Drycleaner Site Profiles

Comet Cleaners, Arlington, Texas

Description
Historical activity that resulted in contamination.

The site and surrouding area have been used for both residential and commercial/industrial purposes. In the early to mid 1900s, the site was mainly residential, but by 1984 it was verified as a commercial site. Dry cleaning operations have been conducteds in one lease space on the strip mall property for approximately 10 years, beginning around 1994. Chlorinated solvents were used in the past.

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
Tetrachloroethene (PCE) groundwater
Trichloroethene (TCE) groundwater
Vinyl Chloride groundwater

Site Hydrology

Deepest Significant Groundwater Contamination:   12ft bgs
Plume Size:   Plume Length: 375ft
Plume Width: 40ft
Average Depth to Groundwater:   11ft

Lithology and Subsurface Geology

 
  moderate to high plasticity clay with some 30% sand

Pathways and DNAPL Presence

Groundwater
Sediments
Soil
checkPresumptive Evidence of DNAPL

Vapor Intrusion Pathway

Has the potential for vapor intrusion (VI) been evaluated?
  No
Has a vapor mitigation system been installed?
   

Remediation Scenario

Cleanup Goals:
  *The soil cleanup goals were&
PCE 5 mg/kg
TCE 3.4 mg/kg
cisDCE 25 mg/kg
VC 2.2 mg/kg

(Note: this is 100x the soil to gw PCLs for GW Class 1 and 2 situations)


GW clean up goals: MCLs x100
Remedy Level:
  Interim Action

Technologies

In Situ Chemical Oxidation
 

Why the technology was selected:
*FY10 ISCO Pilot was used to decided is Chem-ox remedial treatments in larger dosages would be effective.

Date implemented:
FY10 ISCO Pilot (Jan. 5-8, 2010)

Final remediation design:
*FY10 ISCO Pilot (Chem-ox): This remediation event injected at approximately 175 gallons of 10% sodium permanganate at six points. Each injected point was hydraulically fractured prior to injection.

Results to date:
Groundwater concentrations were non-detect immediately following the injection, but PCE concentrations rebounded to 0.92 mg/L 18 months after the injection.

Next Steps:
Continued groundwater monitoring. An additional round of ISCO or bioaugmentation may also be performed.

In Situ Monitored Natural Attenuation
 

Why the technology was selected:
*FY11 MNA was used because it was the most cost effective choice of remediation for this site.

Date implemented:
*FY11 MNA

Results to date:
Groundwater concentrations were non-detect immediately following the injection, but PCE concentrations rebounded to 0.92 mg/L 18 months after the injection.

Next Steps:
Continued groundwater monitoring. An additional round of ISCO or bioaugmentation may also be performed.

Costs

Cost for Assessment:
 
Cost for Operation and Maintenance:
 
Total Costs for Cleanup:
  $93,614 (cost includes FY10 ISCO Pilot and 5 GW monitoring events post the remediation)

Lessons Learned

The ISCO Pilot study proved that chem-ox remediation is effective in the short term, but may require more than one treatment to meet clean up goals.

Contacts

Dan Switek
PST / DCRP Section
Remediation Division
Texas Commission on Environmental Quality (TCEQ)
dan.switek@tceq.texas.gov
512-239-4132