Hardness
Hard
155 PPM · 9.1 GPG
Local water dashboard
Official source aggregationWater quality in Carbondale, IL 62902
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.
No active health-based violation reported
- Primary matched system
- Carbondale
- Source water
- Surface water
- County
- Williamson County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0.0023 mg/L
15% of action level
Utility match
3 systems
Serves 22,107 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
155 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
155
mg/L as CaCO₃ equivalent
Grains per gallon
9.1
1 GPG ≈ 17.1 PPM
What this means at home
At 155 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
7
Nearest site
34.3 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 62902 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Carbondale median
165 PPM
10 PPM lower3 indexed ZIP readings · Range 155–177 PPM
Illinois median
285 PPM
130 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)
0.0023 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.
Lead (90th percentile)
Measured in mg/L
Local 0.0023
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 17
- Health-based
- 7
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Long Term 2 Enhanced Surface Water Treatment RuleHealth-based | IL0770150 | Archived | Dec 1, 2025through Dec 31, 2025 |
| Long Term 2 Enhanced Surface Water Treatment RuleHealth-based | IL0775410 | Archived | Dec 1, 2025through Dec 31, 2025 |
| Lead and Copper Rule | IL0775410 | Unaddressed | Oct 1, 2025 |
| LEAD AND COPPER RULE REVISIONS | IL0775160 | Unaddressed | Jul 2, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | IL0775160 | Resolved | Oct 17, 2024through Jul 14, 2025 |
| Public Notice | IL0775410 | Resolved | Oct 7, 2024through Oct 8, 2024 |
| Public Notice | IL0770150 | Resolved | Aug 27, 2024through Aug 30, 2024 |
| CARBON, TOTAL | IL0770150 | Resolved | Jul 1, 2024through Sep 10, 2024 |
| CARBON, TOTALHealth-basedReported 0.73 RATIO | IL0770150 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| CARBON, TOTAL | IL0770150 | Resolved | Jul 1, 2024through Sep 10, 2024 |
| Consumer Confidence Rule | IL0775160 | Resolved | Jul 1, 2024through Aug 8, 2024 |
| CARBON, TOTALHealth-based | IL0775410 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| CARBON, TOTALHealth-basedReported 0.99 RATIO | IL0770150 | Resolved | Apr 1, 2024through Jun 30, 2024 |
| CARBON, TOTALHealth-basedReported 0.99 RATIO | IL0775410 | Resolved | Apr 1, 2024through Jun 30, 2024 |
| TTHM | IL0775410 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| Total Haloacetic Acids (HAA5) | IL0775410 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| Consumer Confidence Rule | IL0775410 | Resolved | Jul 1, 2023through Aug 14, 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 Carbondale ZIP 62902 using 155 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
155 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 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.
Nearby indexed reports
Compare ZIPs in Carbondale
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
Water questions for Carbondale
Is tap water safe in Carbondale?+
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.
How hard is the water?+
Nearby USGS observations produce an estimate of 155 PPM, or 9.1 grains per gallon, classified as hard. This is not a household tap measurement.
Do I need a water softener?+
At 155 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.