Requires water supply system testing and compliance with secondary drinking water regulations.

This bill requires public community water systems (like municipal water utilities) to test water quality quarterly for secondary drinking water standards, including sampling from at least 10% of customer taps. It mandates that water system operators submit test results to the state environmental agency, local municipalities, and customers annually and quarterly. If tests exceed standards, operators must create a compliance plan within 30 days to fix issues within 30 days (or sooner if needed for health risks), followed by a maintenance plan to prevent future violations. These rules aim to ensure ongoing water quality for communities served by public water systems.