Terms of use

US Water Index is a product of Tidal Systems LLC. These terms are an agreement between you and Tidal Systems LLC (“Tidal Systems”, “we”, “us”), which operates US Water Index at uswaterindex.com. By using the site you accept them.

It presents drinking water monitoring data published by the United States Environmental Protection Agency, principally the fifth Unregulated Contaminant Monitoring Rule, scored against the federal limits set in 2024. It is an independent presentation of public data. It is not affiliated with, endorsed by or operated by the EPA or any government body.

• EPA reports by water system service area, and those are resolved here to counties. A figure describes a county, not your tap and not your building.
• Not tested is not the same as clean. EPA samples every large system and only a statistical sample of small ones, so a grey county means nobody looked, not that nothing is there.
• Private wells are not covered by federal monitoring at all and appear nowhere in this data.
• Monitoring data is a snapshot of when a sample was taken. Water quality changes, and this site can be out of date without saying so.

Nothing here is medical, health, legal or professional advice, and it is not a substitute for testing your own water. Do not use it to make a decision about your health, and do not treat it as a verdict on the water coming out of your tap.

If you are concerned about your water, contact your water utility for their most recent consumer confidence report, or have your own supply tested. If you are making a purchasing decision, verify the underlying figures against the EPA source that every county page links to.

A county may carry a placement from a water treatment company that pays for it. That placement is advertising. It is not a recommendation, not an endorsement, and not a statement that the company is suitable for you or that its products will help.

Whether a county has a sponsor has no effect on the data shown for it. The readings, the scoring and the ranking are the same either way, and no sponsor can change, soften or remove a figure about their own territory.

If you ask to be contacted through a form on this site, your details go to a water treatment company, as set out in the privacy policy. Anything that follows is between you and that company.

• Placements are billed monthly through Stripe. Cancelling in the Stripe billing portal releases the counties straight away and they become available to somebody else.
• A county under a separate written sponsorship agreement is governed by that agreement, and it prevails over this page wherever the two differ.
• You are responsible for what your placement says. It must be accurate about your own business, and it must comply with the advertising law that applies to you.
• A placement can be removed if it is misleading, if it misrepresents the data on the page it sits on, or if payment fails.

• Do not scrape, bulk download or systematically extract the data or the county pages.
• Do not resell or redistribute the compiled dataset as your own.
• Do not attempt to reach accounts, records or administrative areas that are not yours.
• Do not use the contact forms to send anything other than a genuine enquiry.

The underlying EPA measurements are public records and are not owned by anyone. The compilation, scoring, maps, written material and design of this site belong to Tidal Systems LLC, and are not yours to republish without permission.

The site is provided as it is, without warranty of any kind. We do not promise that it is accurate, complete, current or continuously available. Federal source data can contain errors, and processing it can introduce more.

To the fullest extent the law allows, Tidal Systems LLC is not liable for any indirect, incidental or consequential loss arising from use of the site or reliance on anything shown on it. Where liability cannot be excluded, it is limited to the amount you have paid us in the twelve months before the claim, which for a reader is nothing.

Nothing here excludes liability that cannot lawfully be excluded.

These terms are governed by the laws of the State of North Carolina, United States.

These terms may change, and the date at the top changes with them. Questions go to aidenbird@uswaterindex.com.