Fremont County Water Quality
Fremont County, Wyoming: one city report built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.
Highest result for each contaminant
One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.
Perfluorohexanesulfonic acid (PFHxS)RIVERTON, CITY OF10 ng/L federal MCL (2024) · US EPA37 ng/L
- RIVERTON, CITY OF37 ng/LSample date: 2023-05-09 to 2023-11-06
Perfluorooctanesulfonic acid (PFOS)RIVERTON, CITY OF4.0 ng/L federal MCL (2024) · US EPA7 ng/L
- RIVERTON, CITY OF7 ng/LSample date: 2023-05-09 to 2023-11-06
LithiumRIVERTON, CITY OF10 µg/L EPA health reference level (screening, not a legal limit) · US EPA11 µg/L
- RIVERTON, CITY OF11 µg/LSample date: 2023-05-09 to 2023-11-06
Lead (90th percentile)RIVERTON, CITY OF15 µg/L federal action level · US EPA3 µg/L
- RIVERTON, CITY OF3 µg/LMonitoring period: 2024–2026 (still open)
Perfluorobutanesulfonic acid (PFBS)RIVERTON, CITY OF2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPA13 ng/L
- RIVERTON, CITY OF13 ng/LSample date: 2023-05-09 to 2023-11-06
Perfluorohexanoic acid (PFHxA)RIVERTON, CITY OF400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLE28 ng/L
- RIVERTON, CITY OF28 ng/LSample date: 2023-05-09 to 2023-11-06
Perfluorobutanoic acid (PFBA)RIVERTON, CITY OFNo federal or state limit; shown for transparency5 ng/L
- RIVERTON, CITY OF5 ng/LSample date: 2023-05-09 to 2023-11-06
Perfluoroheptanoic acid (PFHpA)RIVERTON, CITY OFNo federal or state limit; shown for transparency3.6 ng/L
- RIVERTON, CITY OF3.6 ng/LSample date: 2023-05-09 to 2023-11-06
2 more contaminants detectedShow
Perfluoropentanesulfonic acid (PFPeS)RIVERTON, CITY OFNo federal or state limit; shown for transparency13 ng/L
- RIVERTON, CITY OF13 ng/LSample date: 2023-05-09 to 2023-11-06
Perfluoropentanoic acid (PFPeA)RIVERTON, CITY OFNo federal or state limit; shown for transparency19 ng/L
- RIVERTON, CITY OF19 ng/LSample date: 2023-05-09 to 2023-11-06
21 PFAS tested, none detected in this systemShow
Tested in this system: RIVERTON, CITY OF
- 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
- 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
- 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
- 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
- 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
- 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
- Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
- N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
- N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
- Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
- Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
- Perfluoro-3-methoxypropanoic acid (PFMPA)
- Perfluoro-4-methoxybutanoic acid (PFMBA)
- Perfluorodecanoic acid (PFDA)
- Perfluorododecanoic acid (PFDoA)
- Perfluoroheptanesulfonic acid (PFHpS)
- Perfluorononanoic acid (PFNA)
- Perfluorooctanoic acid (PFOA)
- Perfluorotetradecanoic acid (PFTA)
- Perfluorotridecanoic acid (PFTrDA)
- Perfluoroundecanoic acid (PFUnA)
Cities ranked by the records
Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county 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.
0of 1 city above the 15 µg/L action level
Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.
Lead in WyomingLargest water systems
- RivertonRIVERTON, CITY OF · WY560004710,330 served
Frequently asked
How does Fremont County tap water compare across cities?
PurityMap ranks 1 city in Fremont County 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 Riverton's main water system: RIVERTON, CITY OF · PWSID WY5600047 · Purity Score 51 (Poor) · 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 Fremont County cities had a PFAS sample above a 2024 EPA limit?
1 of 1 Fremont County city report had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Riverton (PFHxS 37 ng/L). That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. PFAS were detected at any level in 1.
Is there lead in Fremont County tap water?
Utilities report lead as a 90th-percentile result from home taps. 1 of 1 Fremont County 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.
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