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High Prairie Water Supply Corp

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
1,476 people
Connections
492
Water source
Groundwater
Based in
Madisonville, TX
County
Madison
Owner
Local government
The 3 ZIP codes it serves

77864, 77871, 77872

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), haloacetic acids (HAA5), chromium (total), fluoride, nitrate, arsenic and uranium: Texas’s own results, samples taken from June 23, 2020 to May 14, 2026, with EPA’s 2012 to 2019 file for earlier years.

Below EPA’s limits5

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

13.3ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 13.3 ppb, in 2026, 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 6.7 ppb, in 2018.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

3.4ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 3.4 ppb, in 2026, below EPA’s legal limit of 60 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.4 ppb, in 2015.

What handles it

No certification claim covers this compound yet.

Chromium (total)

Comes from the source

Below EPA’s limits

2.1ppb

Highest yearly average, 2021 to 2024

2024: not found

Averaged by year, the highest was 2.1 ppb, in 2021, below EPA’s legal limit of 100 ppb. In 2024, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.3 ppb, in 2015.

What handles it

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.084ppm

Highest yearly average, 2021 to 2024

2024, one sample: 0.067 ppm

Averaged by year, the highest was 0.084 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. In 2024, the latest year on file, its one sample was 0.067 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.11 ppm, in 2012.

What handles it

Nitrate

Comes from the source

Below EPA’s limits

0.046ppm

Highest sample; found in 7 of 7

2026, one sample: 0.029 ppm

The highest sample, in 2023, was 0.046 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its one sample was 0.029 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.17 ppm, in 2014.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Lead
  • Uranium

Violations since 2016

No health-based violations on file with EPA since 2016. There are 2 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM), haloacetic acids (HAA5), chromium (total), fluoride, nitrate, arsenic and uranium results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. High Prairie Water Supply Corp’s own annual report, which it must send you every year, has 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 June 23, 2020 to May 14, 2026.

Testing your own tap

High Prairie Water Supply Corp’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Texas certifies.

The 3 labs Texas certifies closest to the area High Prairie Water Supply Corp serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Chaparral Laboratories, Inc.

    Huntsville, TX · about 32 miles

    Certified for bacteria, lead and copper

    (936) 291-1881

  • Aqua-Tech Laboratories, Inc.

    Bryan, TX · about 32 miles

    Certified for bacteria, lead and copper

    (979) 778-3707

  • Eastex Environmental Lab, Inc. -Coldspring

    Coldspring, TX · about 58 miles

    Certified for bacteria, lead and copper

    (936) 653-3249

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 Texas

Sources

PWSID TX1570018. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Madison County

All Texas utilities

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