Site Profiles - View. General Information. Contaminants: Site Name and Location: Description: Historical activity that resulted in contamination.

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1 Site Profiles - View General Information Site Name and Location: Description: Historical activity that resulted in contamination. Rummel Creek Shopping Center Houston, Texas, United States The facility is located in a mixed commercial/residential area comprised mainly of strip centers, restaurants, gas stations, and residential developments. A creek bounds the property on two sides. A dry cleaner operated at the site from and again from An active dry cleaner is located across the utility easement. This site has an extensive monitoring network of 19 wells and the groundwater contamination has impacted residential property. Contaminants: Contaminants: Contaminants present and the highest amount detected in both soil and groundwater (please avoid giving ranges). Other Contaminants Present: Indicates what other contaminants were found on-site Deepest Significant Groundwater Contamination: Plume Size: Contaminant 1,1-Dichloroethene cis-1,2-dichloroethene Tetrachloroethene (PCE) trans-1,2-dichloroethene Trichloroethene (TCE) Vinyl Chloride Conc in GW Conc. in Soil 9.7 µg/l 2600 µg/l 2200 µg/l 20 µg/l 610 µg/l 12 µg/l (1 of 5)2/2/2006 4:31:03 PM

2 Site Hydrology: Depth to Groundwater: Lithology and Subsurface Geology: Conductivity: Gradient: ft bgs The first saturated unit is located at approximately 20 ft. bgs. This unit is identified as a sandy to silty-sand zone terminating at approximately 33 ft. bgs. This unit is unconfined. measured from 4.2 to 9.2 ft/day ft/ft Media: Media: Groundwater Remediation Scenario: Cleanup Goals: Technologies: Technologies Used: PCE: 5 µg/l TCE: 5 µg/l cis 1,2-DCE: 70 µg/l Trans 1,2- DCE: 100 µg/l VC: 2 µg/l In Situ: Bioremediation Chemical Oxidation Soil Vapor Extraction Ex Situ: Removal Other technologies used: Why the technology was selected: Date implemented: In-situ chemical oxidation (ISCO) was selected because it can oxidize DNAPLs, does not require expensive pump systems, can treat area without disturbing aboveground structures, and does not require excavation and disposal of contaminated soils. Potassium permanganate was specifically selected because it has been shown to be effective for chlorinated solvents; it does not react with carbonate and bicarbonate in soil; the reaction is not exothermic; and the reaction is not toxic to microbes in the soil. 7/17/01 (2 of 5)2/2/2006 4:31:03 PM

3 Final remediation design: A % KMnO4 was injected into the perched water bearing zone, about ft bgs using direct push technologies. The remediation was completed in a phased approach. Injections occurred four times over a one year period. A total of 837 pounds of KMnO4 was injected, which is equivalent to 9485 gallons of solution. Each phase included both on-site and off-site injections. The infections on site were completed around the three identified source areas on the site at a spacing of ft. Off-site injections targeted the dissolved phase plume. Each injection point received injections at two depths: one approximately 5 ft from the bottom of the transmissive zone, and the other five to 10 ft above the first. The solution was injected at a rate of 1-5 gallons/minute, at a pressure of psi. In addition to the permanganate injections, enhanced bioremediation was also employed at three source areas using a biological product called Cl-Out, which consists of freeze dried strains of naturally occurring bacteria that provides rapid, aerobic degradation of chlorinated compounds. Dextrose is added to activate the bacteria. These bacteria were injected in Februaru 2003 using a series of temporary injection points. The injection points were spaced 6-25 ft apart. Soil impacts were addressed through excavation along the sanitary sewer line, one of the only parts of the site not covered with asphalt. This unpaved part of the property was accumulating storm water and therefore covered with an impermeable cap. Underneath this cap, an SVE system was installed. The system consisted of a gallery of 6 vertical, 2-inch-diameter PVC wells, 3 feet deep, and 10 feet apart. The areas around the system were filled with pea gravel. The SVE system was operated for 2 months to remove any residual soil contamination in the area. Results and Next Steps: Results to date: The highest pre-injection concentrations seen at the source wells were 2200 µg/l for PCE and 610 µg/l for TCE. Following the first KMnO4 injection, the concentrations in the source wells ranged from non-detect-79 µg/l for PCE and non-detect-74 µg/l for TCE. The TCE and PCE concentrations were noted to fluctuate across the non-source wells, but the concentrations were generally decreasing. At the downgradient wells, the plumes have remained stable, or had decreased. Following the Cl-Out injection in February, results in two source wells sampled in December 2003 showed PCE decreasing from 700 µg/l to 43 µg/l, and 130 µg/l to 26 µg/ (3 of 5)2/2/2006 4:31:03 PM

4 Next Steps: L. TCE in the two source wells decreased from 250 µg/l to 21 µg/l, and 140 µg/l to 8 µg/l. Monitoring will continue on a quarterly basis. The owner plans to apply for a conditional closure of the site. Costs: Cost for Assessment: Cost to Design and Implement: Cost for Operation and Maintenance: Total Costs for Cleanup: Lessons Learned: Lessons Learned: 1. Deep drainage ditch may have acted as a pathway for offsite contamination. Contacts: Principal Point of Contact: Dan Switek, Project Manager Texas Commission on Environmental Quality PO Box 13087, MC-136 Austin, TX Site Specific References: Site Specific References: Images: Consultant: InControl Technologies 3845 FM 1960 West, Suite 250 Houston, TX (4 of 5)2/2/2006 4:31:03 PM

5 Images of Site: Profile last updated on Jun 28, (5 of 5)2/2/2006 4:31:03 PM