Hardness
Very Hard
245 PPM · 14.3 GPG
Local water dashboard
Official source aggregationA source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Yellowstone County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
245 PPM · 14.3 GPG
Compliance screen
Review needed
1 active health-based record
Lead 90th percentile
0.003 mg/L
20% of action level
Utility match
1 system
Serves 800 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
245 PPM
Parts per million
245
mg/L as CaCO₃ equivalent
Grains per gallon
14.3
1 GPG ≈ 17.1 PPM
What this means at home
At 245 PPM, mineral scale can build up on fixtures and heating elements, reduce soap lather, and leave visible spotting. Hardness is primarily an aesthetic and appliance concern—not itself a tap-water safety rating.
USGS sites used
11
Nearest site
56.7 mi
Observation range
Aug 23, 2016–Jun 12, 2018
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: BL-1 Afterbay below Yellowtail Dam (Lake, Reservoir, Impoundment).USGS source documentation ↗
Regional context
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Worden median
245 PPM
About the same1 indexed ZIP readings · Range 245–245 PPM
Montana median
122 PPM
123 PPM higher129 indexed ZIP readings · Range 0.2–799.5 PPM
EPA benchmark screen
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
Lead (PB90)
0.003 mg/L
Reported Dec 31, 2024
Copper (CU90)
2.52 mg/L
Reported Sep 30, 1999
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 0.003
EPA limit 0.015
Measured in mg/L
Local 2.52
EPA limit 1.3
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Nitrate-NitriteHealth-basedReported 11.2 MG/L | MT0000022 | Archived | Apr 1, 2025through Jun 30, 2025 |
| Nitrate-NitriteHealth-basedReported 12.4 MG/L | MT0000022 | Archived | Jan 1, 2025through Mar 31, 2025 |
| Lead and Copper Rule | MT0000022 | Unaddressed | Dec 30, 2024 |
| Consumer Confidence Rule | MT0000022 | Resolved | Oct 1, 2024through Dec 26, 2024 |
| Nitrate-NitriteHealth-basedReported 11 MG/L | MT0000022 | Archived | Jan 1, 2024through Mar 31, 2024 |
| Consumer Confidence Rule | MT0000022 | Resolved | Jul 1, 2022through Jul 18, 2022 |
| Lead and Copper Rule | MT0000022 | Resolved | Dec 30, 2021through Jan 14, 2022 |
| Nitrate-NitriteHealth-basedReported 10.02 MG/L | MT0000022 | Archived | Apr 1, 2021through Jun 30, 2021 |
| Surface Water Treatment RuleHealth-based | MT0000022 | Unaddressed | Mar 22, 2021 |
No reported violation does not prove that every contaminant was tested or absent; SDWIS measured values are incomplete and lag state records.
Solutions matcher
Matched to Worden ZIP 59088 using 245 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
245 PPM is 2× the high-hardness trigger used by this matcher.
Designed to reduce scale on fixtures, water heaters, glassware, and plumbing throughout the home.
Compare whole-house systemsDrinking water protection
Copper (90th percentile), Surface Water Treatment Rule have a measured benchmark flag or active health-based SDWIS record in this profile.
A certified multi-stage RO system targets a broader range of dissolved contaminants at the kitchen tap.
Explore under-sink filtrationAffiliate disclosure: we may earn a commission from qualifying purchases, at no added cost to you. Product matching is educational and does not replace certified water testing.
Frequently asked
EPA ECHO reports 1 active health-based violation among the associated community water systems. Review the affected utility's current notice and Consumer Confidence Report.
Nearby USGS observations produce an estimate of 245 PPM, or 14.3 grains per gallon, classified as very hard. This is not a household tap measurement.
At 245 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.