U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

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U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

State Coalition for Remediation of Drycleaners Site Profiles

Former Plus Cleaners, Houston, Texas

Historical activity that resulted in contamination.

The facility, located within a shopping center, was constructed in 1984. Plus Cleaners operated a dry cleaning plant using perchloroethylene/ tetrachloroethylene (PCE) as the dry cleaning solvent in a dry-to-dry machine. According to available reports, Plus Cleaners removed the dry cleaning equipment in November 1997. The site was registered as a dry cleaning facility through September 30,2007, however no drycleaning activities were reported to have occured after 1997. Investigations revealed that poor housekeeping procedures and improper handling of dry cleaning chemicals at the Plus Cleaners facility resulted in the release of dry cleaning chemicals (PCE) into the storm sewer drain and catch basin. Numerous site investigations have been conducted at this site since September 1994 including the installation of multiple groundwater monitoring wells and soil borings. Prior to enrollment in the DCRP in 2007, multiple response actions were completed at the property including groundwater extraction and treatment, 2 different soil removal actions, and in-situ chemical oxidation events.

Remediation Status: In active remediation

Contaminants present and the highest amount detected in both soil and groundwater.

Contaminant Media Concentration (ppb) Nondetect
cis-1,2-Dichloroethene groundwater 38 ppb
Tetrachloroethene (PCE) groundwater 29 ppb
Trichloroethene (TCE) groundwater 12 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:   27ft bgs
Plume Size:   Plume Length: 450ft
Plume Width: 100ft
Plume Thickness: 10ft
Average Depth to Groundwater:   17.5ft

Lithology and Subsurface Geology

  Silty clay. The upper groundwater bearing unit (GWBU) at the subject property occurs between approximately 16 to 27-feet bgs. The zone is described as silty clay.
Depth: 0-25ft bgs
25ft thick
Conductivity: 0.017ft/day
  Silt, clayey in MW-1, MW-3, and MW-6. The upper groundwater bearing unit (GWBU) at the subject property occurs between approximately 16 to 27-feet bgs. The zone is described as silty clay.
Depth: 18-27ft bgs
9ft thick
Conductivity: 0.017ft/day
  Sand, silty, slightly clayey, wet
Depth: 27-47ft bgs
20ft thick
Conductivity: 0.017ft/day
Depth: 44-47ft bgs
3ft thick
Conductivity: 0.017ft/day

Pathways and DNAPL Presence

DNAPL Present

Vapor Intrusion Pathway

Has the potential for vapor intrusion (VI) been evaluated?
Has a vapor mitigation system been installed?

Remediation Scenario

Cleanup Goals:
  Reduce contaminant levels below MCL
Remedy Level:
  Interim Action


In Situ Bioremediation

Why the technology was selected:
Bio-augmentation was selected at this site because of the natural favorabilty towards this type of remediation. Because PCE daughter products were present, augmenting natural processes was a sensible technology.

Date implemented:
August 2011

Final remediation design:
Three in-situ bio-augmentation injections have been completed at this site (August 2011, April 2012, and January 2013).
January 2013 injection: 100 gallons of a solution Cl-Out was injected into the shallow groundwater zone through seven temporary injection points located accross accessible areas of the existing PCLE zone. The injection points were advanced using direct push methods on a grid approximately 20 feet. The target injection depth was between 35 and 40 feet below ground surface.

Results to date:
The analytical results of the most recent groundwater monitoring event indicate that stable to decreasing concentrations are present across the site except for a single monitoring well where concetrations continue to fluctuate. Currently, the highest concentration of PCE was reported in MW-13 at a level of )0.108 mg/L. The most current analytical data confirms that only a small portion of the original groundwater plume remains at the site.

Next Steps:
Continued monitoring of the ongoing groundwater response action at the site. Future monitoring and sampling of the groundwater plume will evaluate the effectiveness of the response action and determine if further action is needed.

Cost to Design and Implement:


Cost for Assessment:
Cost for Operation and Maintenance:
Total Costs for Cleanup:

Lessons Learned

Learned how bioremediation is cleaning up the site and the processes. I would evaluate how much Cl-Out has been used and see if less can be used to be as effective and reduce costs.


David Cullen
Project Manager
Texas Commission on Environmental Quality
PST/DCRP Section, Remediation Division, MC-137
P.O. Box 13087
Austin, TX 78711-3087

Site Specific References

Field Activities Report 2013
Affected Property Assessment Report 2009


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