Hardness
Hard
164.5 PPM · 9.6 GPG
Local water dashboard
Official source aggregationWater quality in Carterville, IL 62918
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
- Carterville
- 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 mg/L
0% of action level
Utility match
3 systems
Serves 6,528 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 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 62918 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Carterville 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, 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
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 19
- Health-based
- 3
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| TTHM | IL1995350 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Total Haloacetic Acids (HAA5) | IL1995350 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Long Term 2 Enhanced Surface Water Treatment RuleHealth-based | IL1995350 | Archived | Dec 1, 2025through Dec 31, 2025 |
| Lead and Copper Rule | IL1995350 | Unaddressed | Oct 1, 2025 |
| TTHM | IL1990150 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| Total Haloacetic Acids (HAA5) | IL1990150 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| Public Notice | IL1995350 | Resolved | Jan 31, 2025through Sep 1, 2024 |
| Public Notice | IL1995350 | Resolved | Oct 7, 2024through Jun 4, 2025 |
| Consumer Confidence Rule | IL1990150 | Resolved | Jul 1, 2024through Jun 27, 2025 |
| CARBON, TOTALHealth-based | IL1995350 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| CARBON, TOTALHealth-basedReported 0.99 RATIO | IL1995350 | Resolved | Apr 1, 2024through Jun 30, 2024 |
| Consumer Confidence Rule | IL1995350 | Resolved | Jul 1, 2023through Feb 23, 2024 |
| Total Haloacetic Acids (HAA5) | IL1995350 | Resolved | Apr 1, 2023through Jun 30, 2023 |
| Chloramine | IL1990150 | Resolved | Oct 1, 2022through Nov 28, 2022 |
| Revised Total Coliform Rule | IL1990150 | Resolved | Oct 1, 2022through Oct 31, 2022 |
| TTHM | IL1990150 | Resolved | Mar 1, 2022through May 31, 2022 |
| Total Haloacetic Acids (HAA5) | IL1990150 | Resolved | Mar 1, 2022through May 31, 2022 |
| Consumer Confidence Rule | IL1995350 | Resolved | Jul 1, 2021through Oct 12, 2021 |
| Consumer Confidence Rule | IL1990120 | Resolved | Jul 1, 2021through Jul 1, 2022 |
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 Carterville ZIP 62918 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 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
Water questions for Carterville
Is tap water safe in Carterville?+
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 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.