Article originally featured in the Idaho Tribune March 15, 2008 Issue
Article featured in the March 15, 2008 issue of the Idaho Tribune.
A crew from Utah and a van of high-tech gadgets are making their way around Caldwell, probing deep beneath the earth to test for the dry-cleaning chemical perchloroethylene, or perc, and other hazardous compounds.
Funded by Environmental Protection Agency Brownfields grant money, the work is intended to make sure new development expected to comes as a result of the city’s downtown revitalization projects is safe, and harmful chemicals that may lie beneath the city do not spill into the usable water supply.
Former City Councilman Rick Wells said the results of the current probes will be combined with data taken in 2005 to create a fairly comprehensive 3-D image of underground chemical concentrations. The city hired Wells, owner of Spectrum Environmental, after he was replaced on the council by Bob Sobba to continue environmental work he had previously done without pay.
Lauren Steely, West Coast operations manager with Baltimore-based Columbia Technologies, traveled to Caldwell with the van from her company’s Los Angeles office. She explained that the probe driven into the ground collects samples through a thin membrane every few inches and feeds them to an array of detectors in the van.
The equipment is capable of detecting petroleum compounds as well as chlorinated compounds such as perc. Conductivity sensors also provide information on soil composition and where clay layers lie.
Wells and Redevelopment Coordinator Dennis Cannon said the data collected in 2005 prompted planners to raise the bottom of Indiana Creek’s new channel by a few feet, preserving the clay layer and preventing any potential perc contamination of the creek’s water.
Cannon said the work may help the city trace the source of any perc contamination, and will allow planners to take precautions when designing new buildings to prevent future issues.
The technology being used is relatively new. Wells learned of it at a national EPA conference he attended as a councilman, and its application by the city in 2005 is believe to be the first in the state. It is gaining popularity because it is much cheaper and more efficient than traditional testing methods.
Several communities across the state have expressed interest in the process, and have been invited to visit Caldwell as the tests continue.
The city is also working closely with the EPA and Idaho Department of Environmental Quality to analyze the data as it is collected, and Wells said probing will continue until the city and agencies are satisfied to avoid having to perform additional tests later at added cost.
Andrew Provant, a project geologist with Kleinfelder, said crews are probing eight sites in an average day. Kleinfelder is a professional services firm that contracts with Caldwell.
The process leaves a hole several inches in diameter, which workers fill and seal before moving on.
