What Does an EPA Water Violation Actually Mean for Your Health?

You got a notice in the mail. Or you ran your water system through a database and saw a red flag. Your public water system has an EPA violation. Now what?

The first thing to understand: not all violations are created equal. Some mean your water had a dangerous contaminant above the legal limit. Others mean your public water system forgot to file paperwork. Here's how to tell the difference — and what to actually do.

The Two Types of EPA Violations

1. Health-Based Violations

These are the ones that matter for your health. A health-based violation means a contaminant was detected above the EPA's Maximum Contaminant Level (MCL) — the legal limit — or that a required treatment technique wasn't being used. Examples:

Maximum Contaminant Level (MCL) violations: Nitrates above 10 mg/L, arsenic above 10 ppb, lead above 15 ppb (at the 90th percentile), coliform bacteria detected, disinfection byproducts (THMs above 80 ppb, HAA5 above 60 ppb).

Treatment technique (TT) violations: The public water system failed to properly disinfect water, failed to control corrosion (which causes lead leaching), or failed to filter surface water properly.

2. Monitoring and Reporting Violations

These are administrative violations — the public water system failed to test for something on schedule, or failed to report results to the state on time. They do NOT necessarily mean there's a problem with your water. But they do mean you have less information than you should. Take these as a reason to be more vigilant, not an emergency.

The Notice You Received

When a public water system has a health-based violation, federal law requires them to notify customers within a specific timeframe depending on the severity. The notice must tell you:

• What contaminant exceeded the limit and by how much • What the potential health effects are • What the public water system is doing to fix it • What you can do in the meantime (alternative water sources, boiling, etc.)

Read the notice carefully. The most important line is the one that tells you what the contaminant is and what the health risk is for different populations (infants, pregnant women, immunocompromised individuals are always at higher risk).

Meeting the Legal Limit ≠ Safe

Here's something that surprises most people: your water can meet all EPA standards and still contain contaminants at levels that independent health scientists consider harmful.

EPA limits are set by balancing health risk against what's technically and economically feasible to achieve — not purely on what's safest. For example, the EPA's arsenic limit is 10 ppb, but the WHO recommends 10 ppb as a maximum and notes that even lower is better. The EPA's lead "action level" is 15 ppb, but the CDC says there's no safe level of lead.

The Environmental Working Group (EWG) maintains a health guideline database that uses more conservative, health-only thresholds. Many water systems that pass all EPA tests still exceed EWG health guidelines for chromium-6, PFAS, disinfection byproducts, and other contaminants.

What to Do After a Violation

Short term

Follow the public water system's instructions. If there's a boil water advisory, boil. If they say use alternative water, use bottled water for drinking and cooking. Don't use tap water for infant formula during a microbiological violation.

Medium term

Install a certified filter appropriate for the contaminant that violated. Nitrate violation? You need an RO system — the only technology that removes nitrates. Lead violation? NSF 53 certified filter or RO. Disinfection byproduct violation? Certified carbon block or RO. PFAS? RO or NSF 58 certified filter.

Long term

Check your water regularly. Enter your ZIP on WaterCheckup to see your public water system's current violation history and contaminant levels. Sign up for your public water system's alert list if they have one. Read your annual CCR (Consumer Confidence Report) when it arrives.

How to Look Up Your Violations

Enter your ZIP code above to see your water system's current EPA SDWIS data — including any active violations, historical violations, and the contaminants your public water system monitors for. It's free and pulls directly from EPA's database in real time.

You can also search EPA's ECHO database directly at echo.epa.gov, but WaterCheckup presents the same data in a format that's actually readable.