Drinking water guide
How to Check Your Water System
A practical guide to looking up your water system's compliance record, understanding what violations mean, and knowing what steps to take if concerns arise.
Key Takeaway
Every public water system serving 25 or more people has a compliance record in EPA's SDWIS database. PlainWater makes it searchable. When reviewing a system, look at: violation type (health-based vs. monitoring), whether violations are resolved, PFAS detection results, and the system's most recent Consumer Confidence Report. A few past monitoring violations are common and less worrying than an active health-based violation.
Step 1: Find Your Water System
The first step is identifying which public water system serves your address. Most households are served by a community water system, a utility, municipal water department, or water district. To find yours:
- Check your water bill: The name of your water system is usually printed on it, along with a PWS ID (Public Water System ID).
- Search PlainWater: Use the water systems search to look up by city, county, system name, or state.
- Browse by location: View all water systems in your state or your county.
- Contact your utility: Call them directly, they can confirm your service area and provide their PWS ID.
If you rely on a private well, PlainWater does not cover your water, private wells are not regulated under the Safe Drinking Water Act. Contact your county health department for well testing guidance.
Step 2: Review the Violation History
Once you locate your water system on PlainWater, review its violation record with these criteria in mind:
What to look for
- Violation type: Health-based violations (MCL exceedances, treatment technique failures) are more serious than monitoring and reporting violations.
- Resolution status: Is the violation marked as resolved? What was the return-to-compliance date? An unresolved violation is more concerning than a historical one.
- Recency: Violations from 10 years ago with a return-to-compliance date are far less alarming than a violation from the past 12 months.
- Pattern: Repeated violations of the same type across multiple years suggest a systemic problem rather than a one-time event.
- Contaminant severity: An E. coli MCL violation is an immediate acute risk. A nitrate violation in a rural system serving agricultural communities is common and often corrected quickly. Context matters.
Putting it in context
Many systems have at least a few monitoring violations in their history, these are common, especially for small systems managing complex quarterly testing schedules. What you want to avoid is a pattern of health-based violations, active unresolved violations, or enforcement actions indicating the system is struggling to comply.
Step 3: Check PFAS Results
The EPA's UCMR5 program tested most large public water systems for 29 PFAS compounds between 2023 and 2025. On PlainWater, each system with UCMR5 data shows:
- Whether the system was tested at all
- Which PFAS compounds were detected and at what concentrations
- How detected levels compare to EPA's 2024 MCLs (4 ppt for PFOA/PFOS)
- The number of individual PFAS contaminants found
If your system detected PFAS above the new MCLs, it will need to install treatment by 2029 (a 2031 extension has been proposed by EPA but is not yet final as of May 2026). In the meantime, a point-of-use reverse osmosis filter certified to NSF Standard 58 can reduce PFAS in your home tap water. See the PFAS guide for full context on these standards.
Step 4: Read Your Consumer Confidence Report
All community water systems serving 25 or more people must publish an Annual Water Quality Report (also called a Consumer Confidence Report or CCR) each year by July 1st. This report is your primary source for:
- A complete list of regulated contaminants detected in the past year and their concentrations
- The source of your drinking water (lake, river, groundwater aquifer)
- Any violations that occurred and how they were addressed
- Educational information about contaminants of local concern
Find your CCR at the EPA's database (epa.gov/ccr), your utility's website, or contact your utility directly. Large systems must make it available online; small systems may mail it.
Step 5: Contact Your Utility or Health Department
If you have found a concern in your water system's record, an active violation, elevated PFAS results, or an unresolved enforcement action, here is how to follow up:
- Contact your water utility directly: Ask specifically about the violation, the current status, and any treatment changes underway. Utilities are required to answer public inquiries.
- Contact your state drinking water program: State primacy agencies have authority over local water systems. They can tell you whether enforcement actions are open or compliance has been restored.
- Request private lab testing: If you remain concerned, contact a state-certified laboratory for independent testing of your tap water.
- EPA Safe Drinking Water Hotline: Call 1-800-426-4791 for referrals to your state drinking water agency and certified labs.
For context on how your system compares to others in your area, browse county-level water quality data or view statewide violation patterns on your state page.
Quick Reference: Action Thresholds
| What You Find | Suggested Action |
|---|---|
| Old, resolved monitoring violations only | No immediate action needed. Monitor future CCRs. |
| Active monitoring violation (current year) | Contact utility. Request explanation and testing timeline. |
| Resolved health-based violation (past 5 years) | Read CCR. Contact utility if no explanation provided. |
| Active health-based MCL violation | Contact utility and state agency. Consider point-of-use filter. |
| PFAS detected above 4 ppt (PFOA/PFOS) | Contact utility about treatment plan. Consider NSF-58 RO filter. |
| Boil water notice active | Boil water for all drinking, cooking, and brushing teeth. Follow utility instructions. |
Frequently Asked Questions
How do I find out which water system serves my address?
Most community water utilities publish their service territory boundaries on their websites. You can also use the EPA's ECHO (Enforcement and Compliance History Online) tool at echo.epa.gov to search for water systems by state, county, or ZIP code. Your water bill will also identify your water system by name and often include the PWS ID, a unique identifier that appears in SDWIS records. PlainWater lets you search by system name, city, or ZIP directly.
What is a Consumer Confidence Report (CCR) and where do I find it?
A Consumer Confidence Report (also called an Annual Water Quality Report) is a document all community water systems serving 25 or more people must provide to their customers each year by July 1st. It lists contaminants detected, comparison to MCLs, the source of your water, and any violations from the previous calendar year. Your utility must mail or deliver it, or make it available online. The EPA's CCR database at epa.gov/ccr lets you search by zip code for your most recent report.
If my water system has violations, is my water unsafe to drink?
Not necessarily, it depends entirely on the type and recency of the violation. A resolved monitoring and reporting violation from two years ago means a test was missed, but does not confirm the water was ever unsafe. An active health-based MCL violation for a serious contaminant is more concerning and may come with a "do not drink" advisory or boil water notice. Always check whether violations are marked as resolved and whether your utility issued any public health notices. Contact your utility directly for the most current assessment.
What is a boil water notice and when is one issued?
A boil water notice is a public health advisory issued when a water system cannot guarantee microbiological safety, typically following a loss of pressure, infrastructure failure, flooding, or detected microbial contamination. During a boil water notice, residents should bring tap water to a rolling boil for at least one minute (three minutes at elevations above 6,500 feet) before drinking, cooking, or brushing teeth. Boil water notices do not address chemical or PFAS contamination, boiling actually concentrates these substances.
How can I test my home water privately?
Certified private laboratory testing is available for homeowners concerned about their tap water or private wells. The EPA's Safe Drinking Water Hotline (1-800-426-4791) can refer you to state-certified laboratories. For comprehensive screening, request a panel that includes volatile organic compounds (VOCs), heavy metals, nitrate, coliform bacteria, and PFAS. Well owners should test annually since their water is not covered by public water system monitoring.
My water comes from a private well. Does PlainWater cover it?
PlainWater covers public water systems regulated under the Safe Drinking Water Act, these serve 25 or more people or have 15 or more service connections. Private wells are not covered by SDWIS because they are not subject to federal regulation. If you rely on a private well, you are responsible for testing it yourself. The CDC and state health departments recommend annual testing at minimum. Your county health department often offers low-cost testing programs and can advise on what contaminants are most relevant for your area.
Sources
- U.S. Environmental Protection Agency, Safe Drinking Water Information System (SDWIS)
- EPA, Consumer Confidence Reports (Annual Water Quality Reports)
- EPA, Safe Drinking Water Hotline: 1-800-426-4791
- EPA, ECHO (Enforcement and Compliance History Online): echo.epa.gov
- Centers for Disease Control and Prevention, Water Fluoridation and Private Wells guidance
- PlainWater, 143,000 water systems, 1.26 million violations (2025)
This content is for informational purposes only. If you have concerns about your drinking water, contact your local water utility or state health department.