MO SB1666

Creates "The Drinking Water Transparency and Accountability Act" requiring the Missouri Department of Natural Resources to establish a letter grade system (A, B, C, D, or F) for community water systems serving at least 15 connections and 25 residents

Grades will be based on violations of federal and state drinking water laws, financial sustainability, operation and maintenance history, and infrastructure violations, with a tiered point deduction system (1 violation = 1 point for systems under 50,000 customers; 5 violations = 1 point for larger systems)

Systems receiving a "D" or "F" grade may face administrative penalties, mandatory auditor oversight of funding, and restrictions on incurring debt unrelated to water system improvements

Local governments operating water systems graded "D" or "F" are prohibited from spending water system revenue on anything other than system improvements, with violations potentially resulting in court-appointed receivers or mandatory water purchase from another system

First letter grades must be published by January 1, 2028, and systems must include grades on consumer confidence reports; systems receiving federal infrastructure funds must submit detailed spending plans to the department