MACHIASPORT – If all goes as the Army Corps of Engineers hopes, someone who once worked at two former radar sites in Bucks Harbor will come forward Wednesday to say where the U.S. Air Force disposed of chemicals that were used at the sites.

The radar tracking system on Miller and Howard mountains closed in 1984, and the corps, which is charged with the cleanup of former defense sites, is looking for the source of the trichloroethylene that was detected in 15 Machiasport wells in 1995.

If the areas where TCE entered the aquifer under the mountains can be identified, the corps may be able to track the path of the solvent through the fractured bedrock, according to David Margolis, the corps project manager for the Machiasport cleanup.

Last week, Margolis issued an invitation to people who worked at the sites from the 1950s through the early 1980s to come to the Machiasport town office from 9 a.m. to 1 p.m. Wednesday, Aug. 7.

Margolis said Friday that former employees may help “connect the dots” between Miller and Howard mountain sites and the wells.

“I’d suspect there are multiple small points where someone disposed of it,” he said. “We know TCE was used as a cleaning agent at facilities like these and that is was just dumped out back or in a dry well.”

Margolis said that using dry wells as disposal areas was common before anyone understood the potential for contaminating groundwater. Any information from former employees will be kept confidential and will not be used to hold someone liable for the contamination, he said.

Once the sites are identified, the consulting engineers for the project can use geophysical information and install test borings to determine the location of the bedrock fractures. That will help determine whether the TCE is pooled somewhere in the aquifer and dispersing from that location, he said.

The call for information from former employees is the first obvious step the corps has taken since February when the state Department of Environmental Protection rejected what it said were interim cleanup measures, such as continuing to supply water filters to the affected homeowners.

DEP has a memorandum of understanding with the corps on the cleanup of former defense sites in Maine, and the department said the only acceptable response to the Machiasport contamination is to provide a new water supply for affected residents or clean the TCE out of the aquifer.

If affected residents are to have a new water supply, DEP maintains that there must be a buffer area to contain any TCE that travels from the area around the affected wells.

Such a buffer zone would require deed restrictions or a town ordinance to ensure that current and future landowners didn’t drill wells within the buffer zone because that could result in the contamination moving, according to DEP.

Margolis said the corps intends to meet with DEP within the week after Wednesday’s public session and also will schedule a follow-up meeting with the Restoration Advisory Board, the group of community residents working with the federal and state agencies to oversee the cleanup.

Wednesday’s session with former employees may include visits to the sites, Margolis said.