EPA Water Violations: What They Mean for Your Tap Water

The EPA tracks every violation of the Safe Drinking Water Act across every public water system in America. These violations range from minor paperwork issues to serious health-based contamination events. Understanding what these violations mean — and what they do not mean — is essential for anyone researching water quality in their county.

Across all US counties, 860 have zero recorded health-based violations, while 2,207 have at least one. The counties with the most violations tend to share common characteristics: older infrastructure, rural water systems with limited budgets, and heavy agricultural or industrial activity nearby.

Types of EPA Water Violations

Not all water violations are created equal. The EPA categorizes violations into several tiers, each with different implications for public health:

Health-Based Violations (Tier 1 and Tier 2)

These are the most serious violations. They occur when water exceeds the Maximum Contaminant Level (MCL) for a regulated substance — meaning the water contains more of a harmful contaminant than federal law allows. Common triggers include:

• Coliform bacteria or E. coli detection — indicates potential fecal contamination
• Lead and copper exceedances — often caused by corroding pipes and plumbing
• Nitrate levels above 10 mg/L — a particular concern for infants, often linked to agricultural runoff
• Disinfection byproduct levels (THMs, HAAs) — formed when chlorine reacts with organic matter
• Arsenic above 10 ppb — naturally occurring in some groundwater sources

Monitoring and Reporting Violations

These violations occur when a water system fails to test its water on schedule or fails to submit test results to the state. While not a direct indicator that water is contaminated, monitoring violations are a red flag — if a system is not testing, contamination could go undetected.

Small rural water systems are disproportionately affected by monitoring violations. Limited staff, tight budgets, and geographic isolation make it harder to meet testing schedules. A county with many monitoring violations may not have worse water, but it has less certainty about its water quality.

Treatment Technique Violations

These occur when systems fail to follow required treatment procedures — for example, not maintaining proper disinfection levels or not filtering surface water adequately. Even if test results are clean, failing to follow treatment protocols increases the risk of future contamination events.

Counties with the Most Health-Based Violations

The following counties have the highest recorded health-based violation counts in the EPA SDWIS database:

What a Violation Means for Your Tap Water

A violation on record does not necessarily mean your tap water is currently unsafe. Here is what to understand:

• Most violations are resolved. Water systems are required to take corrective action, and most do. A violation from 2020 may be fully resolved today.
• Boil-water notices are issued for acute threats. If your water poses an immediate health risk, your utility must notify you within 24 hours and often issues a boil-water advisory.
• Violation counts are cumulative. A county with 15 violations may have had all 15 in one bad year and been clean ever since — or it may have a chronic problem. Context matters.
• Not all contaminants are equally dangerous. A coliform violation is more concerning than a disinfection byproduct exceedance, even though both are "health-based violations."

What You Can Do

If your county has a lower water quality score or a history of violations, there are practical steps you can take:

• Request your water system's Consumer Confidence Report (CCR). Every public water system must publish an annual report detailing what was found in your water. This is the most specific data available for your exact system.
• Consider a home water test. Independent testing kits can detect lead, bacteria, nitrates, and other contaminants. This is especially important if you have older plumbing or a private well.
• Use a certified water filter. NSF-certified filters can remove specific contaminants. Match the filter to your concerns — a carbon filter handles chlorine and taste, while a reverse osmosis system handles lead and arsenic.
• Check EPA ECHO directly. For the most up-to-date violation data for your specific water system, search the EPA ECHO database at echo.epa.gov.

Methodology

Violation data comes from the EPA Safe Drinking Water Information System (SDWIS), accessed through the ECHO API. Health-based violations include Maximum Contaminant Level (MCL) violations and Treatment Technique (TT) violations that pose a health risk. Violation counts are aggregated from all public water systems serving each county. Water quality scores use percentile-rank methodology across all US counties.