Hardness
Very Hard
368.5 PPM · 21.5 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 Stephenson County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
368.5 PPM · 21.5 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0.002 mg/L
13% of action level
Utility match
1 system
Serves 663 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
368.5 PPM
Parts per million
368.5
mg/L as CaCO₃ equivalent
Grains per gallon
21.5
1 GPG ≈ 17.1 PPM
What this means at home
At 368.5 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
62
Nearest site
14.8 mi
Observation range
Aug 3, 2016–May 27, 2021
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 27N10E-29.1d1 (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.
Cedarville median
369 PPM
About the same1 indexed ZIP readings · Range 368.5–368.5 PPM
Illinois median
285 PPM
84 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)
0.002 mg/L
Reported Jun 30, 2026
Copper (CU90)
1.38 mg/L
Reported Dec 31, 2025
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 0.002
EPA limit 0.015
Measured in mg/L
Local 1.38
EPA limit 1.3
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Total Haloacetic Acids (HAA5) | IL1770050 | Resolved | Jan 1, 2024through Dec 31, 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 Cedarville ZIP 61013 using 368.5 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
368.5 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 systemsDrinking water protection
Copper (90th percentile) 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 368.5 PPM, or 21.5 grains per gallon, classified as very hard. This is not a household tap measurement.
At 368.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.