Every drop of water has an address.

We don't make that call, and you should be wary of anyone who does without testing your tap. "Safe" depends on what's in the water, how much of it you drink, and who you are: an infant, a pregnant person or someone with a weakened immune system can be more sensitive than a healthy adult. What we give you is the evidence: what was measured, when, where, and how it compares with both the legal limit and the health-based limit.

If your water is within its legal limits, your utility is meeting federal law. If the Health view shows a reading beyond a health limit, that's information for you to weigh, not an emergency notice. Emergencies, like boil-water notices, come from your utility and your state, and AquaAlert™ is built to get those to you fast.

An AquaScore™ is a 0 to 100 rating of a water system's public record. Higher means fewer contaminants were found relative to health-based limits. Each reading is compared with its health benchmark, from public-health agencies such as EPA's health goals and California's public health goals. The comparisons are added together into one combined measure, and that measure is converted to the 0 to 100 scale. Any single contaminant at 10 times its health benchmark or more sets the score to 0, so one serious problem can't be averaged away by clean results elsewhere.

Every score also gets a plain band, TRACE, DETECTED, ELEVATED, HIGH or SEVERE, defined by the facts in the method, never by a score range. A second track rates the same readings against legal limits, and the distance between the two is the AquaGap™. The full method, version 2.0.0, is published, and an independent science panel is forming to review it.

Because the two limits answer different questions. A legal limit, the Maximum Contaminant Level, is set as close to the health goal as treatment technology and cost allow. A health goal is set on health alone, with no consideration of cost. For some contaminants the two are the same; for others, like lead, whose health goal is zero, they're far apart.

A system can meet every federal limit and still show readings beyond a health goal. That isn't a violation and it isn't a failure by your utility. It's how national standards are built, and it's true in every city. We show both so the people who want to know more than "legal" can see it.

Public records first: your utility's annual Water Quality Report (also called a Consumer Confidence Report), EPA's Safe Drinking Water Information System, and EPA's national surveys of unregulated contaminants (UCMR). Every number on a score card links to its source and carries its sample date.

Readings expire. Each contaminant has a freshness window in the method, and a reading older than its window is shown as old record and left out of the score and the band. Most utility data is updated once a year, so a score reflects the latest published record, not today's water. That's exactly the gap Guardians and AquaAlert™ are built to close.

No, unless it says "measured." Most scores are rated for a whole water system and matched to your ZIP code, so they're modeled for your address from the utility's records. Lead and copper are sampled at a small number of homes; everything else is mostly sampled at the treatment plant and in the city's pipes.

The last mile, from the curb to your tap, includes your service line and your home's plumbing, and it can change what comes out of your faucet. If your ZIP code is served by more than one utility, the system on your water bill is the one that counts. The only way to know your own tap is to test it, ideally with a certified laboratory.

Start with your utility: ask for its latest Water Quality Report and the results nearest you. Then test your tap through a state-certified laboratory, especially for lead if your home was built before 1986, when federal law restricted lead in new pipes, solder and fixtures. If you choose a filter, make sure it's certified by NSF® or another accredited body to remove the specific contaminant found at your tap; filters are certified one contaminant at a time.

For health questions, especially about infants, pregnancy or a medical condition, talk with your doctor. Nothing on this site is medical advice.

No one can pay to change a score, add one or remove one. Aquagenuity® doesn't sell water, filters or treatment, and nothing we rate is something we sell. Sponsors can fund programs like Guardians of H2O™, but they have no say over methods or results. The method is published and versioned, so anyone can see how a score was produced and which version produced it.

No. An AquaScore™ is an independent, data-derived index built from public records. It isn't a regulatory determination, a compliance finding, a product certification, a health assessment or medical advice, and it doesn't allege a violation by any utility. Aquagenuity® isn't a government agency or a laboratory and isn't affiliated with EPA. Compliance with federal and state law is determined by regulators. The fixed line on every score says it plainly: AquaScore describes what was measured or modeled against health benchmarks. It is not a determination that water is safe or unsafe to drink.

Tell us. Utilities, officials, labs and residents can send newer or corrected results to hello@aquagenuity.com, with the source document. We check it against the record, re-run the score if the data supports it, and keep a dated note of what changed and why. Our job is to keep the public record accurate, and corrections make it better.

We rate water one system at a time and add new systems every day, starting in Georgia; the coverage register shows every system we've rated and what's next. Until yours is rated, the federal limits still apply to your water, and your utility's Water Quality Report is public. Become a Guardian and we'll notify you the day your system is rated. Guardians also test the last mile, which helps us rate places nobody has measured.

A lot. Most of America's water has never been tested at the tap. Many contaminants have no federal limit at all, and some have no agreed health benchmark yet. Testing for unregulated contaminants happens in national survey rounds, years apart. Where we model instead of measure, we say so, we show how confident we are, and we list what we left out of the score and why. Saying what we don't know is part of the record.