Hardness
Very Hard
305 PPM · 17.8 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 Sangamon County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
305 PPM · 17.8 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
10 systems
Serves 117,444 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
305 PPM
Parts per million
305
mg/L as CaCO₃ equivalent
Grains per gallon
17.8
1 GPG ≈ 17.1 PPM
What this means at home
At 305 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
39.9 mi
Observation range
Jan 6, 2016–Jun 9, 2026
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: MASON TAZEWELL DRAINAGE D AT CR2350E NR TOPEKA, IL (Stream).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.
Springfield median
305 PPM
About the same8 indexed ZIP readings · Range 305–305 PPM
Illinois median
285 PPM
20 PPM higher1065 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 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 |
|---|---|---|---|
| Revised Total Coliform Rule | IL1670070 | Archived | Mar 1, 2026through Mar 31, 2026 |
| Chloramine | IL1670070 | Archived | Mar 1, 2026through Mar 31, 2026 |
| Total Haloacetic Acids (HAA5) | IL1670090 | Archived | Oct 1, 2025through Dec 31, 2025 |
| Atrazine | IL1671200 | Resolved | Jul 1, 2025through Sep 30, 2025 |
| Consumer Confidence Rule | IL1670070 | Unaddressed | Jul 1, 2025 |
| Consumer Confidence Rule | IL1670160 | Unaddressed | Jul 1, 2025 |
| Consumer Confidence Rule | IL1670110 | Unaddressed | Jul 1, 2025 |
| Consumer Confidence Rule | IL1670140 | Unaddressed | Jul 1, 2025 |
| Total Haloacetic Acids (HAA5) | IL1670070 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| TTHM | IL1670070 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| TTHM | IL1670090 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| Total Haloacetic Acids (HAA5) | IL1670090 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| Chloramine | IL1670070 | Resolved | Feb 1, 2025through Feb 28, 2025 |
| Revised Total Coliform Rule | IL1670070 | Resolved | Feb 1, 2025through Feb 28, 2025 |
| TTHM | IL1671200 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| Total Haloacetic Acids (HAA5) | IL1671200 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| TTHM | IL1670070 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| Total Haloacetic Acids (HAA5) | IL1670070 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| Lead and Copper RuleHealth-based | IL1670110 | Resolved | Apr 2, 2024through Jun 5, 2025 |
| Lead and Copper RuleHealth-based | IL1670140 | Resolved | Apr 2, 2024through Jul 2, 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 Springfield ZIP 62711 using 305 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
305 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 305 PPM, or 17.8 grains per gallon, classified as very hard. This is not a household tap measurement.
At 305 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.