
Indoor Air, Commercial (µg/m3): PCE = 21, TCE = 1.1, cis-1,2-DCE = 150, trans-1,2-DCE = 260
Sub-Slab Soil Gas, Commercial (µg/m3): PCE = 210, TCE = 11, cis-1,2-DCE = 1500, trans-1,2-DCE = 2600

Remedy Level:
  Full Scale Remedy

Technologies

In Situ Monitored Natural Attenuation
 

Date implemented:
SSD/SVE since 2010 Groundwater MNA since discovery

Results to date:
The SSD system is successfully meeting remedial action objectives by mitigating vapor intrusion to an on-site business through elimination of positive pressure beneath the building slab. The SVE system is expected to reduce contaminant concentrations in vadose zone soils. Indoor air and sub-slab samples are below target levels for PCE and TCE since the system has been operating.

Next Steps:
The SSD system could be expanded by adding sub-slab extraction wells to an adjacent business property that has shown indoor air levels near the target levels . The SVE system should be adjusted to pulsed operation as contamination removal becomes diffusion-limited and exhaust stack concentrations near indoor air target levels. Groundwater remediation may be pursued.

Cost to Design and Implement:
$405,000 (all technologies)

In Situ Soil Vapor Extraction
 

Why the technology was selected:
Through settlement agreement with Responsible Parties; SSD/SVE designed to treat contaminant source in soil and to mitigate vapor intrusion into affected properties.

Date implemented:
SSD/SVE since 2010 Groundwater MNA since discovery

Other technologies used:
Combined sub-slab depressurization and soil vapor extraction (SSD/SVE ) system, with three SSD and 16 SVE wells, in operation since January 2010.

Results to date:
The SSD system is successfully meeting remedial action objectives by mitigating vapor intrusion to an on-site business through elimination of positive pressure beneath the building slab. The SVE system is expected to reduce contaminant concentrations in vadose zone soils. Indoor air and sub-slab samples are below target levels for PCE and TCE since the system has been operating.

Next Steps:
The SSD system could be expanded by adding sub-slab extraction wells to an adjacent business property that has shown indoor air levels near the target levels . The SVE system should be adjusted to pulsed operation as contamination removal becomes diffusion-limited and exhaust stack concentrations near indoor air target levels. Groundwater remediation may be pursued.

Cost to Design and Implement:
$405,000 (all technologies)

In Situ Other
 

Why the technology was selected:
Through settlement agreement with Responsible Parties; SSD/SVE designed to treat contaminant source in soil and to mitigate vapor intrusion into affected properties.

Date implemented:
SSD/SVE since 2010 Groundwater MNA since discovery

Other technologies used:
Combined sub-slab depressurization and soil vapor extraction (SSD/SVE ) system, with three SSD and 16 SVE wells, in operation since January 2010.

Results to date:
The SSD system is successfully meeting remedial action objectives by mitigating vapor intrusion to an on-site business through elimination of positive pressure beneath the building slab. The SVE system is expected to reduce contaminant concentrations in vadose zone soils. Indoor air and sub-slab samples are below target levels for PCE and TCE since the system has been operating.

Next Steps:
The SSD system could be expanded by adding sub-slab extraction wells to an adjacent business property that has shown indoor air levels near the target levels . The SVE system should be adjusted to pulsed operation as contamination removal becomes diffusion-limited and exhaust stack concentrations near indoor air target levels. Groundwater remediation may be pursued.

Cost to Design and Implement:
$405,000 (all technologies)

Costs

Cost for Assessment:
  Unknown (likely > $1,000,000)
Cost for Operation and Maintenance:
  $150,000
Total Costs for Cleanup:
  Unknown

Contacts

Tamara Cardona-Marek, PhD
Contaminated Sites Program
Alaska Department of Environmental Conservation
611 University Ave
Fairbanks, AK 99709
Phone: (907) 451-2192
Email: tamara.cardona-marek@alaska.gov


Site Specific References

http://dec.alaska.gov/spar/csp/sites/gaffney.htm