Hardness
Hard
138 PPM · 8.1 GPG
Local water dashboard
Official source aggregationWater quality in Missoula, MT 59803
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Missoula County.
3 active health-based violations
- Primary matched system
- Missoula Water
- Source water
- Groundwater
- County
- Missoula County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
Review needed
3 active health-based records
Lead 90th percentile
0.003 mg/L
20% of action level
Utility match
10 systems
Serves 68,200 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
138 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
138
mg/L as CaCO₃ equivalent
Grains per gallon
8.1
1 GPG ≈ 17.1 PPM
What this means at home
At 138 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
32
Nearest site
6.4 mi
Observation range
Mar 4, 2016–May 6, 2026
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: Clark Fork above Missoula MT (Stream).USGS source documentation ↗
Regional context
Is 59803 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Missoula median
152 PPM
14 PPM lower5 indexed ZIP readings · Range 101.6–152 PPM
Montana median
122 PPM
16 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)
0.003 mg/L
Reported Dec 31, 2027
Copper (CU90)
1.87 mg/L
Reported Dec 31, 2022
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0.003
EPA limit 0.015
Copper (90th percentile)
Measured in mg/L
Local 1.87
EPA limit 1.3
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 199
- Health-based
- 16
- Active health-based
- 3
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Revised Total Coliform Rule | MT0000453 | Resolved | Mar 1, 2026through Mar 31, 2026 |
| Lead and Copper Rule | MT0000450 | Unaddressed | Oct 1, 2025 |
| Lead and Copper Rule | MT0003215 | Unaddressed | Oct 1, 2025 |
| Lead and Copper Rule | MT0003012 | Unaddressed | Oct 1, 2025 |
| Lead and Copper Rule | MT0004074 | Unaddressed | Oct 1, 2025 |
| Revised Total Coliform RuleHealth-based | MT0002517 | Resolved | Jul 1, 2025through Nov 17, 2025 |
| Consumer Confidence Rule | MT0004368 | Resolved | Jul 1, 2025through Jul 17, 2025 |
| Consumer Confidence Rule | MT0003565 | Resolved | Jul 1, 2025through Jul 24, 2025 |
| Nitrate-Nitrite | MT0005006 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| Revised Total Coliform Rule | MT0000367 | Resolved | Mar 1, 2025through Mar 31, 2025 |
| Lead and Copper Rule | MT0004107 | Resolved | Dec 30, 2024through Mar 17, 2025 |
| Lead and Copper Rule | MT0004322 | Resolved | Dec 30, 2024through Mar 4, 2025 |
| Lead and Copper Rule | MT0000377 | Resolved | Dec 30, 2024through Nov 14, 2025 |
| Lead and Copper Rule | MT0005006 | Resolved | Dec 30, 2024through Jun 19, 2025 |
| Lead and Copper Rule | MT0002517 | Unaddressed | Oct 1, 2024 |
| Lead and Copper Rule | MT0002635 | Resolved | Oct 1, 2024through Sep 29, 2025 |
| Groundwater RuleHealth-based | MT0000368 | Resolved | Oct 1, 2024through Oct 31, 2024 |
| Revised Total Coliform Rule | MT0002635 | Resolved | Jul 1, 2024through Jul 31, 2024 |
| Groundwater RuleHealth-based | MT0000368 | Resolved | Jul 1, 2024through Jul 31, 2024 |
| Consumer Confidence Rule | MT0004368 | Resolved | Jul 1, 2024through Sep 4, 2024 |
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 Missoula ZIP 59803 using 138 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
138 PPM is 1× 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.
Nearby indexed reports
Compare ZIPs in Missoula
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
Water questions for Missoula
Is tap water safe in Missoula?+
EPA ECHO reports 3 active health-based violations among the associated community water systems. Review the affected utility's current notice and Consumer Confidence Report.
How hard is the water?+
Nearby USGS observations produce an estimate of 138 PPM, or 8.1 grains per gallon, classified as hard. This is not a household tap measurement.
Do I need a water softener?+
At 138 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.