Residents in this Hudson River city about 70 miles north of New York City had been drinking contaminated water for decades. Now many are grappling with ill health.

In 2016, the state traced the toxins to Stewart Air National Guard Base, where PFOS-laden foam had been used for firefighting and drills since the 1980s.

Stormwater from the base emptied into a stream that flowed into drinking water for 30,000 people.