Drinking Water Quality Guides
Educational resources to help you understand drinking water safety, how EPA monitors public water systems, and what to do if your system has violations.
All guides reference EPA SDWIS and UCMR5 data covering 143,000 water systems, 1.26 million violations, and 1.93 million PFAS test results.
Understanding Water Quality Data
What EPA SDWIS tracks, how violations are classified, what Maximum Contaminant Levels mean, and how to interpret compliance records.
PFAS in Drinking Water
What PFAS "forever chemicals" are, why they matter for health, and how EPA's UCMR5 program monitors them across 143,000 water systems.
How to Check Your Water System
Step-by-step guide to looking up your water system, reading violation reports, and understanding what actions to take.
Is Your Tap Water Safe?
How to find your water system, read violation records, understand key contaminants and MCLs, and decide whether a filter makes sense.
PFAS Contamination by State
Which states have the highest PFAS detections from UCMR5 data, why contamination clusters near military and industrial sites, and the 2024 EPA limits.
Is My Water Safe? How to Read Your Water Quality Report
A step-by-step guide to reading your annual Consumer Confidence Report, understanding MCLs, interpreting violation records, and knowing when to consider filtration.
PFAS in Drinking Water: What You Need to Know
What forever chemicals are, how they contaminate water, what the 2024 EPA limits mean, how to check your water system, and what filtration options actually work.
Disclaimer: This content is for informational purposes only. If you have concerns about your drinking water, contact your local water utility or state health department.
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Methodology
Our guides are based on publicly available data from authoritative government sources. All statistics, ratings, and figures cited in these guides are drawn directly from official datasets and publications, with sources clearly referenced throughout.
We aim to present complex government data in plain language that is accessible to general audiences. When methodologies differ between data sources or change over time, we note these variations inline. Our editorial process includes regular reviews to ensure accuracy and timeliness of the information presented.