Private Well Water Testing in Wyoming
County-by-county USGS area-risk estimates for private wells across Wyoming — arsenic exceedance probability and private-well population — plus how to test your own well at a Wyoming-certified laboratory.
Wyoming private-well risk summary
Counties covered
23
Wyoming counties with modeled risk data.
People on private wells
area estimate111,164
estimated across covered Wyoming counties.
Average arsenic risk
area estimate5%
average modeled chance a well exceeds 10 µg/L arsenic across covered counties.
Wyoming counties
- Laramie County4% arsenic exceedance (area estimate)17,355 people on private wells
- Fremont County8% arsenic exceedance (area estimate)12,248 people on private wells
- Park County6% arsenic exceedance (area estimate)9,267 people on private wells
- Campbell County4% arsenic exceedance (area estimate)8,530 people on private wells
- Sheridan County4% arsenic exceedance (area estimate)7,860 people on private wells
- Sublette County7% arsenic exceedance (area estimate)5,518 people on private wells
- Lincoln County9% arsenic exceedance (area estimate)5,187 people on private wells
- Natrona County4% arsenic exceedance (area estimate)5,085 people on private wells
- Goshen County5% arsenic exceedance (area estimate)4,364 people on private wells
- Teton County5% arsenic exceedance (area estimate)4,246 people on private wells
- Albany County3% arsenic exceedance (area estimate)4,120 people on private wells
- Uinta County9% arsenic exceedance (area estimate)4,034 people on private wells
- Converse County4% arsenic exceedance (area estimate)3,648 people on private wells
- Sweetwater County10% arsenic exceedance (area estimate)3,100 people on private wells
- Platte County4% arsenic exceedance (area estimate)3,064 people on private wells
- Crook County3% arsenic exceedance (area estimate)3,012 people on private wells
- Johnson County4% arsenic exceedance (area estimate)2,316 people on private wells
- Big Horn County6% arsenic exceedance (area estimate)2,286 people on private wells
- Washakie County6% arsenic exceedance (area estimate)2,067 people on private wells
- Carbon County4% arsenic exceedance (area estimate)1,594 people on private wells
- Weston County4% arsenic exceedance (area estimate)1,020 people on private wells
- Niobrara County4% arsenic exceedance (area estimate)704 people on private wells
- Hot Springs County5% arsenic exceedance (area estimate)539 people on private wells
Find a Wyoming-certified testing lab
Get your well tested at a Wyoming-certified laboratory. We list certification programs by state.
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Upload my well testThese figures are USGS area estimates: statistical groundwater models describing how likely elevated contaminant levels are across a county. They are not designed to predict the concentration in any single well. Only testing your own well reveals its water quality.
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