Annual Compliance Report

The federal Safe Drinking Water Act amendments of 1996 require that states submit an Annual Compliance Report to EPA by July 1 of each year presenting summary data on drinking water rule violations for the prior calendar year.

States must 1) prepare the annual report, 2) make the annual report available to the general public, 3) publish and distribute summaries of the annual report, and 4) submit the annual report to US EPA.

Oregon has 2,500 public water systems statewide that are subject to the federal safe drinking water requirements. These include cities, water districts, manufactured housing communities, schools, parks, and campgrounds. The 52 largest municipal water systems serve 80% of the population, yet 85% of the total number of water systems serve fewer than 500 people each. Federal regulations address 91 different drinking water contaminants. For most regulated contaminants, there is a Maximum Contaminant Level (MCL) established by EPA for that contaminant and an associated monitoring requirement.

For a few of the regulated contaminants, EPA established Treatment Technique requirements instead of MCLs. Oregon water systems must monitor for these contaminants on specific schedules or monitoring periods that vary from monthly to every 9 years and must demonstrate that the level of contaminants in the drinking water they supply is lower than the MCLs. The water systems engage private laboratories accredited by the OHA to analyze their drinking water samples, and the water supplier must report the results of their required samples to OHA. Oregon water systems submit 150,000 or more compliance sample results to OHA each year.

The 2020 Oregon Annual Compliance Report summary table shown below presents violation data for key contaminant groups that have MCLs. "Water Quality Violation" means that the drinking water at a water system exceeded the MCL or did not properly treat the water (Treatment Technique) for a specific monitoring period. "Monitoring violation" means that sample results were not received at all or not received on time from a water supplier as required for a specific monitoring period. For each type of violation, the total number of individual violations is listed, along with the total number of water systems that committed those violations. For detailed and current information on the drinking water quality at specific public water systems, see Drinking Water Data Online.

Most Oregon public water systems test their drinking water as required, submit the results on time, and demonstrate that their drinking water meets the maximum contaminant levels. We continue to work with all water suppliers to assure that drinking water quality problems are identified and corrected to protect public health.