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PFAS in drinking water: Wyoming

EPA UCMR 5 results for 33 public water systems. 3 had at least one PFAS detected; 1 had a highest single PFOA or PFOS result above 4.0 ppt.

UCMR 5 is a one-time EPA monitoring program, not a compliance determination. The values shown are the highest single sample result at any of the system's sampling points; one result above 4.0 ppt does not mean the system violates the PFAS rule, which is judged on running annual averages under separate compliance monitoring. Results describe the public water system, not an individual home.

Water systemServesPFOA max (ppt)PFOS max (ppt)PFAS detected
Black Thunder Coal Mine
WY5600360
WrightNDND0
Buffalo, City Of
WY5600005
BuffaloNDND0
Casper, City Of
WY5601415
CasperNDND0
Cheyenne Board of Public Utilities
WY5600011
CheyenneNDND0
Cody, City Of
WY5600207
CodyNDND0
Douglas, City Of
WY5600137
DouglasNDND1
Evanston, City Of
WY5600150
EvanstonNDND0
First Fike Subdivision
WY5600194
RivertonNDND0
GTNP-Colter Bay Village
WY5680095
MooseNDND0
Gillette, City Of
WY5600019
GilletteNDND0
Green River, City Of
WY5601181
Green RiverNDND0
High Meadow Ranch
WY5601569
Sublette CountyNDND0
Jackson, Town Of
WY5600213
JacksonNDND1
Kemmerer-Diamondville JPB
WY5600028
KemmererNDND0
Lander, City Of
WY5600176
LanderNDND0
Laramie, City Of
WY5600029
LaramieNDND0
Lovell, Town Of
WY5600031
LovellNDND0
Mills, Town Of
WY5600036
MillsNDND0
Newcastle, City Of
WY5600256
NewcastleNDND0
Northwest Rural Water District, Wy
WY5601254
CodyNDND0
Powell, City Of
WY5600042
PowellNDND0
Rawlins Water Supply, City Of
WY5600045
RawlinsNDND0
Riverton, City Of
WY5600047
RivertonND78
Rock Springs, City Of
WY5601182
Rock SpringsNDND0
Sheridan Wy, City Of
WY5600052
SheridanNDND0
South Cheyenne Water & Sewer District
WY5600239
CheyenneNDND0
Torrington Municipal WS
WY5600164
TorringtonNDND0
USAF F.E. Warren AFB
WY5680122
CheyenneNDND0
Wardwell Water & Sewer District
WY5600067
MillsNDND0
Wheatland, Town Of
WY5600187
WheatlandNDND0
Worland Utilities Commission
WY5600197
WorlandNDND0
Ynp-Canyon Village
WY5680074
Yellowstone NpNDND0
Ynp-Old Faithful
WY5680085
Yellowstone NpNDND0

ND = not detected (below the 4 ppt UCMR 5 reporting level). Values are the highest single sample result, not an annual average.

Source: EPA UCMR 5 final occurrence data (EPA page last updated 2026-08-28; samples collected January 2023 – December 2025) ↗.

PFAS disclaimer: PFAS results are copied from EPA's UCMR 5 dataset and describe samples taken at a public water system's entry points between 2023 and 2025, not water at any specific address. Levels may have changed since sampling (for example, after new treatment). “Not detected” means below EPA's UCMR 5 minimum reporting level, not zero. This is not a compliance determination or a water test. Contact your water utility for current information.