Hardness
Very Hard
371 PPM · 21.7 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 Ogle County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
371 PPM · 21.7 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0.0012 mg/L
8% of action level
Utility match
1 system
Serves 1,338 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
371 PPM
Parts per million
371
mg/L as CaCO₃ equivalent
Grains per gallon
21.7
1 GPG ≈ 17.1 PPM
What this means at home
At 371 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
65
Nearest site
12.5 mi
Observation range
May 30, 2017–May 27, 2021
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 24N 6E- 5.5e1 (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.
Forreston median
371 PPM
About the same1 indexed ZIP readings · Range 371–371 PPM
Illinois median
285 PPM
86 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)
0.0012 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 0.0012
EPA limit 0.015
100% line = listed limit
No violation record was returned for the associated systems in the imported lookback window beginning Jan 1, 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 Forreston ZIP 61030 using 371 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
371 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.
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 371 PPM, or 21.7 grains per gallon, classified as very hard. This is not a household tap measurement.
At 371 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.