The Environmental Protection Agency (EPA) is planning to tighten standards for four water contaminants that can cause cancer as part of a new strategy to toughen drinking-water regulation. EPA said it will start rulemakings to revise standards for two contaminants used in industrial or textile processing, tetracholorethylene and trichloroethylene, within the year. The EPA will follow that rulemaking by setting stricter standards for epichlorohydrin and acrylamide, which can contaminate drinking water through the water-treatment process.

This week, President Obama announced $8.3 billion in federal…