Hardness
Very Hard
264.5 PPM · 15.5 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 Madison County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
264.5 PPM · 15.5 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
3 systems
Serves 26,808 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
264.5 PPM
Parts per million
264.5
mg/L as CaCO₃ equivalent
Grains per gallon
15.5
1 GPG ≈ 17.1 PPM
What this means at home
At 264.5 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
6
Nearest site
8.8 mi
Observation range
Jun 2, 2016–Aug 23, 2023
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 3N 8W-31.1a3 (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.
Edwardsville median
267 PPM
About the same2 indexed ZIP readings · Range 264.5–269 PPM
Illinois median
285 PPM
20 PPM lower1065 indexed ZIP readings · Range 115–408 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, 2026
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 |
|---|---|---|---|
| Total Haloacetic Acids (HAA5) | IL1190270 | Archived | Jan 1, 2026through Mar 31, 2026 |
| TTHM | IL1190270 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Lead and Copper Rule | IL1190260 | Resolved | Oct 1, 2025through Sep 25, 2025 |
| TTHM | IL1190270 | Archived | Oct 1, 2025through Dec 31, 2025 |
| Total Haloacetic Acids (HAA5) | IL1190270 | Archived | Oct 1, 2025through Dec 31, 2025 |
| Consumer Confidence Rule | IL1190250 | Resolved | Jul 1, 2025through Nov 18, 2025 |
| TTHM | IL1190270 | Archived | Jul 1, 2025through Sep 30, 2025 |
| Total Haloacetic Acids (HAA5) | IL1190270 | Archived | Jul 1, 2025through Sep 30, 2025 |
| Lead and Copper Rule | IL1190270 | Unaddressed | Jul 1, 2025 |
| Lead and Copper Rule | IL1190270 | Unaddressed | Apr 1, 2025 |
| TTHM | IL1190270 | Resolved | Jan 1, 2025through Mar 31, 2025 |
| Total Haloacetic Acids (HAA5) | IL1190270 | Resolved | Jan 1, 2025through Mar 31, 2025 |
| TTHM | IL1190270 | Resolved | Oct 1, 2024through Dec 31, 2024 |
| Total Haloacetic Acids (HAA5) | IL1190270 | Resolved | Oct 1, 2024through Dec 31, 2024 |
| TTHM | IL1190270 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| Total Haloacetic Acids (HAA5) | IL1190270 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| Lead and Copper Rule | IL1190260 | Resolved | Oct 1, 2022through Feb 29, 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
Matched to Edwardsville ZIP 62026 using 264.5 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
264.5 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.
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 264.5 PPM, or 15.5 grains per gallon, classified as very hard. This is not a household tap measurement.
At 264.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.