Tap water report · updated November 2026
Indianapolis tap water: very hard water, no PFOA or PFOS found
What’s in the water Citizens Energy Group delivers to 880,345 people, from national testing by the U.S. Environmental Protection Agency (EPA) and the utility’s own report.
Short answer
Indianapolis tap water is very hard: about 18.5 grains per gallon (317 milligrams per liter (mg/L)), according to published water quality data from Citizens Energy Group (2025). The U.S. Environmental Protection Agency’s (EPA’s) 2023–24 testing found no PFOA or PFOS (two PFAS “forever chemicals”) at or above its 4 parts per trillion (ppt) limit. The system had no health-based violations in the five years through September 2026. Of the 40 large US water systems The Water Monitor tracks, Indianapolis has the hardest water.
Sources: Citizens Energy Group 2025 data, EPA UCMR 5, EPA SDWIS 2026Q3 · Sources and method
None found
every sample under 4 ppt
Under EPA’s 4 ppt limit
EPA UCMR 5, sampled 2023–24
How Indianapolis compares with the 40 systems we track
Hardness
1st hardest
of 34 systems
PFOA / PFOS
Not detected
in any EPA sample
Size
22nd largest
of 40 by people served
01 · What it means
What these readings mean for your home
Each reading in plain English: what it is, how Indianapolis compares with the other systems we track, and whether there’s anything to do. The tags follow EPA’s limits and reference levels where EPA has one; for hardness, which has no EPA limit, they follow the U.S. Geological Survey (USGS) scale and Minnesota’s health department. New to the acronyms? Every term, in plain English.
Hardness
Worth acting onHardness is dissolved calcium and magnesium, picked up as water runs through rock. It isn’t a health issue (EPA has no limit for it). It’s what leaves white crust on faucets, spots on glasses and scale inside your water heater. It’s measured in grains per gallon (gpg); 1 gpg is about 17 mg of minerals in a liter.
Here: At 18.5 gpg, Indianapolis water is very hard, the 1st-hardest of the 34 systems we track. You’ll see scale on fixtures and inside appliances.
What to do: A water softener is the only whole-house system that removes hardness. Size it to your household so it doesn’t waste salt.
What the research says: Studies tie hard water to more soap use and scale. Observational studies link it with somewhat more eczema in babies, but in the largest trial a softener didn’t improve existing eczema. The studies →
Learn more →PFAS (PFOA and PFOS)
Nothing to doPFAS are a family of thousands of manufactured chemicals used in many consumer and industrial products. They break down very slowly, which is why people call them "forever chemicals." PFOA and PFOS are the two EPA regulates most tightly. They’re measured in parts per trillion (ppt): 1 ppt is about one drop in 20 Olympic swimming pools.
Here: EPA’s 2023–24 testing found no PFOA or PFOS in Indianapolis’s water at or above 4 ppt, the lowest level labs can reliably measure. 29 of the 40 systems we track can say the same; 11 had a sample over the limit.
What to do: Nothing needed by EPA’s standard. If you want PFAS lower still, the same certified filters apply.
What the research says: EPA and the National Academies link PFOA and PFOS exposure to higher cholesterol, lower vaccine response, lower birth weight and some cancers, mostly over years of drinking the water. The studies →
Learn more →Disinfectant
Nothing to doUtilities add a small amount of chlorine, or chloramine (chlorine combined with a little ammonia), so germs can’t grow in the pipes on the way to your tap. EPA allows up to 4 milligrams per liter (mg/L) of either and says water within its standards can be used for drinking, cooking and bathing.
Here: Indianapolis uses chloramine, like 20 other systems we track. It lasts longer in pipes than chlorine and is harder to filter.
What to do: For taste, use catalytic carbon or a filter certified to NSF/ANSI 42 for chloramine. Fish tanks and home dialysis need it removed completely.
What the research says: Health agencies call these levels acceptable for drinking and bathing; dialysis and fish tanks are the exceptions. Studies haven’t shown shower chlorine harms skin or hair. The studies →
Learn more →Health-based violations
Nothing to doA health-based violation means the utility broke a federal drinking water rule tied to health: it went over a limit, or skipped a required treatment step. Missing a paperwork deadline doesn’t count.
Here: Indianapolis’s system had none in the five years through September 2026. That’s normal for a large system: 36 of the 40 we track had none.
What to do: Nothing to do.
Learn more →How Indianapolis compares: highest PFOA or PFOS sample
Parts per trillion (ppt), from EPA’s 2023–25 testing. The dashed line is EPA’s limit of 4.
Indianapolis: none at or above 4 ppt. Like 28 other systems we track, EPA’s testing found no PFOA or PFOS there. These 11 did:
- Miami33.0 PFOS
- El Paso8.5 PFOS
- Fort Worth8.3 PFOA
- Philadelphia8.1 PFOA
- Louisville7.5 PFOA
- Tampa6.9 PFOS
- Dallas6.3 PFOA
- San Jose6.2 PFOS
- Cincinnati6.1 PFOS
- Columbus5.3 PFOA
- Austin4.8 PFOS
If you live in Indianapolis
- Size a softener for Indianapolis water At 18.5 grains per gallon, the calculator works out the capacity for your household.
- What softeners cost Store and dealer prices, with what each includes.
- Whole-house filters for chloramine Indianapolis uses chloramine, which ordinary carbon removes slowly. What to look for and what it costs.
Indianapolis’s water is very hard. Softeners from brands that sell online, at their own store prices:
We may earn a commission from these links.
02 · The full results
Every PFAS result EPA recorded
EPA’s national testing (sampled 2023 to 2024) found no PFOA or PFOS at or above 4 ppt in any of 26 samples, which puts Indianapolis under EPA’s limit for both.
Results from EPA’s national testing program (UCMR 5) for Citizens Energy Group, 9 sampling points, August 2023 to August 2024. Concentrations in parts per trillion (ppt).
| Chemical | Samples | Detected | Highest | EPA limit |
|---|---|---|---|---|
| PFOA (perfluorooctanoic acid) | 26 | 0 | none | 4 |
| PFOS (perfluorooctane sulfonic acid) | 26 | 0 | none | 4 |
| PFHxS | 26 | 0 | none | 10 |
| PFNA | 26 | 0 | none | 10 |
| HFPO-DA (GenX) | 26 | 0 | none | 10 |
"None" means every sample was under EPA’s reporting level (4 ppt for PFOA). PFHxS, PFNA and HFPO-DA (GenX) are three other PFAS chemicals; EPA proposed removing their limits in May 2026, and that isn’t final.
03 · Where it comes from
The source, and who else drinks it
Citizens draws surface water from the West Fork of the White River (backed by Morse Reservoir), Fall Creek (backed by Geist and Citizens reservoirs) and Eagle Creek Reservoir, and also uses wells and six groundwater treatment plants.
Citizens Energy Group serves about 880,345 people directly, and 11 other water systems buy water from it, serving about 141,580 more. If you live in one of them, most of what’s on this page describes your water too, though hardness and disinfectant can change if your system blends in its own wells.
The 2025 data table combines Indianapolis with the Morgan County system (IN5255019).
Indianapolis’s water system had no health-based violations in the five years through September 2026, according to EPA’s federal database.
Largest systems that buy from Citizens Energy Group
- Citizens Water of Westfield, LLC61,493
- Brownsburg Water Works31,250
- Citizens Water - Whitestown15,695
- Danville Water Works10,500
- Morgan County Rural Water Company8,800
- Citizens Water - Morgan5,705
- Pittsboro Water Company4,113
- Tri-county Conservancy District3,078
- Town of Lizton Water Utility488
- Carmel Clay Water393
From EPA’s federal drinking water database (SDWIS), 2026Q3: community systems with an active connection buying from IN5249004. Population served.
ZIP codes Citizens Energy Group reports serving (55)
46032 · 46037 · 46038 · 46040 · 46055 · 46062 · 46077 · 46107 · 46112 · 46113 · 46123 · 46140 · 46143 · 46163 · 46183 · 46201 · 46202 · 46203 · 46204 · 46205 · 46206 · 46208 · 46214 · 46216 · 46217 · 46218 · 46219 · 46220 · 46221 · 46222 · 46224 · 46225 · 46226 · 46227 · 46228 · 46229 · 46231 · 46234 · 46235 · 46236 · 46237 · 46239 · 46240 · 46241 · 46249 · 46250 · 46251 · 46254 · 46256 · 46259 · 46260 · 46268 · 46278 · 46282 · 46285
From EPA’s UCMR 5 ZIP file. A ZIP can be served by more than one system; your water bill names yours. Look up any ZIP.
04 · Questions
Indianapolis water questions
Is Indianapolis tap water safe to drink?
The U.S. Environmental Protection Agency (EPA) doesn’t grade a city’s tap water as safe or unsafe; it sets limits and records violations. By that record, Indianapolis’s water system had no health-based violations of federal drinking water rules in the five years through September 2026. EPA’s 2023–24 testing found no PFOA or PFOS (two PFAS “forever chemicals”) samples above its 4 parts per trillion (ppt) limit.
Is Indianapolis tap water hard?
Indianapolis tap water is very hard: about 18.5 grains per gallon (317 milligrams per liter (mg/L)), according to published water quality data from Citizens Energy Group (2025).
Does Indianapolis tap water have PFAS?
The U.S. Environmental Protection Agency’s (EPA’s) national testing (sampled 2023 to 2024) found no PFOA or PFOS (two PFAS “forever chemicals”) at or above 4 parts per trillion (ppt) in any of 26 samples, which puts Indianapolis under EPA’s limit for both.
Does Indianapolis use chlorine or chloramine?
Chloramine. Citizens adds chlorine and a small amount of ammonia, and reports chloramines (measured as total chlorine) in the Indianapolis distribution system at a 2025 average of 2.0 parts per million (ppm).
Has Indianapolis’s water system had violations?
Indianapolis’s water system had no health-based violations in the five years through September 2026, according to the U.S. Environmental Protection Agency’s (EPA’s) federal database.
Nearest cities we cover
Sources
- 01Citizens Energy Group, 2025 water quality data (hardness), read 2026-11-04
- 02Citizens Energy Group (source water)
- 03Citizens Energy Group (disinfectant)
- 04EPA, Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) occurrence data, file posted 2026-10-15
- 05EPA, Safe Drinking Water Information System via ECHO, 2026Q3 file
- 06EPA, PFAS National Primary Drinking Water Regulation, 89 FR 32532
- 07USGS Water Science School, "Hardness of Water"
EPA system ID IN5249004 · Citizens Energy Group