Hardness
Hard
164.5 PPM · 9.6 GPG
Local water dashboard
Official source aggregationWater quality in Colp, IL 62921
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Williamson County.
1 active health-based violation
- Primary matched system
- Colp
- Source water
- Surface water
- County
- Williamson 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
0 mg/L
0% of action level
Utility match
1 system
Serves 506 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
164.5 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
164.5
mg/L as CaCO₃ equivalent
Grains per gallon
9.6
1 GPG ≈ 17.1 PPM
What this means at home
At 164.5 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
6
Nearest site
42.8 mi
Observation range
Jan 4, 2016–May 28, 2026
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: OHIO RIVER AT OLMSTED, IL (Stream).USGS source documentation ↗
Regional context
Is 62921 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Colp median
165 PPM
About the same1 indexed ZIP readings · Range 164.5–164.5 PPM
Illinois median
285 PPM
120 PPM lower1065 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 pass
Lead (PB90)
0 mg/L
Reported Dec 31, 2023
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.
Lead (90th percentile)
Measured in mg/L
Local 0
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 6
- Health-based
- 1
- Active health-based
- 1
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| LEAD AND COPPER RULE REVISIONS | IL1990200 | Unaddressed | Jul 2, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | IL1990200 | Unaddressed | Oct 17, 2024 |
| Public Notice | IL1990200 | Resolved | Jul 11, 2024through Jun 1, 2023 |
| Consumer Confidence Rule | IL1990200 | Resolved | Jul 1, 2024through Jul 1, 2025 |
| Consumer Confidence Rule | IL1990200 | Resolved | Jul 1, 2023through Jul 1, 2025 |
| Total Haloacetic Acids (HAA5) | IL1990200 | Resolved | Apr 1, 2023through Jun 30, 2023 |
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 Colp ZIP 62921 using 164.5 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
164.5 PPM is 1× 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
LEAD AND COPPER RULE REVISIONS 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
Water questions for Colp
Is tap water safe in Colp?+
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 164.5 PPM, or 9.6 grains per gallon, classified as hard. This is not a household tap measurement.
Do I need a water softener?+
At 164.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.