An Act relative to further testing after a CSO event

This bill requires the Massachusetts Department of Environmental Protection to conduct water quality testing following combined sewage overflow events, which occur when wastewater treatment systems discharge untreated sewage into waterways. The legislation mandates that testing be performed at multiple downstream locations using specific quality assurance standards, with the option to suspend testing during winter months based on weather conditions. Additionally, the department must compile annual reports to create predictive models for water quality and identify areas with high bacteria levels. Facilities found to have excessive bacteria content will be required to develop mitigation plans and may receive priority for state stormwater funding if they implement approved solutions.