circle court ground water plume

117 CIRCLE COURT

The Circle Court Ground Water Plume Site is a trichloroethene (TCE) ground water plume in the Paluxy aquifer, parts of which are within the City of Willow Park and the City of Hudson Oaks, in Parker County, Texas. The source of the TCE in ground water has not been determined. The TCE contamination is present south o f Interstate 20 along a one - half mile section of Russell Road. The highest concentration exceeding the Safe Drinking Water Act maximum contaminant level (MCL) is present at Circle Drive and Russell Road. The plume boundary in the first figure below is estimated by the detection of TCE in water samples collected from private and public water supply wells. The ground water samples are from the shallow aquifer at an approximate depth of 100 to 250 feet deep. The site boundaries are not defined since the full extent and nature of contamination has not been investigated. The City of Willow Park and the City of Hudson Oaks supply water to most homes within the area of the site, except for some of the homes in the area of Russell Road. The ground water contamination was first detected in a public water supply well (designated as GW - 05 in the figure below) at a City of Willow Park pump station located at 117 Circle Court (see figure below). Single - family properties border the pump station to the south, west and east. A 15 - acre vacant wooded lot borders the pump station to the north. The combined March and June 2010 sampling events conducted by the Texas Commission on Environmental Quality (TCEQ) resulted in seven wells with documented levels of TCE. Three wells us ed for drinking water had TCE concentrations exceeding the maximum contaminant level of 5 micrograms per liter (μg/L) for drinking water. The highest level of TCE was found in a private domestic drinking water well located at 405 Russell Road, Willow Park (designated GW - 41). One non - drinking water well, located at the Parker County Airport was also documented to have a TCE level exceeding the MCL. The location of the TCE plume in the Paluxy aquifer approximately follows a one half mile stretch of Russell Ro ad, with one detection of TCE further to the east. TCE was first detected in March 2006 during routine monitoring of the City of Willow Park PWS at a concentration of 6.03 micrograms per liter (μg/L). The detection exceeded the EPA maximum contaminant le vel (MCL) for drinking water of 5 μg/L. The water sample that exceeded the MCL had been collected from the distribution system point of entry for the City of Willow Park well #20. As a result of the TCE exceedance in well #20, the well was taken out of service on April 1, 2006. On June 19, 2006, the City of Willow Park installed granular activated carbon filters on the impacted well, and the well was subsequently put back into service. The Circle Court Site was listed as final on the National Priorities List in September 2012, and EPA began the Remedial Investigation. A drum labeled with TCE as a product and still containing residual concentrations of TCE was located in close proximity to a private water supply well containing the highest TCE concentration at the Site. The initial field activities were completed in November 2012 and included the geophysical logging of selected private water supply wells and the collection of passive soil gas data around the site of the TCE drum located on Russell Road, near the site center. The passive soil gas data was delivered in December 2012 but the data did not identify a spill or disposal of TCE on the property surrounding the drum location. The geophysical logging provided information on the Paluxy aquifer and possible pathways for the migration of TCE in ground water. The response actions to date have been to ensure that the residents affected have safe water to drink. All of the residences with private wells that have TCE concentrations exceeding the drinking water standard of 5 micrograms per liter have now been connected to the public water supply system or have installed and maintained their own filtration system.