About CheckYourWater

CheckYourWater is a free, open-source public service tool that shows Americans what PFAS “forever chemicals” are in their drinking water. We use data from the EPA’s Unregulated Contaminant Monitoring Rule (UCMR 5) — the most comprehensive PFAS testing program ever conducted in the United States, covering over 10,000 water systems.

The EPA has collected extensive PFAS testing data, but accessing it requires navigating technical databases designed for regulators, not residents. CheckYourWater translates this data into letter grades, plain-language explanations, and actionable next steps — so anyone can understand what’s in their water in seconds, not hours.

Unlike advocacy databases that use proprietary health guidelines, CheckYourWater uses the EPA’s own Maximum Contaminant Levels (MCLs) — the legally enforceable federal standards. Our grading algorithm is open source, so anyone can verify how grades are calculated. We have no ads, no donation prompts, no sponsored content, and no commercial partnerships.

• EPA UCMR 5 Occurrence Data
• EPA Safe Drinking Water Information System (SDWIS)
• PubChem chemical database

All data is from federal government sources and is in the public domain.

This tool has important limitations:

• Data reflects testing conducted between 2023 and 2026 and may not represent current water quality.
• Not all water systems were tested — smaller systems serving fewer than 3,300 people and private wells are generally not included.
• PFAS is just one category of drinking water contaminant. A good PFAS grade does not mean water is free of all contaminants.
• This tool provides information, not medical advice. Consult a healthcare provider for personal health concerns related to PFAS exposure.

CheckYourWater was built by Chris Trovato, an independent developer in San Diego, California. This is a personal public service project, not a commercial product. It is not affiliated with the EPA, any water utility, or any advocacy organization.

The complete source code for CheckYourWater is available on GitHub. The grading algorithm, data pipeline, and every line of code can be inspected, audited, and improved by anyone.

CheckYourWater.org is designed to be accessible to all users. We follow WCAG 2.1 AA guidelines: every page is keyboard navigable, the zip-code search works with screen readers, grade letters convey meaning alongside color, and the national map’s data is also available through the zip-code search for users who can’t interact with the map. If you encounter an accessibility issue, please email us at hello@checkyourwater.org.

• For press inquiries: press@checkyourwater.org
• For general questions: hello@checkyourwater.org
• For data corrections: data@checkyourwater.org