Hardness
Soft
37.7 PPM · 2.2 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 Jefferson County.
At a glance
EPA quarter 2026Q2
Hardness
Soft
37.7 PPM · 2.2 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
1 system
Serves 200 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
37.7 PPM
Parts per million
37.7
mg/L as CaCO₃ equivalent
Grains per gallon
2.2
1 GPG ≈ 17.1 PPM
What this means at home
At 37.7 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
9
Nearest site
10 mi
Observation range
Jun 9, 2016–Sep 14, 2017
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 08N06W25ADAC02 (Well).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.
Basin median
38 PPM
About the same1 indexed ZIP readings · Range 37.7–37.7 PPM
Montana median
122 PPM
84 PPM lower129 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 mg/L
Reported Jun 30, 2025
Copper (CU90)
1.76 mg/L
Reported Jun 30, 2016
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 0
EPA limit 0.015
Measured in mg/L
Local 1.76
EPA limit 1.3
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Lead and Copper Rule | MT0000014 | Resolved | Oct 1, 2023through Feb 13, 2024 |
| Consumer Confidence Rule | MT0000014 | Resolved | Jul 1, 2023through Jul 5, 2023 |
| Lead and Copper Rule | MT0000014 | Resolved | Jul 1, 2023through Mar 17, 2025 |
| Lead and Copper Rule | MT0000014 | Resolved | Sep 29, 2022through Feb 26, 2024 |
| Consumer Confidence Rule | MT0000014 | Resolved | Jul 1, 2022through Aug 16, 2022 |
| Lead and Copper Rule | MT0000014 | Resolved | Apr 1, 2022through Feb 26, 2024 |
| Lead and Copper RuleHealth-based | MT0000014 | Resolved | Feb 8, 2021through Nov 13, 2023 |
| Nitrate-Nitrite | MT0000014 | Resolved | Jan 1, 2021through Dec 31, 2021 |
| Lead and Copper Rule | MT0000014 | Addressed | Dec 30, 2014 |
| Lead and Copper Rule | MT0000014 | Addressed | Jan 1, 2014 |
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 Basin ZIP 59631 using 37.7 PPM nearby hardness and 2 reported measurement benchmarks.
Drinking water protection
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.
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Frequently asked
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.
Nearby USGS observations produce an estimate of 37.7 PPM, or 2.2 grains per gallon, classified as soft. This is not a household tap measurement.
There is no high-hardness trigger in this profile. Confirm with a tap test before buying equipment.