Monroe, City of
Community water system in Benton County, Oregon, serving 723 people from surface water. 5 rules violated in the past three years, 1 still unresolved. Owned by local government.
Quarterly compliance history
2023
2024
2024
2024
2024
2025
2025
2025
2025
2026
2026
2026
2026
Still in violation
EPA data updated Oct 7, 2026
Consumer Confidence Rule (CCR)
Community water systems must deliver an annual water quality report (Consumer Confidence Report) to all customers by July 1, covering the previous year.
Consumer Confidence Rule (CCR)
Community water systems must deliver an annual water quality report (Consumer Confidence Report) to all customers by July 1, covering the previous year.
What it means: Community water systems must deliver an annual water quality report (Consumer Confidence Report) to all customers by July 1, covering the previous year. It must list all detected contaminants, compare them to MCLs, identify source water, and include educational language about lead. A violation means the report was not delivered on time or was incomplete.
Health effects: No direct health risk — this is an administrative transparency obligation. Failure means customers lack information to make informed decisions (e.g., whether to use bottled water for infants when lead is elevated).
Limit: No MCL — this is a reporting requirement
About this rule
TTHM (Total Trihalomethanes)
TTHMs are four compounds — chloroform, bromodichloromethane, dibromochloromethane, bromoform — formed when chlorine reacts with organic matter in water.
TTHM (Total Trihalomethanes)
TTHMs are four compounds — chloroform, bromodichloromethane, dibromochloromethane, bromoform — formed when chlorine reacts with organic matter in water.
What it means: TTHMs are four compounds — chloroform, bromodichloromethane, dibromochloromethane, bromoform — formed when chlorine reacts with organic matter in water. They are among the most common disinfection byproducts and form more readily in surface water systems with high organic loads.
Health effects: Long-term exposure is associated with increased bladder cancer risk. Some studies link high TTHM exposure to adverse reproductive outcomes. Bromodichloromethane is classified as a possible human carcinogen.
Limit: 0.080 mg/L (80 ppb) locational running annual average (LRAA)
About this contaminantAlso violated in the past three years
Oct to Dec 2023 to Oct to Dec 2026
Surface Water Treatment Rule (SWTR)
All systems using surface water (rivers, lakes, reservoirs) or groundwater under surface influence (GWUDI) must filter and disinfect.
Surface Water Treatment Rule (SWTR)
All systems using surface water (rivers, lakes, reservoirs) or groundwater under surface influence (GWUDI) must filter and disinfect.
What it means: All systems using surface water (rivers, lakes, reservoirs) or groundwater under surface influence (GWUDI) must filter and disinfect. Treatment technique violations mean the system failed to maintain adequate disinfectant residual, exceeded turbidity limits, or lacked required permits. Snowmelt and storm events can raise turbidity and pathogen loads in surface water.
Health effects: Without proper filtration/disinfection: Giardia lamblia (severe diarrhea, cramping), Cryptosporidium (life-threatening for immunocompromised individuals), viruses (hepatitis A, norovirus). Turbidity itself is not a health risk but can shield pathogens from disinfection.
Limit: Treatment technique: turbidity ≤0.3 NTU in 95% of monthly samples; detectable disinfectant residual in 95% of distribution samples
About this rule
Total Haloacetic Acids (HAA5)
HAA5 are five haloacetic acids formed when chlorine disinfectants react with naturally occurring organic matter in source water.
Total Haloacetic Acids (HAA5)
HAA5 are five haloacetic acids formed when chlorine disinfectants react with naturally occurring organic matter in source water.
What it means: HAA5 are five haloacetic acids formed when chlorine disinfectants react with naturally occurring organic matter in source water. Higher levels occur with more organic-rich source water or when water sits longer in distribution pipes. The violation indicates the locational running annual average exceeded the MCL.
Health effects: Dichloroacetic acid is a probable human carcinogen (Group B2). Long-term exposure to trichloroacetic acid may also increase cancer risk. Animal studies show liver, kidney, and reproductive effects at high doses.
Limit: 0.060 mg/L (60 ppb) locational running annual average (LRAA)
About this contaminantAbout this data
EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several in the same period. Unresolved means still in violation at EPA's latest data refresh. Measured contaminant levels are not part of this record; each system publishes them in its annual Consumer Confidence Report.
Service area from EPA's Public Water System Service Area Boundaries dataset: Random Forest method, Federal agency. The system's location is the centre of the service area EPA publishes for the system.
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 Oregon 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. Retrieved from ECHO on Oct 11, 2026.