Drinking Water Violations

Indicator of the presence of health-related drinking water violations. 'Yes' indicates the presence of a violation, 'No' indicates no violation.

The 2022 County Health Rankings used data from 2020 for this measure.

Reason for Ranking

Ensuring the safety of drinking water is important to prevent illness, birth defects, and death.[1] Other health problems have been associated with contaminated water, including nausea, lung and skin irritation, cancer, kidney, liver, and nervous system damage.[2,3] An increase in drinking water violations has also been shown to increase health care expenditures.[4] Between 3 and 10% of community water systems experience a violation each year.[5] 

Key Measure Methods

Drinking Water Violations is an indicator

Drinking Water Violations has only two values: Yes and No. A “Yes” indicates that at least one community water system in the county received at least one health-based violation during the specified time frame. A “No” indicates that there were no health-based drinking water violations in any community drinking water system in the county.

The method for calculating Drinking Water Violations has changed

In 2018, the County Health Rankings updated the data source to the Safe Drinking Water Information System Federal Reports Advanced Search. Beginning in 2016, the County Health Rankings reported the Drinking Water Violations as a Yes/No variable that indicates the presence or lack of a violation in any community water system. Previously, this measure indicated an estimate of the percentage of the county population impacted by any health-based drinking water violations throughout the year. However, we were advised by local agencies that it is difficult to determine the exact population impacted by any specific violation, as water systems have water system partnerships with other jurisdictions.

Measure limitations

There are a number of limitations associated with this measure: 

  • The number of violations within each system is not taken into account, and estimates are not available for the number of people who consume infected water or get ill from consumption.
  • Not all violations are equivalent; some violations occur but are addressed quickly, while some violations can linger for years. Violations could be slightly over or much higher than the Maximum Contaminant Level. 
  • Testing date, frequency, location, and type can play a role in violation detection.
  • This measure only includes data on community water systems and does not include private wells.
  • The required reporting of water quality tests is often based on annual and/or system-wide averages of individual sampling results. For example, Community Water Systems (CWS) may be required to sample at four different locations but report only the average.
  • Violations identified as health-based have changed over time.
Can This Measure Be Used to Track Progress

This measure is not appropriate for measuring progress. 

Data Source

Years of Data Used


Safe Drinking Water Information System

From EPA:

The Safe Drinking Water Information System (SDWIS) contains information about public water systems and their violations of EPA's drinking water regulations, as reported to EPA by the states. These regulations establish maximum contaminant levels, treatment techniques, and monitoring and reporting requirements to ensure that water systems provide safe water to their customers.

Digging Deeper
Subcounty Area1

Drinking water violations can be measured through many local data sources. In addition, specific data on water systems such as type of violation, containment, and date of violation can be found at the following website: https://www3.epa.gov/enviro/facts/sdwis/search.html.


[1] Gunther CF, Brunkard JM, Yoder JS, Roberts VA, Capenter J, et al. Causes of Outbreaks Associated with Drinking Water in the United States from 1971 to 2006. Clinical Microbiology Reviews. 2010 July 7.
[2] Safe Drinking Water. cdc.gov. https://www.cdc.gov/safewater/disease.html
[3] Hunter PR, MacDonald AM, and Carter RC. Water Supply and Health. Public Library of Science, Medicine. 2010; 7(11). 
[4] Alzahrani, F., Collins, A. R., & Erfanian, E. (2020). Drinking water quality impacts on health care expenditures in the United States. Water Resources and Economics, 32, 100162.
[5] Allaire M, Wu H, Lall U. National trends in water quality violations. Proceedings of the National Academy of Sciences. 2018 Feb; 115(9):2078-2083.

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When it comes to developing and implementing solutions to problems that affect communities, evidence matters. The strategies below give some ideas of ways communities can harness evidence to make a difference locally. You can learn more about these and other strategies in What Works for Health, which summarizes and rates evidence for policies, programs, and systems changes.

Encourage methods of soil cultivation that keep at least one-third of cultivated soil covered with the previous year’s crop residue (e.g., mulch till, ridge till, strip till, or no-till)
Support site-specific plans for crop production that match nutrient applications to crop needs, typically with agricultural best management practices
Use pervious concrete, porous asphalt, permeable interlocking pavers, open-jointed blocks or cells, or other permeable pavement in individual or commercial development efforts; also called porous or pervious pavement
Use ready-made or home constructed barrel systems to collect and store rainwater from rooftops that would otherwise flow to storm drains and streams
Establish local regulations for confined animal feeding operations (CAFOs) that address location, size, facility management, and pollution contributions to complement US EPA regulations

The County Health Rankings provide a snapshot of a community’s health and a starting point for investigating and discussing ways to improve health. Select a state and a measure below to see what’s happening locally.