City ranking · Purity Score
Large US Cities With the Highest-Scoring Tap Water Records (2026)
50 cities ranked by purity score, from public EPA records (EPA UCMR 5 (2024) and Lead and Copper Rule records). Updated 2026-09-24. It ranks the published record, not which water is safest.
A ranking is not a safety verdict
This compares one published measure across cities. It does not summarize everything about a place, and it is not the water at a household tap.
Snapshot 2026-09-24 · cutoff EPA UCMR 5 (2024) and Lead and Copper Rule records A snapshot is immutable: its ordering belongs to the stated date, data cutoff, methodology, and exclusions.
Methodology and limitations
How this snapshot is built
Every US city report serving at least 100,000 people, ordered by Purity Score and then by population served. 82 of the 435 qualifying cities score 100/100, so larger systems come first among ties. The score is computed only from contaminants measured in the published EPA record.
Reading the order
A high score means few or no measured exceedances in the record, not a guarantee about any tap. Cities with sparse monitoring can score higher simply because less was tested, and household plumbing can add lead after the water leaves the system.
Exclusions
0 excluded. Cities serving 100,000+ people without a computed Purity Score are excluded. Smaller systems are not ranked here because hundreds of them tie at 100.
The rankingEach row links to its full report. Rows appear in the snapshot’s published order: a comparison of one measure (purity score), not an overall safety order.
| # | City | Purity Score | On record | |
|---|---|---|---|---|
| 1 | Washington Suburban Sanitary CommissionWashington Suburban Sanitary Commission, MD | 100 / 100 | 1,900,000 people served | |
| 2 | East Bay MUDEast Bay MUD, CA | 100 / 100 | 1,442,800 people served | |
| 3 | San DiegoSan Diego, CA | 100 / 100 | 1,385,379 people served | |
| 4 | Gwinnett CountyGwinnett County, GA | 100 / 100 | 975,000 people served | |
| 5 | Sfpuc City DistributionSfpuc City Distribution, CA | 100 / 100 | 848,019 people served | |
| 6 | Oklahoma CityOklahoma City, OK | 100 / 100 | 644,000 people served | |
| 7 | AlbuquerqueAlbuquerque, NM | 100 / 100 | 560,326 people served | |
| 8 | Irvine Ranch DistrictIrvine Ranch District, CA | 100 / 100 | 444,800 people served | |
| 9 | Virginia BeachVirginia Beach, VA | 100 / 100 | 437,994 people served | |
| 10 | Greenville (sc2310001)Greenville (sc2310001), SC | 100 / 100 | 426,057 people served | |
| 11 | Winston-SalemWinston-Salem, NC | 100 / 100 | 391,900 people served | |
| 12 | Metropolitan District CommissionMetropolitan District Commission, CT | 100 / 100 | 390,887 people served | |
| 13 | Chesterfield CentralChesterfield Central, VA | 100 / 100 | 389,897 people served | |
| 14 | ToledoToledo, OH | 100 / 100 | 360,000 people served | |
| 15 | Manatee CountyManatee County, FL | 100 / 100 | 347,800 people served | |
| 16 | Alameda County DistrictAlameda County District, CA | 100 / 100 | 344,000 people served | |
| 17 | Loudoun - CentralLoudoun - Central, VA | 100 / 100 | 334,808 people served | |
| 18 | Henrico CountyHenrico County, VA | 100 / 100 | 330,000 people served | |
| 19 | BellevueBellevue, WA | 100 / 100 | 321,349 people served | |
| 20 | Glen Burnie-BroadneckGlen Burnie-Broadneck, MD | 100 / 100 | 290,606 people served | |
| 21 | Helix DistrictHelix District, CA | 100 / 100 | 277,668 people served | |
| 22 | Montgomery Ww SsbMontgomery Ww Ssb, AL | 100 / 100 | 276,000 people served | |
| 23 | Coachella Vwd: Cove CommunityCoachella Vwd: Cove Community, CA | 100 / 100 | 270,000 people served | |
| 24 | Northern Kentucky DistrictNorthern Kentucky District, KY | 100 / 100 | 259,949 people served | |
| 25 | Des MoinesDes Moines, IA | 100 / 100 | 246,055 people served | |
| 26 | Otay DistrictOtay District, CA | 100 / 100 | 238,008 people served | |
| 27 | FontanaFontana, CA | 100 / 100 | 237,700 people served | |
| 28 | Consolidated U D RutherfordConsolidated U D Rutherford, TN | 100 / 100 | 221,871 people served | |
| 29 | Waipahu-Ewa-WaianaeWaipahu-Ewa-Waianae, HI | 100 / 100 | 217,479 people served | |
| 30 | WilmingtonWilmington, NC | 100 / 100 | 212,227 people served | |
| 31 | Cucamonga Valley DistrictCucamonga Valley District, CA | 100 / 100 | 211,069 people served | |
| 32 | OxnardOxnard, CA | 100 / 100 | 200,232 people served | |
| 33 | McAllenMcAllen, TX | 100 / 100 | 189,957 people served | |
| 34 | Marin DistrictMarin District, CA | 100 / 100 | 186,895 people served | |
| 35 | OceansideOceanside, CA | 100 / 100 | 171,483 people served | |
| 36 | Moulton Niguel DistrictMoulton Niguel District, CA | 100 / 100 | 170,236 people served | |
| 37 | Elsinore Valley MwdElsinore Valley Mwd, CA | 100 / 100 | 169,455 people served | |
| 38 | LafayetteLafayette, LA | 100 / 100 | 169,389 people served | |
| 39 | Santa Margarita DistrictSanta Margarita District, CA | 100 / 100 | 168,289 people served | |
| 40 | TuscaloosaTuscaloosa, AL | 100 / 100 | 166,524 people served | |
| 41 | KentKent, WA | 100 / 100 | 166,421 people served | |
| 42 | SpartanburgSpartanburg, SC | 100 / 100 | 166,364 people served | |
| 43 | Spartanburg (sc4210001)Spartanburg (sc4210001), SC | 100 / 100 | 166,364 people served | |
| 44 | Lansing Board LightLansing Board Light, MI | 100 / 100 | 166,000 people served | |
| 45 | Pasadena PowerPasadena Power, CA | 100 / 100 | 164,344 people served | |
| 46 | HaywardHayward, CA | 100 / 100 | 162,954 people served | |
| 47 | AlexandriaAlexandria, VA | 100 / 100 | 159,200 people served | |
| 48 | SunnyvaleSunnyvale, CA | 100 / 100 | 157,566 people served | |
| 49 | Onslow WtrOnslow Wtr, NC | 100 / 100 | 156,755 people served | |
| 50 | RosevilleRoseville, CA | 100 / 100 | 155,612 people served |
Comparable does not mean complete.
This ranking compares cities on one measure. It never replaces a full system report, a city-resolution check, or a certified household test, and missing monitoring is excluded, never scored as favorable.