Understand the evidence behind your water.
Enter your address, city, ZIP, or water system. We find the utility that serves you, read its public record, and show every measurement against the limit set to protect you.
From your address to the evidence, in four steps
- 01Find the supplier
Turn an address, city, or ZIP into the public water system that actually serves it.
- 02Read public records
Pull that system’s Consumer Confidence Report and state SDWIS monitoring.
- 03Compare with benchmarks
Read each measured value against its enforceable federal limit and health goal.
- 04Inspect the evidence
Trace every number back to its source document, method, and sample date.
Every drop is a published city report
- 20,804
- lab measurements, each sourced
- 15
- contaminants tracked against limits
Browse by state, or go straight to a city
- 01Texas364 cities
- 02California341 cities
- 03Illinois193 cities
- 04Florida180 cities
- 05Massachusetts163 cities
- 06Tennessee143 cities
Start with what people ask about
Each one opens with its benchmark and what kind of limit it is, before any value.
What public records can tell you
- Which public system serves your address, city, or ZIP.
- Every contaminant that was measured, against its federal limit.
- The exact source document and date behind each value.
- How your system compares to others on the same evidence.
What they can’t see
- Exactly what’s flowing from your specific tap right now.
- Anything about a contaminant that was never sampled.
- A substitute for a certified in-home water test.
- Changes since the utility’s last published report.
Know, then reduce, then choose
The order is fixed. Treatment comes after the record, and products come after the treatment.
- KNOWRead your system’s record
Every measured value next to its limit, with the source and date.
In New York CityLead (90th percentile) 10 µg/L · Below the 15 µg/L federal action levelFind my water → - REDUCEUnderstand the method before the model
Each treatment method, what it removes, and what it does not, from its own record.
Methods on recordReverse Osmosis (RO), Activated Carbon Filtration (Solid Block / GAC), Ion Exchange (Specialized Resins)Compare treatments → - CHOOSECommercialChoose a product by its certification
Offers never change which products appear or their order.
The product register19 analysed, 13 with a verified certificationExplore product analyses →
Products, read against their certification records
Certification is the claim a lab verified, not the claim on the box. We check each product’s listed compounds against the finding you came from.
Research built on the same records
See exactly how we know
Every number on PurityMap carries the same four-link chain. Here is one, from New York City’s lead (90th percentile) result.
- 1 · Measurement10 µg/LThe 90th-percentile tap result was 10.0 µg/L (below the 15 µg/L action level).
- 2 · Benchmark15 µg/L federal action levelTriggers treatment steps; not an MCL
- 3 · SourceLead & Copper Rule 90th-percentile: NEW YORK CITY SYSTEM (NY7003493)The public record behind the value
- 4 · MeaningBelow the 15 µg/L federal action levelHome plumbing can add lead this record can’t see