Hardness
Very Hard
283.5 PPM · 16.6 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 Iroquois County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
283.5 PPM · 16.6 GPG
Compliance screen
Review needed
1 active health-based record
Lead 90th percentile
0 mg/L
0% of action level
Utility match
2 systems
Serves 550 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
283.5 PPM
Parts per million
283.5
mg/L as CaCO₃ equivalent
Grains per gallon
16.6
1 GPG ≈ 17.1 PPM
What this means at home
At 283.5 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
70
Nearest site
22.9 mi
Observation range
May 30, 2017–Aug 22, 2023
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 29N11W-6.7b (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.
Danforth median
284 PPM
About the same1 indexed ZIP readings · Range 283.5–283.5 PPM
Illinois median
285 PPM
About the same1065 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, 2024
Copper (CU90)
1.46 mg/L
Reported Mar 31, 1994
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 0
EPA limit 0.015
Measured in mg/L
Local 1.46
EPA limit 1.3
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| TTHM | IL0750020 | Resolved | Jul 1, 2025through Sep 30, 2025 |
| Total Haloacetic Acids (HAA5) | IL0750020 | Resolved | Jul 1, 2025through Sep 30, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | IL0750350 | Unaddressed | Oct 17, 2024 |
| Consumer Confidence Rule | IL0750020 | Resolved | Jul 1, 2024through Jun 27, 2025 |
| Consumer Confidence Rule | IL0750020 | Resolved | Jul 1, 2023through Jun 27, 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 Danforth ZIP 60930 using 283.5 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
283.5 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 systemsDrinking water protection
Copper (90th percentile), LEAD AND COPPER RULE REVISIONS have 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 reports 1 active health-based violation among the associated community water systems. Review the affected utility's current notice and Consumer Confidence Report.
Nearby USGS observations produce an estimate of 283.5 PPM, or 16.6 grains per gallon, classified as very hard. This is not a household tap measurement.
At 283.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.