Hardness
Very Hard
310.5 PPM · 18.2 GPG
Local water dashboard
Official source aggregationWater quality in Assumption, IL 62510
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Christian County.
1 reported benchmark flag
- Primary matched system
- Assumption
- Source water
- Groundwater
- County
- Christian 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
1 system
Serves 1,315 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
310.5 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
310.5
mg/L as CaCO₃ equivalent
Grains per gallon
18.2
1 GPG ≈ 17.1 PPM
What this means at home
At 310.5 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
30
Nearest site
34 mi
Observation range
May 1, 2018–Jul 30, 2025
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 18N 3E-18.6a (Well).USGS source documentation ↗
Regional context
Is 62510 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Assumption median
311 PPM
About the same1 indexed ZIP readings · Range 310.5–310.5 PPM
Illinois median
285 PPM
26 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)
0 mg/L
Reported Dec 31, 2024
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0
EPA limit 0.015
TTHM
Measured in MG/L
Local 0.081
EPA limit 0.08
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 18
- Health-based
- 3
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| TTHM | IL0210050 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Total Haloacetic Acids (HAA5) | IL0210050 | Archived | Jan 1, 2026through Mar 31, 2026 |
| TTHM | IL0210050 | Unaddressed | Dec 18, 2025 |
| Public Notice | IL0210050 | Unaddressed | Oct 13, 2025 |
| Public Notice | IL0210050 | Unaddressed | Oct 13, 2025 |
| Public Notice | IL0210050 | Unaddressed | Oct 13, 2025 |
| Public Notice | IL0210050 | Unaddressed | Aug 22, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | IL0210050 | Resolved | Oct 17, 2024through Dec 4, 2025 |
| LEAD AND COPPER RULE REVISIONS | IL0210050 | Resolved | Oct 17, 2024through Dec 4, 2025 |
| TTHMHealth-basedReported 0.081 MG/L · MCL 0.08 | IL0210050 | Resolved | Oct 1, 2024through Dec 31, 2024 |
| Nitrate | IL0210050 | Resolved | Sep 1, 2024through Sep 30, 2024 |
| Nitrate | IL0210050 | Resolved | Sep 1, 2024through Sep 30, 2024 |
| Nitrate | IL0210050 | Resolved | Sep 1, 2024through Sep 30, 2024 |
| Public Notice | IL0210050 | Resolved | Jul 12, 2024through Dec 4, 2025 |
| TTHMHealth-basedReported 0.091 MG/L · MCL 0.08 | IL0210050 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| TTHM | IL0210050 | Resolved | Jul 1, 2023through Sep 30, 2023 |
| Total Haloacetic Acids (HAA5) | IL0210050 | Resolved | Jul 1, 2023through Sep 30, 2023 |
| TTHM | IL0210050 | Resolved | Jun 21, 2023through Jan 24, 2025 |
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 Assumption ZIP 62510 using 310.5 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
310.5 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
TTHM 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 Assumption
Is tap water safe in Assumption?+
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 310.5 PPM, or 18.2 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 310.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.