AUGUSTA, Maine (AP) Wastewater treatment plants across Maine are working quickly to meet a deadline to begin testing municipal sludge for so-called forever chemicals.

The testing deadline imposed by Democratic Gov. Janet Mills’ administration reflects a growing nationwide concern over the class of chemicals known as PFAS. The Portland Press Herald reports water treatment facilities must now meet an April 12 deadline for filing plans for testing sludge intended to be used as fertilizer.

The Maine Department of Environmental Protection has also set an initial testing deadline of May 7.

PFAS have been linked to cancer, thyroid disruption, low birth weights and other potential hazards to health. Mills recently announced the creation of a task force to study PFAS contamination in Maine.