Hardness
Very Hard
355 PPM · 20.8 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 Lewis County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
355 PPM · 20.8 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0.0018 mg/L
12% of action level
Utility match
1 system
Serves 875 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
355 PPM
Parts per million
355
mg/L as CaCO₃ equivalent
Grains per gallon
20.8
1 GPG ≈ 17.1 PPM
What this means at home
At 355 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
5
Nearest site
7.1 mi
Observation range
May 23, 2017–Aug 24, 2023
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 1S 9W-11.5h2 (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.
La Grange median
355 PPM
About the same1 indexed ZIP readings · Range 355–355 PPM
Missouri median
236 PPM
119 PPM higher556 indexed ZIP readings · Range 38.3–483 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)
0.0018 mg/L
Reported Dec 31, 2024
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 0.0018
EPA limit 0.015
Measured in UG/L
Local 83
EPA limit 0.08
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Public Notice | MO2010440 | Resolved | Jul 3, 2025through Aug 11, 2025 |
| LEAD AND COPPER RULE REVISIONS | MO2010440 | Unaddressed | Jul 2, 2025 |
| TTHMHealth-basedReported 83 UG/L · MCL 0.08 | MO2010440 | Resolved | Jan 1, 2025through Mar 31, 2025 |
| Groundwater Rule | MO2010440 | Resolved | Jan 1, 2025through Jan 31, 2025 |
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 La Grange ZIP 63448 using 355 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
355 PPM is 3× 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
TTHM 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
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 355 PPM, or 20.8 grains per gallon, classified as very hard. This is not a household tap measurement.
At 355 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.