Dal High Water System
What EPA’s and Texas’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.
- Serves
- 138 people
- Connections
- 46
- Water source
- Groundwater
- Based in
- Austin, TX
- County
- Henderson
- Owner
- Private
The ZIP code it serves
The short answer
Nothing in EPA’s and Texas’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.
What was found
Total trihalomethanes (TTHM), fluoride, nitrate, arsenic, chromium (total) and haloacetic acids (HAA5): Texas’s own results, samples taken from Aug. 13, 2020 to May 15, 2025, with EPA’s 2012 to 2019 file for earlier years.
Uranium: EPA’s compliance monitoring file, samples taken from May 8, 2017 to May 8, 2017. Newer results are in the utility’s annual water quality report.
Below EPA’s limits3
Total trihalomethanes (TTHM)
Forms or is added in treatment
4.7ppb
Highest yearly average, 2022 to 2025
Averaged by year, the highest was 4.7 ppb, in 2025, below EPA’s legal limit of 80 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 5.0 ppb, in 2019.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Fluoride
Forms or is added in treatment
0.14ppm
Highest yearly average, 2022 to 2025
2025, one sample: 0.11 ppm
Averaged by year, the highest was 0.14 ppm, in 2022, below EPA’s legal limit of 4.0 ppm. In 2025, the latest year on file, its one sample was 0.11 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.15 ppm, in 2013.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Nitrate
Comes from the source
0.037ppm
Highest sample; found in 6 of 6
2025, one sample: 0.035 ppm
The highest sample, in 2020, was 0.037 ppm, below EPA’s legal limit of 10 ppm. In 2025, the latest year on file, its one sample was 0.035 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.037 ppm, in 2019.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
5 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Haloacetic acids (HAA5)
- Lead
- Uranium
Violations since 2016
No health-based violations on file with EPA since 2016. There are 5 monitoring or reporting violations: a sample missed, late or not reported.
What this report can’t tell you
Everything else. Total trihalomethanes (TTHM), fluoride, nitrate, arsenic, chromium (total) and haloacetic acids (HAA5) results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. Uranium comes from EPA’s file alone, which ends in 2019. Dal High Water System’s own annual report, which it must send you every year, has newer results for those and the contaminants this page does not show.
Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.
What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.
Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; Texas’s results run from Aug. 13, 2020 to May 15, 2025; EPA’s compliance samples are from May 8, 2017 to May 8, 2017.
Testing your own tap
The 3 labs Texas certifies closest to the area Dal High Water System serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Analytical Environmental Labs
Tyler, TX · about 28 miles
Certified for bacteria
Northeast Texas Public Health District Laboratory
Tyler, TX · about 29 miles
Certified for bacteria
Environmental Monitoring Lab
Winona, TX · about 44 miles
Certified for bacteria
Texas Well Owner Network, Texas A&M AgriLife Extension: Well Informed screening events, where well owners bring in water samples to be screened for common contaminants, followed by an hour-long session explaining the results. Upcoming events are on the network's calendar. Trainings, Texas Well Owner Network.
All 80 certified labs for TexasSources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- Texas Commission on Environmental Quality, Texas Drinking Water Viewer, results from Jan. 7, 2020 to Oct. 6, 2026, read Oct. 16, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: TCEQ, drinking water laboratories approved for public water system samples, read Oct. 10, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID TX1070159. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and Texas’s records for this utility. They don’t cover everything, which is why the next step matters.Every contaminant TapBuff tracks
- Get the utility’s own reportDal High Water System must send you a water quality report every year. It covers contaminants this page does not show, and has newer results than EPA’s national file for the ones here that come from it.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Decide if you want a filter at allA filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.NSF/ANSI standards, decoded