The building located at 5800 E. Jewell Ave. originally was built in 1956 and 1957 by a company that used the facility to manufacture measuring instruments and electrical devices. From that time through 1998, the property housed manufacturing operations. Various companies using the Redfield name manufactured gun scopes and similar items at this site from 1967 until 1998.* Brown Group Retail, Inc. currently owns the property, including the building, and is managing the cleanup of solvents in groundwater both beneath the site as well as groundwater that has flowed into adjacent neighborhoods.
Since 1994, when groundwater contamination associated with the site was first discovered, Brown Retail has worked with the Colorado Department of Public Health and Environment (CDPHE) to assess the extent of groundwater contamination and to determine whether solvent vapors, particularly from the chemical 1,1-DCE, have migrated from groundwater through the soil and into residential foundations in homes near the site.
Indoor air testing involves placing a canister in the lowest level of homes for 24 hours, then sending it to a laboratory for analysis. In homes that test above the State�s action level for 1,1-DCE, the level at which CDPHE requires cleanup action to occur, Brown Retail has installed ventilation systems identical to those used to solve radon problems.
In addition, Brown Retail installed a groundwater containment and treatment system on the property that began operating in March 2000. The system intercepts groundwater exiting the site and cleans it before it flows from beneath the site and into the surrounding area to the north and east of the site.
Groundwater-monitoring wells, which allow scientists to analyze the concentrations of chemicals in the groundwater, have been installed throughout the areas north and east of the Redfield site. The data collected from these wells, in addition to the indoor air testing results, help further delineate where the affected groundwater is located.
These tests have enabled Brown Retail and CDPHE to delineate boundaries of impacted groundwater flowing off of the Redfield site. To date, the extent of the groundwater contamination has been defined on the south, east and west sides of the plume. Cherry Creek is the boundary to the north, and testing reveals no impact to the Creek or to groundwater north of the Creek. Brown Retail is in the process of testing apartments on the northwest portion of the plume. The apartments are located on Cherry Creek Drive South, north of Mississippi Avenue. This testing should reveal the total horizontal extent of the affected groundwater and/or indoor air to the northwest.
On October 1, 2002, Brown Retail submitted a remediation work plan to CDPHE for addressing contaminants in the off-site groundwater. The plan proposes two new cleanup actions: 1) enhanced injection of water currently being cleaned by the groundwater treatment system along the northeast portion of the Redfield property, and 2) installation of an underground "bioremediation" system where the bedrock channel and the groundwater plume cross S. Jasmine Street, south of E. Mexico Avenue. The enhanced injection system includes the installation of eight new treated-water injection wells. These new wells will allow Brown Retail to inject more clean water into the ground, which in turn, will accelerate the flushing of residual solvents from the aquifer. Each time the aquifer is flushed with clean water, more solvents are removed and concentrations decrease, until the solvent concentrations are at or below Colorado groundwater standards.
The bioremediation system at S. Jasmine Street will create an environment in which naturally occurring biological organisms can break down the solvents in the groundwater. The system will involve injecting oxygen, nutrients, and "food" into the groundwater using wells, so that these organisms can grow. As these organisms consume the food, they also break down the solvents. The Colorado Department of Transportation (CDOT) is using the same process to degrade similar compounds below homes and apartment buildings near its Materials Testing Laboratory facility in Glendale, and for solvents flowing onto the Redfield site from its Region 6 Headquarters facility.
By degrading the solvents as they pass through the bedrock channel at Jasmine Street, clean water will be created that will continue to flow down the channel. Additionally, some of the oxygen, nutrients and food injected into the treatment zone will travel with the groundwater, boosting the natural degradation processes. Therefore, while the enhanced injection system is cleaning the portion of the plume near the Redfield property, the underground bioremediation system at Jasmine Street will help flush clean water into the remainder of the plume and further accelerate the degradation of solvents to levels at or below Colorado�s groundwater standards.
Brown Retail is committed to identifying and addressing all homes that may be impacted by the groundwater. We invite you to read the material published here, and call or e-mail us if you have any questions or concerns. Updates on indoor air sampling, groundwater treatment and other environmental activities will be posted to the site as more information becomes available.
*The prior site history indicated incorrectly that Redfield Rifle Scopes, Inc. operated on the site between 1967 and 1998. Redfield Rifle Scopes, Inc., an Iowa corporation, only operated on the site between 1984 and 1998. Other entities using the Redfield name operated on the site between 1967 and 1984.
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