New Hampshire businesses that used toxic chemicals in the manufacturing of Teflon and firefighting foams could face enforcement action under a pair of bills headed to the governor’s desk.

Gov. Chris Sununu (R)—a former environmental engineer—vowed to sign the bills, which would set new standards on how much of the chemicals can contaminate air and water.

The bills come after widespread contamination in Southern New Hampshire with perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and related compounds, which were linked to past releases by a plant now owned by Saint-Gobain Performance Plastics.

Under the legislation, if tests of...