Drycleaner Site Profiles

USA Cleaners, Dallas, Texas

Description
Historical activity that resulted in contamination.

USA Cleaners occupies a lease space in a shopping center and the has been located on the subject property since 1971. Upon initial investigations, the saturated soil unit located a 5-11 feet bgs was thought to be the first groundwater bearing unit (GWBU) and was treated as groundwater. An ISCO interim response action was completed. The groundwater classification was re-evaluated in the ISCO Pilot Test Report (October 13, 2010). There were several indicators that the groundwater at the USA Cleaners site may be appropriately classified as saturated soils as opposed to a GWBU. Therefore this site treats the saturated soil unit as soil and not a GWBU.

Remediation Status: Site closed


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


Contaminant Media Concentration (ppb) Nondetect
cis-1,2-Dichloroethene soil 220 ppb
1,1-Dichloroethene soil 0.47 ppb
Tetrachloroethene (PCE) soil 11,000 ppb
Trichloroethene (TCE) soil 110 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:  
Plume Size:  
Average Depth to Groundwater:   970ft

Lithology and Subsurface Geology

 
  Saturated soils. The depth to water in saturated soil ranged from 5 to 11 feet bgs in the site assessment activities with a potentiometric gradient to the southwest that generally coincides with the topographic gradient
Depth: 0-30ft bgs
30ft thick
Austin Chalk and Eagle Ford Shale formations
  Shale bedrock. The saturated soil is underlain by chalk, marl, calcareous clay, and shale in the Austin Chalk and Eagle Ford Shale formations, and the uppermost GWBU is the Woodbine aquifer.
Depth: 27-30ft bgs
3ft thick

Pathways and DNAPL Presence

Groundwater
Sediments
checkSoil
DNAPL Present

Vapor Intrusion Pathway

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

Remediation Scenario

Cleanup Goals:
  Reduce COC levels below MCLs
Remedy Level:
  Interim Action

Technologies

In Situ Chemical Oxidation
 

Why the technology was selected:
ISCO was selected for remediation based on the presumption that the initial groundwater encountered at the site was a Class 3 resource.

Date implemented:
June 2010

Final remediation design:
12 temporary injection wells were installed to depths ranging from 19 to 26.5 ft BGS. The injection wells were constructed of 1-inch polyvinyl chloride (PVC) and had either 10 or 15 ft of 0.010-inch slot well screen, depending of well depth. The temporary injection wells were backfilled with
soil cuttings to approximately 2-ft BGS, and then grouted to the surface. The ISCO interim response action led to the injection of more than 2,500 pounds of sodium permanganate into the saturated soils beneath the asphalt parking lot behind the dry cleaners.

Results to date:
ISCO treatment increased the
concentrations of COCs in MW-1 because of the flushing of contaminated water towards the well, but reduced the concentrations of COCs in MW-2 and MW-9. The concentration of PCE increased from 7.2 to 11 mg/L in MW-1, but the concentrations of PCE dcreased from 3.1 to 1.6 mg/L in MW-9 and from 0.78 to 0.097 mg/L in MW-2. Although ISCO treatment is imcomplete, residual permangate was injected into the preferential flow paths in the saturated soils. Although permanganate is stable and retains a capacity for the oxidation migrating water, permanganate is reduced by the natural oxidant demand of the water.

Next Steps:
Because the concentrations of chlorinated VOCs are below the applicable PCLs for surface soil,
subsurface soil, and saturated soil, no further sampling or response actions are warranted.

Cost to Design and Implement:
$73,398.55

Costs

Cost for Assessment:
  $99,593.16
Cost for Operation and Maintenance:
 
Total Costs for Cleanup:
 

Contacts

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 2010
In-Situ Chemical Oxidation Pilot Test Report 2010
Affected Property Assessment Report 2011