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Updated 2026-09-16
State water report

Wyoming Water Quality: 12 Cities Ranked by the Records

Water quality across 12 cities in Wyoming, drawn from EPA drinking-water records. Each city page shows the measured contaminants and a reproducible Purity Score.

Finding by finding

What Wyoming's records show

Counts of cities whose serving system reported each result. There is no statewide score: PurityMap does not average local records into a statewide safety verdict.

PFAS above a 2024 limit

MCL

1of 12 cities

Cities whose system reported a PFAS above its federal limit.

PFOS in Wyoming →
City rankings

Wyoming cities ranked by the records

Highest first. A summary of each serving system’s record, not a safety verdict.

  1. 1
    SheridanSHERIDAN, CITY OF · WY5600052
    Report →
  2. 2
    CodyCODY, CITY OF · WY5600207
    Report →
  3. 3
    CasperCASPER, CITY OF · WY5601415
    Report →
  4. 4
    LaramieLARAMIE, CITY OF · WY5600029
    Report →
  5. 5
    EvanstonEVANSTON, CITY OF · WY5600150
    Report →
  6. 6
    Green RiverGREEN RIVER, CITY OF · WY5601181
    Report →
  7. 7
    Rock SpringsROCK SPRINGS, CITY OF · WY5601182
    Report →
  8. 8
    GilletteGILLETTE, CITY OF · WY5600019
    Report →
  9. 9
    South Cheyenne DistrictSOUTH CHEYENNE WATER & SEWER DISTRICT · WY5600239
    Report →
  10. 10
    CheyenneCHEYENNE BOARD OF PUBLIC UTILITIES · WY5600011
    Report →

Showing the top 10 of 12 scored cities.

See all 12 in the table

12 cities, highest Purity Score first

  1. 1Sheridan
    SHERIDAN, CITY OF · PWSID WY5600052 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  2. 2Cody
    CODY, CITY OF · PWSID WY5600207 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detectedNot detected
  3. 3Casper
    CASPER, CITY OF · PWSID WY5601415 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 1 µg/LDetected
  4. 4Laramie
    LARAMIE, CITY OF · PWSID WY5600029 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 1.28 µg/LDetected
  5. 5Evanston
    EVANSTON, CITY OF · PWSID WY5600150 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 0.73 µg/LDetected
  6. 6Green River
    GREEN RIVER, CITY OF · PWSID WY5601181 · Purity Score 98/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 2 µg/LDetected
  7. 7Rock Springs
    ROCK SPRINGS, CITY OF · PWSID WY5601182 · Purity Score 97/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 3 µg/LDetected
  8. 8Gillette
    GILLETTE, CITY OF · PWSID WY5600019 · Purity Score 95/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 4 µg/LDetected
  9. 9South Cheyenne District
    SOUTH CHEYENNE WATER & SEWER DISTRICT · PWSID WY5600239 · Purity Score 93/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 6 µg/LDetected
  10. 10Cheyenne
    CHEYENNE BOARD OF PUBLIC UTILITIES · PWSID WY5600011 · Purity Score 83/100 (Good) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 15 µg/LDetected
  11. 11Jackson
    JACKSON, TOWN OF · PWSID WY5600213 · Purity Score 72/100 (Fair) · Confidence: moderate · Assessed at the water-system level
    PFAS detected below EPA limits; lead 1 µg/LDetected
  12. 12Riverton
    RIVERTON, CITY OF · PWSID WY5600047 · Purity Score 48/100 (Poor) · Confidence: moderate · Assessed at the water-system level
    PFHxS 37 ng/L, 4× the EPA limit (+1 more PFAS above)Above reference
End of list.

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no state score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works. See how Wyoming compares with other states.

By contaminant

PFAS and lead in Wyoming

Counties

Wyoming counties

10 counties with city reports
Suppliers

Largest water systems

All water systems →
Full indexAll 12 Wyoming city reports, A–Z
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Questions

Wyoming water, frequently asked

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How does Wyoming tap water compare across cities?

PurityMap ranks 12 cities in Wyoming by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Sheridan's main water system: SHERIDAN, CITY OF · PWSID WY5600052 · Purity Score 100 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Wyoming cities have PFAS above the federal limit?

1 city of 12 had at least one regulated PFAS (PFOA, PFOS or PFHxS) measured above the 2024 federal limit in EPA's UCMR 5 testing, including Riverton (PFHxS 37 ng/L). PFAS were detected at any level in 2.

Is there lead in Wyoming tap water?

Utilities report lead as a 90th-percentile result from home taps. 10 of 12 Wyoming cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Limits, sources and corrections

A statewide page cannot tell you what reaches a specific address. Water quality varies by supplier, sampling period and household plumbing; open a city report for the evidence behind a local result.

Sources: EPA UCMR 5 (PFAS, 2024), SDWIS Lead and Copper Rule 90th-percentile results and health-based violations, and utility Consumer Confidence Reports where on file. Every city report links its dated source records.

Updated 2026-09-16. How PurityMap analyzes water data · Report an error