CHEYENNE, Wyo. (AP) — The Army Corps of Engineers says it has pinpointed the major source of a cancer-causing chemical at a former nuclear missile site near Cheyenne.

The Wyoming Tribune Eagle reports the 1960s-era site is one of several local former F.E. Warren AFB launch sites where investigators have found trichloroethylene, or TCE, which was used to clean missile launchers. Officials consider recent test results showing the single biggest concentration of TCE ever discovered at the site a breakthrough.

The Restoration Advisory Board, which has been working with the Corps to treat the site's contaminated groundwater, met Thursday to discuss the preliminary test results from wells dug this summer.

Project geologist Jean Chytil says the discovery will help facilitate the cleanup of the contamination.

She says further testing is being conducted.