Hardness
Very Hard
349.5 PPM · 20.4 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 Hamilton County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
349.5 PPM · 20.4 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
5 systems
Serves 45,575 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
349.5 PPM
Parts per million
349.5
mg/L as CaCO₃ equivalent
Grains per gallon
20.4
1 GPG ≈ 17.1 PPM
What this means at home
At 349.5 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
36
Nearest site
9.8 mi
Observation range
Mar 30, 2016–Sep 10, 2025
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: NAWQA AG WELL TP3 AT SHERIDAN, IN (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.
Noblesville median
349 PPM
About the same2 indexed ZIP readings · Range 349–349.5 PPM
Indiana median
313 PPM
37 PPM higher472 indexed ZIP readings · Range 132–371 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 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.
Measured in mg/L
Local 0
EPA limit 0.015
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Consumer Confidence Rule | IN5229003 | Resolved | Oct 1, 2025through Jan 2, 2026 |
| Revised Total Coliform Rule | IN5229011 | Resolved | Oct 1, 2025through Oct 31, 2025 |
| Consumer Confidence Rule | IN5229003 | Resolved | Jul 1, 2025through Jan 2, 2026 |
| Consumer Confidence Rule | IN5229011 | Resolved | Jul 1, 2025through Oct 21, 2025 |
| Consumer Confidence Rule | IN5229012 | Resolved | Oct 7, 2024through Dec 18, 2024 |
| Lead and Copper Rule | IN5229011 | Resolved | Jan 1, 2024through Sep 16, 2025 |
| Lead and Copper RuleHealth-based | IN5229011 | Resolved | Apr 20, 2023through May 3, 2023 |
| Lead and Copper RuleHealth-based | IN5229011 | Resolved | Apr 20, 2023through May 3, 2023 |
| Lead and Copper Rule | IN5229011 | Resolved | Apr 20, 2023through Oct 3, 2023 |
| Consumer Confidence Rule | IN5229012 | Resolved | Jan 1, 2023through Nov 27, 2023 |
| Lead and Copper Rule | IN5229011 | Resolved | Oct 1, 2022through Oct 21, 2022 |
| Lead and Copper Rule | IN5229012 | Resolved | Jan 1, 2022through Nov 4, 2024 |
| Lead and Copper Rule | IN5229011 | Resolved | Jan 1, 2022through Dec 31, 2022 |
| Revised Total Coliform RuleHealth-based | IN5229012 | Resolved | Sep 1, 2021through Sep 30, 2021 |
| Revised Total Coliform Rule | IN5229003 | Resolved | Aug 1, 2021through Aug 31, 2021 |
| Revised Total Coliform Rule | IN5229003 | Resolved | Jul 1, 2021through Jul 31, 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
Matched to Noblesville ZIP 46062 using 349.5 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
349.5 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 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.
Nearby indexed reports
Estimates can differ across a city because monitoring locations and associated systems differ.
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 349.5 PPM, or 20.4 grains per gallon, classified as very hard. This is not a household tap measurement.
At 349.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.