Tapcensus

Stage 1 Disinfectants and DBP Rule violations in California

5 active public water systems in California had a Stage 1 Disinfectants and DBP Rule violation in the past three years, 5 of them in the latest quarter of EPA's data. What Stage 1 Disinfectants and DBP Rule is and why it matters.

Health effects: See TTHMs (2950) and HAA5 (2456) for their specific health effects. Bromate is a probable human carcinogen (Group B2). Chlorite at elevated levels can cause hemolytic anemia, particularly in infants, developing fetuses, and individuals with certain enzyme deficiencies. Violations indicate the system exceeded one or more of these byproduct or disinfectant limits.

Systems with a Stage 1 Disinfectants and DBP Rule violation

Latest quarter first, then largest first
SystemServesStatusRules violated, 3 yrUnresolved
Big Pine Paiute Band
Big Pine Reservation · County 		600 1 1
Grindstone Rancheria
County 		150 9 4
Round Valley Health Clinic
County 		119 7 3
Mescal Creek Water, INC
Los Angeles County 		80 2 2
Indian Village
County 		35 7 2
About this data

A system is counted once if any of its violations in the past three years involved Stage 1 Disinfectants and DBP Rule, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Stage 1 Disinfectants and DBP Rule alone.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The California records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.