Private well water to be tested in Cascade Valley

MOSES LAKE - The Army Corps of Engineers begins in May testing private drinking water wells for contaminants at Cascade Valley in Moses Lake.

The Seattle District Army Corps will go door-to-door asking for access to about 35 new private drinking water wells and wells previously tested in the past, according to a press release issued Friday. The testing is scheduled for May and is part of the Environmental Protection Agency's long-term effort to clean contaminated water and soil at the Moses Lake Wellfield Superfund site.

The majority of Moses Lake residents receive water from the city or community system, which is tested regularly to meet safety standards, but small water systems and private wells are not required to be tested, according to Corps' statement

In past years, all wells tested for trichloroethylene (TCE) in Cascade Valley have met safe drinking water standards but Dan Sacks, Corps project manager, wants to make sure this is still the case.

"We are sampling the monitoring wells this year to see if the groundwater plumes are moving, if conditions have changed and what types of contaminants are present," Sacks said. Groundwater contamination resulted from operations on the former Larson Air Force Base and Grant County Airport where TCE, an industrial solvent, was used for cleaning and stripping aviation parts. As a result, deep beneath the soil are two TCE-contaminated groundwater plumes located under the former base property. The two plumes begin under the base, spreading more than a mile south.

Last year, the EPA installed groundwater monitory and extraction wells to learn more about the plumes and how to clean it up. By 2014, installation of extractions wells will be completed and the groundwater treatment system in place to restore the groundwater as a drinking water source. Results from the well testing will be made available in September.