The presence of the chemicals, known as perfluorinated compounds, or PFCs, prompted the shutdown of Martinsburg’s Big Springs water-filtration plant in May 2015 after the city was alerted to tighter federal guidelines for human exposure to the compounds.

The chemicals have been linked to cancer, liver damage and birth defects in recent scientific studies, according to the Environmental Protection Agency, which issued new lifetime exposure health advisories for the chemicals.

The 167th Airlift Wing was among the first group of Air National Guard bases in the country to have been investigated for the possible release of the chemicals as part of a firefighting effort or training, the U.S. Air Force said last year.

The Air Force identified potential locations where “aqueous film-forming foam” might have been released, including a former fire-training area, three hangars, two buildings, a firetruck-testing area, two storage areas and a wastewater-treatment area.

McCoy said the Air National Guard was notified in August by the West Virginia Department of Environmental Protection that the chemicals showing up in the Big Springs well had flowed through groundwater from the 167th Airlift Wing at Eastern West Virginia Regional Airport.

“We have agreed that we are a contributor to the PFC contamination and we are probably the only contributor,” McCoy said.

The airport is in the Big Springs wellhead-protection area for the city’s water supply.

An agreement between the city and the government providing for reimbursement of costs that Martinsburg already has incurred due to the water-contamination issue, as well as future costs, is expected to be finalized in the next couple of months, McCoy said.

That includes $94,567 that the city council voted Thursday night to pay the O’Brien & Gere engineering firm for interim services to restore water production at the Big Springs plant later this year.

City Manager Mark Baldwin said the city has already spent about $200,000 in response to the contamination issue and that also would be reimbursed.

McCoy estimated the initial five-year agreement to construct and operate a yet-to-be-installed carbon-filtration water system to treat the contaminated water could be $9.5 million to $10 million.

After the initial agreement expires, McCoy said the city would be reimbursed for the cost to maintain the specialized treatment system as part of a new five-year agreement.

He estimated the annual maintenance cost going forward would be about $1 million.

“The Air Force, the Department of Defense is fully committed to helping communities impacted by this chemical,” McCoy said.

Mayor George Karos thanked McCoy and others involved for taking part in “a team effort” to address the quality-of-life issue on behalf of city residents.

The contamination at the plant off U.S. 11 has led the city to heavily rely on its second major source of water at Kilmer Springs near War Memorial Park.