Hardness
Very Hard
320.5 PPM · 18.7 GPG
Local water dashboard
Official source aggregationWater quality in Dover, IL 61323
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Bureau County.
1 active health-based violation
- Primary matched system
- Dover
- Source water
- Groundwater
- County
- Bureau County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
Review needed
1 active health-based record
Lead 90th percentile
3.0e-4 mg/L
2% of action level
Utility match
1 system
Serves 200 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
320.5 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
320.5
mg/L as CaCO₃ equivalent
Grains per gallon
18.7
1 GPG ≈ 17.1 PPM
What this means at home
At 320.5 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
36
Nearest site
21.3 mi
Observation range
May 22, 2017–Aug 21, 2023
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 33N 2E- 9.7b1 (Well).USGS source documentation ↗
Regional context
Is 61323 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Dover median
321 PPM
About the same1 indexed ZIP readings · Range 320.5–320.5 PPM
Illinois median
285 PPM
36 PPM higher1065 indexed ZIP readings · Range 115–408 PPM
EPA benchmark screen
Contaminant snapshot
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
1 pass1 fail
Lead (PB90)
3.0e-4 mg/L
Reported Dec 31, 2024
Copper (CU90)
1.818 mg/L
Reported Jun 30, 2009
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 3.0e-4
EPA limit 0.015
Copper (90th percentile)
Measured in mg/L
Local 1.818
EPA limit 1.3
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 4
- Health-based
- 1
- Active health-based
- 1
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Public Notice | IL0110350 | Unaddressed | Aug 22, 2025 |
| LEAD AND COPPER RULE REVISIONS | IL0110350 | Unaddressed | Jul 2, 2025 |
| LEAD AND COPPER RULE REVISIONS | IL0110350 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONSHealth-based | IL0110350 | Unaddressed | Oct 17, 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
Your personalized water action plan
Matched to Dover ZIP 61323 using 320.5 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
320.5 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
Under-Sink Reverse Osmosis System
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
Water questions for Dover
Is tap water safe in Dover?+
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.
How hard is the water?+
Nearby USGS observations produce an estimate of 320.5 PPM, or 18.7 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 320.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.