Tap water report · updated November 2026
Austin tap water: moderately hard water, PFOS samples up to 4.8 ppt (EPA limit 4)
What’s in the water Austin Water delivers to 1.1 million people, from national testing by the U.S. Environmental Protection Agency (EPA) and the utility’s own report.
Short answer
Austin tap water is moderately hard: about 5.4 grains per gallon (93 milligrams per liter (mg/L)), according to published water quality data from Austin Water (2025). The U.S. Environmental Protection Agency’s (EPA’s) 2023–24 testing found PFOS (a PFAS “forever chemical”) at 4.8 parts per trillion (ppt) in its highest samples, above the 4 ppt limit utilities must meet by 2029. The system had 1 health-based violation in the five years through September 2026, since resolved.
Sources: Austin Water 2025 data, EPA UCMR 5, EPA SDWIS 2026Q3 · Sources and method
How Austin compares with the 40 systems we track
Hardness
8th softest
of 34 systems
PFOA / PFOS
11th highest
of 11 that detected any
Size
18th 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 Austin 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 knowingHardness 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 5.4 gpg, Austin water is in the middle of the scale, the 8th-softest of the 34 systems we track. Some homes notice spots; many don’t.
What to do: A softener is optional. If spots bother you, a small one does the job.
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)
Worth acting onPFAS 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: Austin’s highest PFOS sample was 4.8 ppt, about 1.2 times EPA’s 4 ppt limit, the 11th-highest of the 40 we track. 11 of the 40 had a sample over the limit; 29 had none detected at all. These are samples from EPA’s 2023–24 testing, not a violation: utilities have until 2029 to get under the limit on a yearly average.
What to do: A filter on the tap you drink and cook from handles it. Look for reverse osmosis certified to NSF/ANSI 58, or carbon certified to NSF/ANSI 53, for PFOA and PFOS by name.
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: Austin 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
Worth knowingA 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: Austin’s system had 1 in the five years through September 2026, all since resolved. 36 of the 40 systems we track had none.
What to do: Utilities must notify customers when a violation happens. The utility’s annual water quality report explains what happened and what was fixed.
Learn more →How Austin 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.
- 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 Austin
02 · The full results
Every PFAS result EPA recorded
In EPA’s national testing (sampled 2023 to 2024), Austin’s highest samples reached PFOS at 4.8 ppt, above EPA’s 4 ppt limit. These are individual samples, not a compliance finding: water systems have until 2029 to meet the limit, judged on a yearly average.
Results from EPA’s national testing program (UCMR 5) for Austin Water, 3 sampling points, October 2023 to July 2024. Concentrations in parts per trillion (ppt).
| Chemical | Samples | Detected | Highest | EPA limit |
|---|---|---|---|---|
| PFOA (perfluorooctanoic acid) | 12 | 0 | none | 4 |
| PFOS (perfluorooctane sulfonic acid) | 12 | 2 | 4.8 | 4 |
| PFHxS | 12 | 6 | 6.2 | 10 |
| PFNA | 12 | 0 | none | 10 |
| HFPO-DA (GenX) | 12 | 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
Austin Water draws surface water from the Lower Colorado River as it flows through Lake Travis and Lake Austin and treats it at three plants.
Austin Water serves about 1.1 million people directly, and 18 other water systems buy water from it, serving about 287,496 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.
Austin Water tests distribution system sites more than 300 times a month for E. coli, and no sample was positive in 2025.
EPA’s federal database shows 1 health-based violation in the five years through September 2026. The system missed a required treatment step under EPA’s rules for treating river and lake water in February 2022, since resolved.
Largest systems that buy from Austin Water
- City of Round Rock130,662
- Travis County WCID 1745,165
- Windermere Community21,231
- City of Manor19,620
- Wells Branch MUD 118,015
- Northtown MUD11,520
- North Austin MUD 111,133
- Travis County WCID 109,204
- Creedmoor Maha WSC8,907
- Shady Hollow MUD4,269
From EPA’s federal drinking water database (SDWIS), 2026Q3: community systems with an active connection buying from TX2270001. Population served.
ZIP codes Austin Water reports serving (48)
78610 · 78613 · 78617 · 78652 · 78653 · 78660 · 78681 · 78701 · 78702 · 78703 · 78704 · 78705 · 78712 · 78717 · 78719 · 78721 · 78722 · 78723 · 78724 · 78725 · 78726 · 78727 · 78728 · 78729 · 78730 · 78731 · 78732 · 78735 · 78736 · 78737 · 78739 · 78741 · 78742 · 78744 · 78745 · 78746 · 78747 · 78748 · 78749 · 78750 · 78751 · 78752 · 78753 · 78754 · 78756 · 78757 · 78758 · 78759
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
Austin water questions
Is Austin 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, Austin’s water system had 1 health-based violation in the five years through September 2026, all since resolved. Separately, EPA’s 2023–24 testing found PFOA or PFOS (two PFAS “forever chemicals”) samples above the 4 parts per trillion (ppt) limit that utilities must meet, on a yearly average, by 2029. A filter certified to NSF/ANSI 53 or 58 for PFOA and PFOS addresses it at the tap.
Is Austin tap water hard?
Austin tap water is moderately hard: about 5.4 grains per gallon (93 milligrams per liter (mg/L)), according to published water quality data from Austin Water (2025).
Does Austin tap water have PFAS?
In the U.S. Environmental Protection Agency’s (EPA’s) national testing (sampled 2023 to 2024), Austin’s highest samples reached PFOS (a PFAS “forever chemical”) at 4.8 parts per trillion (ppt), above EPA’s 4 ppt limit. These are individual samples, not a compliance finding: water systems have until 2029 to meet the limit, judged on a yearly average.
Does Austin use chlorine or chloramine?
Chloramine. Austin Water states that it uses chloramine to disinfect drinking water, and its 2025 distribution system chloramine average was 2.3 parts per million (ppm).
Has Austin’s water system had violations?
The U.S. Environmental Protection Agency’s (EPA’s) federal database shows 1 health-based violation in the five years through September 2026. The system missed a required treatment step under EPA’s rules for treating river and lake water in February 2022, since resolved.
Nearest cities we cover
Sources
- 01Austin Water, 2025 water quality data (hardness), read 2026-11-04
- 02Austin Water (source water)
- 03Austin Water (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 TX2270001 · Austin Water