(CBS NEWS) -- Some 60,000 Wilmington, N.C., residents get their drinking water from the Cape Fear River.

DuPont and its spinoff company Chemours manufacture chemicals at a plant upstream from the city.

The plant is situated on a 2,100-acre property on the Cape Fear River in Fayetteville. It is there where a chemical called GenX -- a potentially cancer-causing substance that is a byproduct of DuPont and Chemours' manufacturing processes -- is produced.

Wilmington residents are demanding to know if those toxic chemicals are making their way downriver into the city's drinking water.

The Cape Fear Public Utility Authority co-authored a three-year study on the chemical's elevated presence in the water. But as CBS News' Jericka Duncan reports, the findings were never made available to the general public -- not even to Wilmington Mayor Bill Saffo.

Saffo met with Chemours officials, and couldn't believe what he heard: "We were alarmed. And we want to know how long that compound or that chemical had been dispersed into the Cape Fear River. And they told us since 1980."

Last week, a city council meeting in Wilmington was over capacity, as neighbors demanded their leaders hold Chemours accountable.

"Why has this been allowed to go on for so long?" asked one citizen, Kalli Smith. "I have been drinking this water my entire life."

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