Why does water hardness vary across Wyoming?

Water hardness varies across Wyoming because utilities can use different groundwater wells, reservoirs, treatment plants, blends, and distribution zones. Private wells can also differ from nearby municipal water.

What city in Wyoming has the hardest water?

Rock Springs has the hardest water among higher-confidence Wyoming city pages at 944 PPM. Check the city page for local systems and ZIP codes before making treatment decisions.

Does this include municipal water, well water, or both?

The state report combines public water system records, utility reports, and USGS monitoring where available. Municipal treated-water records are preferred when present. Private well hardness can vary at the address level and should be confirmed with a local test.

How many water systems are in Wyoming?

Wyoming has 323 active community water systems serving 156 cities.

Water Hardness in Wyoming

Average: 298 PPMVery Hard156 cities323 water systems

State report

Is Wyoming Water Hard or Soft?

Wyoming water is very hard on average at 298 PPM (17.4 GPG). Local readings can vary by utility, aquifer, treatment plant, and private well use.

State average

298 PPM

Very Hard

Local coverage

156 cities

323 water systems

Source profile

114 ZIPs

direct or USGS-backed

Wyoming has mixed source coverage across treated-water records, USGS monitoring, and estimated fallback values.

Methodology Data sources Search by ZIP code

State data profile

How to read the Wyoming results

State pages are screening and comparison hubs. They summarize ZIP, city, and water-system patterns so you can find the local page that best matches your home or utility.

Direct or USGS-backed ZIPs

114 of 165

69% use treated-water records or USGS monitoring.

Estimated ZIP values

50 ZIPs

30% use nearby, county, or state-level fallback values.

Dataset update

March 9, 2026

Source coverage and rollups are rebuilt from the public dataset.

Use the source coverage below to judge how much local confirmation a specific city or ZIP needs. The methodology page explains the source hierarchy, weighting, and limitations.

State Average

298 PPM

Very Hard

Coverage

156 cities

323 water systems in the state rollup.

Data Source Coverage

ZIP-level source mix for Wyoming; higher direct and USGS coverage means less reliance on regional estimates.

165 ZIPs covered

Verified treated water

Utility, CCR, or state treated-water records

19%

32 ZIPs

High-confidence USGS

Environmental monitoring matched to local systems

50%

82 ZIPs

Estimated

Nearby, county, or state-level fallback values

30%

50 ZIPs

1 ZIPs have insufficient source data and are excluded from search sitemaps.

In Wyoming, 19% of ZIPs use verified treated-water records, 50% use high-confidence USGS monitoring, and 30% use estimates that should be confirmed locally for treatment decisions.

What the Data Shows in Wyoming

Hard water is common but not universal in Wyoming: 51% of classified ZIPs are hard or very hard.

Wyoming is mostly supported by high-confidence USGS monitoring, which is useful for regional hardness patterns and should be interpreted as environmental monitoring rather than a direct treated tap-water report for every home.

Use the city table below to compare local results. For estimated locations or unusually high readings, confirm with your utility or a home hardness test before sizing treatment equipment.

ZIP Hardness Distribution

Soft16% (27)

Slightly Hard15% (24)

Moderately Hard18% (29)

Hard10% (17)

Very Hard41% (67)

Treatment Takeaway

Wyoming has a mixed hardness profile. Some areas may benefit from softening, while others may only need point-of-use filtration or no hardness treatment at all.

How to Use This Data

Use the source coverage above to decide how much local confirmation you need for a specific city or ZIP code.

Source-Backed Water Systems in Wyoming

Large systems with treated-water reports or USGS monitoring behind the state rollup.

Review source labels

Water system	Hardness	Source label	Population
Cheyenne Board Of Public Utilities WY5600011 - Laramie County	60 PPM Slightly Hard	Annual Water Quality Report Verified - Annual Water Quality Report	64,165
Casper, City Of WY5601415 - Natrona County	120 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	59,000
Laramie, City Of WY5600029 - Albany County	80 PPM Slightly Hard	Annual Water Quality Report Verified - Annual Water Quality Report	32,395
South Cheyenne Water & Sewer District WY5600239 - Laramie County	60 PPM Slightly Hard	Annual Water Quality Report Verified - Annual Water Quality Report	10,000
Usaf F.E. Warren Afb WY5680122 - Laramie County	60 PPM Slightly Hard	Annual Water Quality Report Verified - Annual Water Quality Report	5,500
Vista West Water Company WY5600069 - Natrona County	120 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	1,600
Winchester Hills WY5600779 - Laramie County	60 PPM Slightly Hard	Annual Water Quality Report Verified - Annual Water Quality Report	1,078
West Winds WY5601619 - Laramie County	60 PPM Slightly Hard	Annual Water Quality Report Verified - Annual Water Quality Report	663

Useful Wyoming City Pages

Shortcuts to city pages backed by more ZIP-code or water-system data.

Cities With More Local Data

Cheyenne

3 ZIPs · 15 systems

Slightly Hard (60 PPM)

Casper

3 ZIPs · 12 systems

Moderately Hard (120 PPM)

Slightly Hard (80 PPM)

Wilson

1 ZIP · 23 systems

Moderately Hard (154 PPM)

Rock Springs

1 ZIP · 10 systems

Very Hard (944 PPM)

Prioritize cities with multiple ZIPs and systems, then use the local source badges to compare high-confidence USGS readings against estimated areas.

Top 10 Hardest Water Cities

#	City	Hardness
1	Rock Springs	Very Hard (944 PPM)
2	Thayne	Very Hard (607 PPM)
3	Grover	Hard (234 PPM)
4	Torrington	Hard (228 PPM)
5	Colter Bay	Moderately Hard (154 PPM)
6	Wilson	Moderately Hard (154 PPM)
7	Mills	Moderately Hard (138 PPM)
8	Moose	Moderately Hard (126 PPM)
9	Casper	Moderately Hard (120 PPM)
10	Laramie	Slightly Hard (80 PPM)

Top 10 Softest Water Cities

#	City	Hardness
1	Gillette	Soft (15 PPM)
2	Cheyenne	Slightly Hard (60 PPM)
3	Laramie	Slightly Hard (80 PPM)
4	Casper	Moderately Hard (120 PPM)
5	Moose	Moderately Hard (126 PPM)
6	Mills	Moderately Hard (138 PPM)
7	Colter Bay	Moderately Hard (154 PPM)
8	Wilson	Moderately Hard (154 PPM)
9	Torrington	Hard (228 PPM)
10	Grover	Hard (234 PPM)

All Cities in Wyoming

City pages marked Estimated use fallback values and should be confirmed with local testing or utility data.

AcmeVery Hard AftonVery Hard AlbinSlightly Hard AlcovaModerately Hard AlpineVery Hard AlvaSoft ArapahoeVery Hard ArvadaVery Hard AuburnHard BaggsVery Hard BairoilVery Hard BannerVery Hard BasinVery Hard BedfordVery Hard BeulahSlightly Hard Big HornVery Hard BondurantModerately Hard BoulderModerately Hard BuffaloVery Hard BufordSlightly Hard BurlingtonVery Hard BurnsSlightly Hard ByronHard CarpenterSlightly Hard CasperModerately Hard CentennialSlightly Hard CheyenneSlightly Hard ChugwaterHard ClearmontVery Hard CodySoft CokevilleHard Colter BayModerately Hard CoraModerately Hard CowleyVery Hard CrowheartVery Hard DanielModerately Hard DaytonVery Hard DeaverHard Devils TowerSoft DiamondvilleSoft DixonHard DouglasEstimatedVery Hard DuboisVery Hard EdgertonModerately Hard Elk MountainModerately Hard EmblemVery Hard EncampmentModerately Hard EtheteVery Hard EtnaVery Hard EvanstonSoft EvansvilleModerately Hard FairviewModerately Hard FarsonVery Hard Fishing BridgeSoft Fort BridgerSoft Fort LaramieHard Fort WashakieVery Hard FrannieSoft FrontierSoft GarrettSlightly Hard Gas HillsVery Hard GilletteSoft GlendoVery Hard GlenrockHard GrangerVery Hard Granite CanonSlightly Hard Grass CreekVery Hard Green RiverVery Hard GreybullVery Hard GroverHard GuernseyHard HannaVery Hard HartvilleModerately Hard Hawk SpringsSlightly Hard HillsdaleSlightly Hard Horse CreekSlightly Hard HudsonVery Hard HulettVery Hard HuntleySlightly Hard HyattvilleVery Hard Jay EmSlightly Hard Jeffrey CityVery Hard KayceeVery Hard KellyModerately Hard KemmererHard KinnearVery Hard KirbyHard La BargeModerately Hard LagrangeModerately Hard Lance CreekModerately Hard LaramieSlightly Hard LeiterVery Hard LinchModerately Hard LingleSoft Little AmericaVery Hard LonetreeSoft Lost SpringsHard LovellVery Hard LuskModerately Hard LymanModerately Hard LysiteVery Hard MandersonVery Hard ManvilleHard MarbletonVery Hard Mc KinnonEstimatedVery Hard Medicine BowSoft MeeteetseSoft MeridenSlightly Hard MidwestModerately Hard MillsModerately Hard MooseModerately Hard MoranModerately Hard Mountain ViewSoft NewcastleSlightly Hard OpalSoft OsageVery Hard OttoVery Hard ParkmanVery Hard PavillionVery Hard Pine HavenSoft PinedaleSoft Point Of RocksVery Hard PowellSoft RalstonSoft RanchesterVery Hard RawlinsVery Hard RecluseSoft RelianceEstimatedVery Hard RobertsonSoft Rock RiverSlightly Hard Rock SpringsVery Hard RozetSoft Ryan ParkHard SaveryVery Hard ShellVery Hard SheridanVery Hard ShoshoniVery Hard SmootVery Hard StoryVery Hard SundanceVery Hard SuperiorVery Hard Ten SleepVery Hard ThayneVery Hard Tie SidingSlightly Hard TorringtonHard UptonVery Hard Van TassellHard VeteranSlightly Hard WalcottModerately Hard WamsutterVery Hard WheatlandModerately Hard WilsonModerately Hard WorlandVery Hard WrightSoft WyarnoVery Hard YoderSoft