Potatoes blossom in a field on the Centerline Road in Presque Isle in July 2020. Credit: Paula Brewer / Star-Herald

PRESQUE ISLE, Maine — As evidence of “forever chemicals” contamination in Maine grows, so does concern about the state’s crops and whether they are safe to eat.

The greatest PFAS — per- and polyfluoroalkyl substances —levels tested so far have been f ound at dairy farms in southern and  central areas, causing some farmers to shut down temporarily or even permanently. Fish have also been affected. PFAS enter farm products through the spreading of wastewater sludge and septage, but they can enter the food chain indirectly through some household products and food packaging, among other sources.

Maine’s three top crops are potatoes, milk and blueberries. In potato-centric Aroostook County, the burning question is whether these “forever chemicals” have made their way into the No. 1 crop. The answer is no one is certain yet, but experts say while other types of foods produced in Maine such as dairy and beef are clearly vulnerable, potatoes may be a crop that sees a lower impact.

“Initial test results on potatoes demonstrate very low to no takeup of the chemicals into the plant,” said Nancy McBrady, director of the Bureau of Agriculture, Food and Rural Resources of the Maine Department of Agriculture, Conservation and Forestry. “Early indications are encouraging.”

Though state experts aren’t working with potato producers right now, so far there isn’t a concern about spuds for a couple of reasons, McBrady said.

First of all, state and federal guidelines on sludge application are more restrictive on land used to grow food. It’s therefore less likely for sludge to have been applied on food crop acreage to begin with. Secondly, a lot of agricultural commodities are grown in rural, less populated locations where there aren’t a lot of biosolids to spread, she said.

Science plays a role as well. Sludge years ago was stabilized with lime, which raises soil pH and could have led to concerns about potato scab, McBrady said. Growers would have shied away from spreading sludge on their farmland.

The testing process began only recently, and gathering data on Maine’s many farms and crop varieties will take time, McBrady said.

But people shouldn’t rush to judgment when a farm is identified with PFAS contamination, she said. State investigators are forging new territory in finding what levels are safe, which is a slow, deliberate process. Farmers who might have had some sludge spread on part of their land aren’t necessarily growing unsafe products.

In October, the state passed An Act to Investigate Perfluoroalkyl and Polyfluoroalkyl Substance Contamination of Land and Groundwater, requiring the Maine Department of Environmental Protection to test soil and groundwater at all sites that were allowed to apply wastewater sludge before 2019.

Since testing has only recently begun, there’s a long way to go to collect data and understand the scope of the PFAS problem and potential remedies, McBrady said. The DEP has until 2025 to test locations with confirmed sludge and septage spreading.

There is financial help when farms test positive, she said. The Department of Agriculture will underwrite costs for the extensive sampling and investigation, along with ongoing testing to make sure the remediation efforts are working.

“That’s no longer something farms will need to worry about,” McBrady said.  

The department can also pay for water filtration systems, if necessary, for farming water, and is crafting a process to offer replacement income for farms unable to sell products due to PFAS contamination.

The Maine Association of Organic Farmers and Gardeners and the Maine Farmland Trust will also offer aid.

Right now, Fairfield is the area where the highest PFAS concentration has been identified in drinking water, said DEP Deputy Commissioner David Madore. DEP began testing in November and will concentrate first on sampling Tier 1 sites, where more than 10,000 cubic yards of sludge and septage were applied.

The Presque Isle Utilities District’s former wastewater lagoons sat off the Lathrop Road in Presque Isle. Since 2020, alerted by DEP about unacceptable PFAS levels, the district stopped using the lagoons and now processes sewage sludge by dewatering and taking it to the landfill. Credit: Anthony Brino / BDN

“Our goal is to ensure that safe drinking water below Maine’s Interim Drinking Water Standard is provided,” he said.

Due to the frozen ground, DEP has only sampled drinking water in Aroostook County so far. Soil sampling will be scheduled later, he said.

In November, the  DEP identified 34 towns as Tier 1 sites. Houlton, Littleton and Presque Isle are the Aroostook County communities on that list.

Until 2020, Presque Isle spread sludge on non-agricultural fields off the Chapman Road. But after the DEP confirmed PFAS contamination in some nearby wells and groundwater, the district halted spreading.

“Food crops were not grown on the fields where sludge was applied,” said Presque Isle Utilities District Superintendent Ross McQuade.

Presque Isle began a $15.6 million update of its Dyer Street treatment plant to enable it to dry out, or dewater, the sludge and dump it at the landfill, rather than spreading it on land in April 2021. A dewatering centrifuge was installed and a building constructed to house the equipment and all sludge is now deposited at the landfill, McQuade said.

Staff at the Presque Isle DEP office will have a busy spring and summer, said Northern Regional Director Bill Sheehan. When the ground thaws, they plan to test about 30-50 Aroostook County locations, including some septic sites and all places where wastewater treatment plants had spread sludge.

Time and extensive study will tell what crops, even if planted on PFAS-containing soil, will be safer to grow. No one can paint a wide brush with PFAS because it’s specific for every farm involved and what is being grown there, McBrady said.

“Going back to the potato, perhaps even with soil with some amount of PFAS, you can grow a safe potato.”