Chapter 6 – Safe Drinking Water Act: Once Seen as a Problem Solved, But Now New Worries


The Safe Drinking Water Act (SDWA) requires EPA to develop health-based standards for a list of potentially toxic contaminants found in water supplies, including micro-organisms, inorganic chemicals (including lead), organic chemicals, radionuclides, disinfectants, and disinfection byproducts. EPA establishes National Primary Drinking Water Regulations (NPDWRs) based on Maximum Contaminant Level Goals (MCLGs) or public health-based goals. EPA also sets Maximum Contaminant Levels (MCLs) that define actual exposure levels using a risk balancing approach that considers technology limits, costs, and health risk reduction. SDWA requires information disclosure by drinking water systems of water quality and standard violations in an annual Consumer Confidence Report. It also regulates underground injection wells. The SDWA has its shortcomings. Notably, it does not apply to private wells or new unlisted contaminants (such as PFAS), and some states have been lax in enforcing the rules. Lead contamination of drinking water in Flint, Michigan exemplifies such failures.