About WaterQ
WaterQ makes US drinking water quality data accessible and understandable for everyone. We believe every person has the right to know what's in the water they drink.
Our Mission
The US Environmental Protection Agency (EPA) collects extensive data on public water systems through the Safe Drinking Water Information System (SDWIS). While this data is publicly available, it can be difficult for everyday consumers to access, interpret, and act upon.
WaterQ transforms this raw regulatory data into clear, actionable water quality reports for every public water system in the United States. Our goal is to empower communities with the information they need to advocate for clean, safe drinking water.
What We Provide
Water Quality Scores
Every water system receives a score from 0 to 100 based on contaminant test results and violation history, making it easy to understand overall water quality at a glance.
Contaminant Reports
Detailed breakdowns of every tested contaminant, including how measured levels compare to EPA Maximum Contaminant Levels (MCLs) and potential health effects.
Violation Tracking
Complete records of regulatory violations, including whether they have been resolved and their severity level.
Geographic Comparisons
Compare water quality across states, counties, and cities to understand regional patterns and identify areas of concern.
Data Sources
WaterQ aggregates data from several authoritative federal sources:
- EPA SDWIS — The Safe Drinking Water Information System is our primary data source, providing water system information, contaminant test results, and violation records for over 150,000 public water systems nationwide.
- USGS Water Quality Portal — Supplementary water quality monitoring data from the United States Geological Survey provides additional context and environmental water quality information.
- EPA Envirofacts — Additional environmental facility and compliance data that helps provide a more complete picture of water quality in each area.
Data is updated on a quarterly basis to align with EPA reporting cycles. For the most current information, please visit the Data Sources page.
Scoring Methodology
Our water quality scoring system evaluates each public water system on a 0–100 scale based on contaminant test results and violation history. The methodology accounts for:
- Contaminant concentrations relative to EPA Maximum Contaminant Levels (MCLs)
- Contaminant-specific risk weights (higher weight for known carcinogens and high-risk substances)
- Time decay to prioritize recent test results over older data
- Violation history and resolution status
For a detailed explanation, visit our Methodology page.
Contact
Have questions, feedback, or data correction requests? We'd love to hear from you.
Email: [email protected]
Disclaimer
The information provided on WaterQ is for general informational purposes only and should not be considered medical or health advice. Water quality data is based on publicly available EPA records and may not reflect the most current conditions at any particular water system.
If you have specific concerns about your drinking water quality, please contact your local water utility or consult a qualified water quality professional. In case of a water emergency, follow guidance from your local health department.