The NH Supreme Court heard oral arguments Nov. 15 in a long-running case focused on contamination from PFAS chemicals emitted by manufacturing company Saint-Gobain.

The case is a proposed class action suit for residents exposed to PFAS contamination near Saint-Gobain’s Merrimack facility. Residents who say they’ve been exposed to toxic chemicals that contaminated their water are hoping the company will pay for medical monitoring for illnesses related to PFAS exposure, like certain cancers.

The case has been moving through New Hampshire courts since 2016. But courts in the United States have been split on the issue of medical monitoring, so New Hampshire’s Supreme Court is being asked to weigh in on whether the state recognizes claims for medical monitoring as a remedy for people who were exposed to toxic substances.

They have also been asked to address whether those people must prove they have a present injury from the toxins, or if they can seek medical monitoring without a present injury.

In a brief filed ahead of the oral arguments, lawyers for the plaintiffs also argued that the exposure to toxins and the increased risk of illness that creates a medically necessary need for testing is itself an injury, eligible for compensation.

Bruce Felmly, a lawyer for Saint-Gobain, argued that allowing claims for medical monitoring without a present physical injury would deviate from 200 years of common law in New Hampshire.