In this May 16, 2018 photo, Environmental Protection Agency Administrator Scott Pruitt appears before a Senate Appropriations subcommittee on the Interior, Environment, and Related Agencies on budget on Capitol Hill in Washington. Four Democratic senators are asking Pruitt for details about his new legal defense fund. (AP Photo/Andrew Harnik)

WASHINGTON | Environmental Protection Agency chief Scott Pruitt says dealing with a widespread contaminant in drinking water is a “national priority.”

Pruitt spoke Tuesday as he opened a hearing on the contaminants, known as perfluoroalkyl and polyfluoroalkyl. The chemicals were used in items like nonstick coating and firefighting foam and have contaminated some water systems nationwide. The compounds are linked to developmental defects and other health problems.

In this May 16, 2018 photo, Environmental Protection Agency Administrator Scott Pruitt appears before a Senate Appropriations subcommittee on the Interior, Environment, and Related Agencies on budget on Capitol Hill in Washington. Four Democratic senators are asking Pruitt for details about his new legal defense fund. (AP Photo/Andrew Harnik)

Pruitt has faced criticism in recent weeks over emails showing the EPA sought to intervene in a critical study on the contaminants.

Convening Tuesday’s session, Pruitt is pledging to work on establishing a maximum allowable level for the chemicals in drinking water.

Representatives of states, tribes, the chemical industry, environmental groups and others are attending the session.