waterbycounty
Compiled federal source snapshot

Wyoming Water Quality

Drinking water data for all 23 counties.

Avg SDWIS Compliance Index

33.8

Most Common Five-Year SDWIS Compliance Band

F

Counties with Data

23

of 23 total

County water atlas

Wyoming water signals by county

A state-level 2.5D view across drinking-water compliance, watershed impairment, monitoring density, and streamflow snapshot context. Pin any county, switch layers, then use the lens controls to compare index ranges, recorded violation rates, or impaired watersheds without leaving the page.

Counties

23

Avg SDWIS index

33.8

Watersheds

0

ATTAINS counties

Monitoring

23

16 fresh USGS snapshots

State atlas layers combine EPA SDWIS health-based violations, EPA ATTAINS 303(d) impairment assessments, EPA Water Quality Portal monitoring sites, and representative USGS NWIS streamflow gauges. Streamflow values appear only for fresh pipeline snapshots, not as a continuously updated stream. County pages include the observation time and year.

Prepared by ByCounty Editorial TeamPublished by WaterByCounty

Multi-source coverage in Wyoming

Beyond Drinking Water

EPA SDWIS

23/ 23

counties with drinking-water compliance data

185 health violations statewide (5yr)

EPA ATTAINS

—

No §303(d) assessments yet for Wyoming

EPA WQP

426

monitoring sites across 23 counties

106,864 total readings (5yr window)

USGS NWIS

16

counties with a fresh pipeline snapshot

2 above14 below

State atlas notes

What stands out in Wyoming

County water quality is not one number. The strongest read comes from comparing drinking-water compliance against watershed impairment, monitoring density, and streamflow context. Use these signals as a starting point, then open any county profile for source-level detail.

Compliance spread

Washakie County has the highest value in the published state SDWIS Compliance Index table at 86.2/100, while Niobrara County has the lowest at 2.5/100. That is a 83.7 point gap inside one state.

Zero health violations

1

3+ health violations

14

Monitoring hubs

Teton County129 sitesFremont County41 sitesPark County39 sites

Lowest flow reads

Sheridan County0%Niobrara County0%Uinta County1%

Highest fresh streamflow pipeline snapshots: Goshen County (244%, observation 2026), Teton County (172%, observation 2026), Sublette County (81%, observation 2026). These are source-data observations, not household tap-water conclusions.

All Wyoming Counties

CountySDWIS Compliance Index
Washakie County86.2
Albany County63.3
Sheridan County52.7
Campbell County52.0
Converse County49.7
Park County47.9
Uinta County47.9
Laramie County45.6
Sweetwater County43.4
Natrona County43.0
Big Horn County36.8
Hot Springs County35.4
Teton County30.7
Weston County30.3
Sublette County22.5
Fremont County21.0
Platte County17.8
Crook County14.7
Johnson County11.3
Lincoln County9.5
Goshen County7.3
Carbon County5.7
Niobrara County2.5

Frequently Asked Questions

Which Wyoming county has the highest SDWIS Compliance Index?
Washakie County has the highest SDWIS Compliance Index in the published Wyoming cohort at 86.2/100. This WaterByCounty relative comparison is not an EPA score and does not establish current conditions for a utility or address.
What does the Five-Year SDWIS Compliance Band mean?
The band is derived only from each county aggregation's recorded health-violation rate per 100,000 people served for the stated five-year source window. It is separate from the relative SDWIS Compliance Index and is not a current determination for a specific utility or address.
Which USGS streamflow records are shown across Wyoming?
WaterByCounty has 16 fresh USGS pipeline snapshots in the published Wyoming cohort. Each county page shows its observation timestamp and year. A pipeline snapshot is not a continuously updated reading or a tap-water safety measure.
Where can Wyoming residents find current official information?
Review the applicable utility's Consumer Confidence Report, active notices, and the state drinking-water agency. WaterByCounty's county-level historical aggregations do not establish the current status of a specific utility, address, private well, or household plumbing system.
What does Water Quality Portal monitoring volume show in Wyoming?
The published county records contain 106,864 results from 426 monitoring locations in the site's five-year aggregation. Monitoring volume does not by itself indicate better or worse water quality.

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. The WaterByCounty SDWIS Compliance Index reflects the recorded rate and is not an EPA score.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

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