Hardness
Hard
180 PPM · 10.5 GPG
Local water dashboard
Official source aggregationWater quality in Shell Knob, MO 65747
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Stone County.
No active health-based violation reported
- Primary matched system
- Mo American Ozark Mtn Water Company 2
- Source water
- Groundwater
- County
- Stone 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
0.007 mg/L
47% of action level
Utility match
8 systems
Serves 583 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
180 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
180
mg/L as CaCO₃ equivalent
Grains per gallon
10.5
1 GPG ≈ 17.1 PPM
What this means at home
At 180 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
49
Nearest site
14.1 mi
Observation range
May 4, 2016–Sep 4, 2025
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: Roaring River Spring at Cassville, MO (Spring).USGS source documentation ↗
Regional context
Is 65747 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Shell Knob median
180 PPM
About the same1 indexed ZIP readings · Range 180–180 PPM
Missouri median
236 PPM
56 PPM lower556 indexed ZIP readings · Range 38.3–483 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 pass
Lead (PB90)
0.007 mg/L
Reported Dec 31, 2025
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
1 comparable result
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0.007
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 14
- Health-based
- 0
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Lead and Copper Rule | MO5036197 | Unaddressed | Dec 30, 2025 |
| Lead and Copper Rule | MO5036253 | Unaddressed | Dec 30, 2025 |
| Lead and Copper Rule | MO5036168 | Unaddressed | Dec 30, 2025 |
| Lead and Copper Rule | MO5036196 | Unaddressed | Dec 30, 2025 |
| Public Notice | MO5036196 | Resolved | Jul 31, 2025through Jun 15, 2025 |
| LEAD AND COPPER RULE REVISIONS | MO5036182 | Unaddressed | Jul 2, 2025 |
| LEAD AND COPPER RULE REVISIONS | MO5036168 | Unaddressed | Jul 2, 2025 |
| LEAD AND COPPER RULE REVISIONS | MO5036253 | Resolved | Oct 17, 2024through Jan 12, 2025 |
| Revised Total Coliform Rule | MO5036182 | Resolved | Jul 1, 2024through Jul 31, 2024 |
| Consumer Confidence Rule | MO5036196 | Resolved | Jul 1, 2024through Aug 15, 2024 |
| Revised Total Coliform Rule | MO5036196 | Resolved | Jun 1, 2024through Jun 30, 2024 |
| Revised Total Coliform Rule | MO5036168 | Resolved | Jan 1, 2024through Jan 31, 2024 |
| Lead and Copper Rule | MO5036182 | Resolved | Dec 30, 2023through Jul 30, 2024 |
| Revised Total Coliform Rule | MO5036168 | Resolved | Dec 1, 2023through Dec 31, 2023 |
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 Shell Knob ZIP 65747 using 180 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
180 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 systemsAffiliate 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 Shell Knob
Is tap water safe in Shell Knob?+
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 180 PPM, or 10.5 grains per gallon, classified as hard. This is not a household tap measurement.
Do I need a water softener?+
At 180 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.