Stage 2 Disinfectants and Disinfection Byproducts Rule in drinking water
100 active public water systems in 12 states had a Stage 2 Disinfectants and Disinfection Byproducts Rule violation in the past three years, and 100 had one in the latest quarter of EPA's data.
You are on Tapcensus, an independent guide to the EPA compliance records of every public water system in the United States. This page explains Stage 2 Disinfectants and Disinfection Byproducts Rule and lists the water systems whose records include a related violation. It does not show measured levels.
Is Stage 2 Disinfectants and Disinfection Byproducts Rule in the records for your water system?
Enter a ZIP code, town, or street address to see the water systems that serve your area, their status, and which rules and contaminants appear in their violations.
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What it is and where it comes from
The Stage 2 DBPR, effective 2006, tightened compliance requirements for TTHMs and HAA5 by shifting from system-wide averages to a locational running annual average (LRAA), ensuring high-exposure locations are not masked by low readings elsewhere. It applies to all community and non-transient non-community water systems that disinfect.
Health effects
The rule addresses long-term cancer risk and potential reproductive effects from disinfection byproducts, particularly trihalomethanes and haloacetic acids. Violations indicate that customers at the highest-exposure locations within the distribution system exceeded the byproduct limits, which poses greater risk than system-average exceedances.
The standard and what a violation means
EPA limit: TTHM LRAA: 0.080 mg/L (80 ppb); HAA5 LRAA: 0.060 mg/L (60 ppb).
Water systems with a Stage 2 Disinfectants and Disinfection Byproducts Rule violation, by state
Active public water systems that reported at least one related violation to EPA in the past three years. Each state links to the list of its affected systems.
| State | Systems with violations, 3 yr | Share of active systems | In violation, latest quarter |
|---|---|---|---|
| Florida | 45 | 1% | 45 |
| New Mexico | 15 | 1% | 15 |
| Arizona | 14 | 1% | 14 |
| Colorado | 7 | 0% | 7 |
| Louisiana | 6 | 0% | 6 |
| North Carolina | 3 | 0% | 3 |
| New York | 3 | 0% | 3 |
| Maryland | 2 | 0% | 2 |
| Tennessee | 2 | 0% | 2 |
| Missouri | 1 | 0% | 1 |
| Pennsylvania | 1 | 0% | 1 |
| Vermont | 1 | 0% | 1 |
Largest water systems with a Stage 2 Disinfectants and Disinfection Byproducts Rule violation
The ten biggest systems, by people served, whose records include a related violation in the past three years.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Ocud/western Regional Wtr Sys (5 Wps) Orlando · Orange County |
206,742 | 2 | 1 | |
|
Homestead, City of Homestead · Miami-Dade County |
80,000 | 4 | 1 | |
|
Winter Garden Water Dept (3 Wps) Winter Garden · Orange County |
72,205 | 2 | 2 | |
|
Davie, Town Of, #3 ; #5 Davie/hollywood · Broward County |
26,000 | 5 | 2 | |
|
Callaway, City of Water System Callaway · Bay County |
20,520 | 1 | 1 | |
|
Gulf Breeze Regional Water System Gulf Breeze · Santa Rosa County |
17,596 | 1 | 1 | |
|
Farmington Rural-Shiprock-Beclabito Ntua Upper Fruitland, Nenahnezad, San Juan and 1 more · County |
15,233 | 3 | 2 | |
|
Oldsmar Water System Oldsmar · Pinellas County |
14,898 | 3 | 2 | |
|
Gateway Services District Fort Myers · Lee County |
14,553 | 1 | 1 | |
|
City of Palmetto Water Dept. Palmetto · Manatee County |
13,446 | 4 | 2 |
About this data
A system is counted once if any of its violations in the past three years involved Stage 2 Disinfectants and Disinfection Byproducts Rule, including monitoring and reporting lapses. Rules violated and status in the systems table are for the whole system, not Stage 2 Disinfectants and Disinfection Byproducts Rule alone. Counts cover active systems in all 50 states and the District of Columbia.
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 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.