Hardness
Very Hard
336 PPM · 19.6 GPG
Local water dashboard
Official source aggregationWater quality in Terre Haute, IN 47803
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Vigo County.
1 active health-based violation
- Primary matched system
- Indiana American Water - Terre Haute
- Source water
- Groundwater
- County
- Vigo 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
0.002 mg/L
13% of action level
Utility match
7 systems
Serves 67,765 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
336 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
336
mg/L as CaCO₃ equivalent
Grains per gallon
19.6
1 GPG ≈ 17.1 PPM
What this means at home
At 336 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
15
Nearest site
28.2 mi
Observation range
Mar 30, 2016–Sep 2, 2025
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: NAWQA AG WELL TP15 AT MORTON, IN (Well).USGS source documentation ↗
Regional context
Is 47803 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Terre Haute median
337 PPM
About the same5 indexed ZIP readings · Range 336–337 PPM
Indiana median
313 PPM
23 PPM higher472 indexed ZIP readings · Range 132–371 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)
0.002 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 0.002
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 51
- Health-based
- 2
- Active health-based
- 1
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Public Notice | IN5284022 | Unaddressed | Dec 2, 2025 |
| Consumer Confidence Rule | IN5284027 | Unaddressed | Oct 1, 2025 |
| Gross Alpha, Excl. Radon and U | IN5284019 | Archived | Oct 1, 2025through Dec 31, 2025 |
| Radium-228 | IN5284019 | Archived | Oct 1, 2025through Dec 31, 2025 |
| Consumer Confidence Rule | IN5284019 | Unaddressed | Oct 1, 2025 |
| Radium-226 | IN5284019 | Archived | Oct 1, 2025through Dec 31, 2025 |
| Consumer Confidence Rule | IN5284018 | Resolved | Jul 1, 2025through Oct 29, 2025 |
| Consumer Confidence Rule | IN5284027 | Unaddressed | Jul 1, 2025 |
| Consumer Confidence Rule | IN5284019 | Unaddressed | Jul 1, 2025 |
| Public Notice | IN5284022 | Unaddressed | Jan 1, 2025 |
| Nitrate | IN5284022 | Resolved | Jan 1, 2025through Dec 31, 2025 |
| Nitrate | IN5284019 | Archived | Jan 1, 2025through Dec 31, 2025 |
| LEAD AND COPPER RULE REVISIONS | IN5284022 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONSHealth-based | IN5284022 | Unaddressed | Oct 17, 2024 |
| Consumer Confidence Rule | IN5284019 | Unaddressed | Oct 10, 2024 |
| Consumer Confidence Rule | IN5284019 | Unaddressed | Jul 1, 2024 |
| Lead and Copper Rule | IN5284027 | Unaddressed | Jan 1, 2024 |
| cis-1,2-Dichloroethylene | IN5284019 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| DICHLOROMETHANE | IN5284019 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| p-Dichlorobenzene | IN5284019 | Resolved | Jan 1, 2024through Dec 31, 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 Terre Haute ZIP 47803 using 336 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
336 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
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.
Nearby indexed reports
Compare ZIPs in Terre Haute
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
Water questions for Terre Haute
Is tap water safe in Terre Haute?+
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 336 PPM, or 19.6 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 336 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.