The soil and grass at Stoneridge Farm in Arundel is contaminated with PFAS chemicals as are the cows and their milk, a result from sewage sludge spread on the farm fields between 1983 and 2004. The farmers’ plight shifted the focus of concern over the chemicals. Gregory Rec / Portland Press Herald

The Maine Department of Environmental Protection will continue its investigation into potential contamination of PFAS — or “forever chemicals” — in Bowdoinham through mid-January.

The DEP conducted the first field visit to Bowdoinham on Dec. 3, where staff tested soil and groundwater at several sites.

“Additional field visits are scheduled to take place in Bowdoinham the last week of December and the second week of January,” said Deputy Commissioner of Maine Department of Environmental Protection David Madore. “The focus will be on groundwater sampling. The DEP staff are in the process of contacting residents where sampling is planned to take place.”

In October, the state identified 34 communities, ranging from small rural towns like Bowdoinham to cities such as Westbrook, that would be tested first for PFAS contamination based on various risk factors.

The DEP reviewed decades of licenses and sludge application records to compile the list of 34 communities, according to the letter issued by the DEP to Bowdoinham.

While the state’s groundwater of per- and poly-fluoroalkyl substances, or PFAS concentration limit, is set at 400,000 parts per trillion, the established state drinking water standard is 20 nanograms per liter of water for the combined sum of six different PFAS.

According to Portland Press Herald analysis of DEP documents, at least eight paper companies spread more than 500,000 cubic yards of paper mill waste on land in Maine between 1989 and 2016, which is likely a conservative estimate because it does not include biosolids obtained from wastewater treatment plants that processed paper mill sludge and wastewater.

PFAS are used in products ranging from non-stick cookware to carpets, food packaging and firefighting foams. These chemicals can increase the risk of certain types of cancer, elevate blood pressure during pregnancy, can cause liver and kidney problems and can impair the immune system.

Madore said the DEP would use and maintain the data collected to determine the extent of PFAS contamination in Maine.

“As data is collected, the DEP’s hydrogeologists and geologists will be able to understand more about how PFAS move in the soil and groundwater,” said Madore. “This is important as it can help us ensure that all Maine residents have safe water to drink.”