Report: Well pollutants not linked
Groundwater contamination near a former anti-aircraft missile site in the Deep Creek area appears to have come from at least two different activities, according to a hydrogeologic report prepared for the Environmental Protection Agency.
The report by Ecology and Environment Inc., which was released by the EPA on Wednesday, said the limited extent of trichloroethylene contamination in the area “suggests the TCE source is unrelated” to the source of two other chemicals commonly associated with rocket fuel.
Since discovering TCE in a well on Euclid Road in October 2004, the EPA has found the toxic solvent in six private wells and four monitoring wells in a study area around two sites that were once the Fairchild Defense Nike Battery 87.
In addition, perchlorate, a salt used in rocket fuel, has been found at low levels in 60 private wells and four monitoring wells. N-nitrosodimethylamine, a rocket fuel igniter known as NDMA, has been found in 33 private wells in the area west of Deep Creek and north of U.S. Highway 2.
EPA emergency response team coordinator Calvin Terada said the contractor’s finding means the TCE was not “dumped together” with the perchlorate and NDMA. Where the three chemicals came from has not been determined, but the EPA still considers the missile battery a “plausible” source of contamination.
The military once commonly used TCE to degrease engine parts, for example. Perchlorate and NDMA have been found together at sites where rocket fuel was stored or manufactured in Colorado and California.
The U.S. Army Corps of Engineers maintains that there is no conclusive evidence that the contamination came from past Department of Defense activity.
Also Wednesday, the EPA released a redacted report prepared by its Investigation and Engineering Unit in March, which explained the attempt to identify a source of the contamination.
During the “potentially responsible party search,” an EPA investigator interviewed longtime landowners in the area and Spokane County officials and researched military archives in an unsuccessful attempt to learn if any past chemical spills had occurred.
Both reports are available on the EPA Region 10 Web site.