Hardness
Very Hard
259.5 PPM · 15.2 GPG
Local water dashboard
Official source aggregationWater quality in Hardin, MT 59034
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Big Horn County.
1 reported benchmark flag
- Primary matched system
- Hardin City Of
- Source water
- Surface water + Groundwater
- County
- Big Horn County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
3 systems
Serves 3,500 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
259.5 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
259.5
mg/L as CaCO₃ equivalent
Grains per gallon
15.2
1 GPG ≈ 17.1 PPM
What this means at home
At 259.5 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
28
Nearest site
27.5 mi
Observation range
Jan 27, 2016–Sep 9, 2025
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
Is 59034 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Hardin median
260 PPM
About the same1 indexed ZIP readings · Range 259.5–259.5 PPM
Montana median
122 PPM
138 PPM higher129 indexed ZIP readings · Range 0.2–799.5 PPM
EPA benchmark screen
Contaminant snapshot
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
1 pass1 fail
Lead (PB90)
0 mg/L
Reported Dec 31, 2025
Copper (CU90)
2.13 mg/L
Reported Dec 31, 2007
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0
EPA limit 0.015
Copper (90th percentile)
Measured in mg/L
Local 2.13
EPA limit 1.3
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 27
- Health-based
- 0
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Consumer Confidence Rule | MT0003590 | Unaddressed | Oct 1, 2025 |
| Consumer Confidence Rule | MT0003590 | Unaddressed | Jul 1, 2025 |
| Total Haloacetic Acids (HAA5) | MT0000235 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| TTHM | MT0000235 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| Lead and Copper Rule | MT0002514 | Resolved | Dec 30, 2024through Feb 12, 2025 |
| Consumer Confidence Rule | MT0003590 | Unaddressed | Oct 1, 2024 |
| Lead and Copper Rule | MT0003590 | Unaddressed | Oct 1, 2024 |
| Consumer Confidence Rule | MT0003590 | Unaddressed | Jul 1, 2024 |
| Consumer Confidence Rule | MT0003590 | Unaddressed | Oct 1, 2023 |
| Revised Total Coliform Rule | MT0003590 | Resolved | Aug 1, 2023through Aug 31, 2023 |
| Consumer Confidence Rule | MT0002514 | Resolved | Jul 1, 2023through Jul 10, 2023 |
| Consumer Confidence Rule | MT0003590 | Unaddressed | Jul 1, 2023 |
| Revised Total Coliform Rule | MT0003590 | Resolved | Feb 1, 2023through Feb 28, 2023 |
| Revised Total Coliform Rule | MT0003590 | Resolved | May 1, 2022through May 31, 2022 |
| Lead and Copper Rule | MT0003590 | Resolved | Dec 30, 2021through Jan 18, 2022 |
| Consumer Confidence Rule | MT0003590 | Resolved | Oct 1, 2021through Nov 8, 2021 |
| Consumer Confidence Rule | MT0003590 | Resolved | Jul 1, 2021through Nov 8, 2021 |
| Revised Total Coliform Rule | MT0003590 | Resolved | Jun 1, 2021through Jun 30, 2021 |
| Revised Total Coliform Rule | MT0003590 | Resolved | May 1, 2021through May 31, 2021 |
| Revised Total Coliform Rule | MT0003590 | Resolved | Apr 1, 2021through Apr 30, 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
Your personalized water action plan
Matched to Hardin ZIP 59034 using 259.5 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
259.5 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
Under-Sink Reverse Osmosis System
Copper (90th percentile) has 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
Water questions for Hardin
Is tap water safe in Hardin?+
EPA ECHO shows no active health-based violation for the associated systems in this reporting snapshot. This does not prove every contaminant is absent; federal records can lag and household plumbing can change tap conditions.
How hard is the water?+
Nearby USGS observations produce an estimate of 259.5 PPM, or 15.2 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 259.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.