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Stonewall WCID

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
726 people
Connections
243
Water source
Groundwater
Based in
Stonewall, TX
County
Gillespie
Owner
Local government
The ZIP code it serves

78671

The short answer

3 results are above the health goal. The worst: Arsenic, above the health goal. 1 health-based violation since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 1996 to 2025.

Arsenic, uranium, total trihalomethanes (TTHM), nitrate, fluoride, haloacetic acids (HAA5) and chromium (total): Texas’s own results, samples taken from May 19, 2020 to Aug. 13, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal3

Arsenic

Comes from the source

Above the health goal

2.4ppb

Highest yearly average, 2022 to 2025

Averaged by year, the highest was 2.4 ppb, in 2025: below EPA’s legal limit of 10 ppb, but above its health goal of zero. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.0 ppb, in 2019.

What handles it

  • NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
  • NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”

Lead

Comes from pipes, often your own

Above the health goal

1.6ppb

90th percentile, 2023 to 2025

In the latest period, 9 in 10 homes sampled were at or below 1.6 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Uranium

Comes from the source

Above the health goal

2.6ppb

Highest yearly average, 2021

Averaged by year, the highest was 2.6 ppb, in 2021: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.6 ppb, in 2015.

What handles it

Below EPA’s limits4

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

63.7ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 63.7 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 20.9 ppb, in 2019.

What handles it

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

Nitrate

Comes from the source

Below EPA’s limits

4.0ppm

Highest sample; found in 7 of 7

2026, one sample: 4.0 ppm

The highest sample, in 2024, was 4.0 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its one sample was 4.0 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 3.8 ppm, in 2019.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.61ppm

Highest yearly average, 2021 to 2024

Averaged by year, the highest was 0.61 ppm, in 2024, below EPA’s legal limit of 4.0 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.56 ppm, in 2018.

What handles it

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

6.6ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 6.6 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 5.6 ppb, in 2017.

What handles it

No certification claim covers this compound yet.

One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Chromium (total)

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

  • NSF/ANSI 53

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Arsenic, Lead

    Other certifiers’ wording: Arsenic (III) (50 ppb influent level)

  • NSF/ANSI 58

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction, Uranium

    For: Arsenic, Lead, Uranium

    Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. How whole-house systems compare.

Filters with those claims on a certifier’s listing

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Compare five-year costs

The best reverse osmosis systems, ranked

The best water filters for lead, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Lead and Copper Rule RevisionsThe required inventory of lead service lines was not completed or submitted on time.EPA: LSL InventoryOct. 17, 2024—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 2 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Arsenic, uranium, total trihalomethanes (TTHM), nitrate, fluoride, haloacetic acids (HAA5) and chromium (total) results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. Stonewall WCID’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 May 19, 2020 to Aug. 13, 2026.

Testing your own tap

Stonewall WCID’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 Stonewall WCID serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Environmental Monitoring Lab

    Llano, TX · about 33 miles

    Certified for bacteria

    (325) 247-3295

  • Edwards Aquifer Research & Data Center, Texas State University

    San Marcos, TX · about 46 miles

    Certified for bacteria

    (512) 245-2329

  • Alamo Analytical Laboratories, Ltd.

    San Antonio, TX · about 48 miles

    Certified for lead and copper

    (210) 340-8121

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 TX0860104. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Gillespie County

All Texas utilities

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