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Capstone Subdivision

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
81 people
Connections
27
Water source
Groundwater
Based in
Marble Falls, TX
County
Burnet
Owner
Private
The ZIP code it serves

78654

The short answer

1 result is above EPA’s legal limit, and 2 more are above the health goal. The worst: Total trihalomethanes (TTHM), above the legal limit. 9 health-based violations since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2017 to 2025.

Total trihalomethanes (TTHM), uranium, haloacetic acids (HAA5), nitrate, fluoride, arsenic and chromium (total): Texas’s own results, samples taken from March 13, 2020 to July 23, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the legal limit1

Total trihalomethanes (TTHM)

Forms or is added in treatment

Above the legal limit

109ppb

Highest yearly average, 2020 to 2026

2026 average: 43.6 ppb

Averaged by year, the highest was 109 ppb, in 2024, above EPA’s legal limit of 80 ppb. Its highest single sample was 150 ppb. In 2026, the latest year on file, its three samples averaged 43.6 ppb. EPA recorded violations for total trihalomethanes (TTHM) at this utility in 2024 and 2025. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 99 ppb, in 2015, and EPA recorded a violation in 2016.

What handles it

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

Above the health goal2

Lead

Comes from pipes, often your own

Above the health goal

7.9ppb

90th percentile, 2023 to 2025

In the latest period, 9 in 10 homes sampled were at or below 7.9 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

1.2ppb

Highest yearly average, 2021 to 2024

2024, one sample: 1.1 ppb

Averaged by year, the highest was 1.2 ppb, in 2021: below EPA’s legal limit of 30 ppb, but above its health goal of zero. In 2024, the latest year on file, its one sample was 1.1 ppb.

What handles it

Below EPA’s limits3

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

31.2ppb

Highest yearly average, 2020 to 2026

2026 average: 14.2 ppb

Averaged by year, the highest was 31.2 ppb, in 2024, below EPA’s legal limit of 60 ppb. Its highest single sample was 52.6 ppb. In 2026, the latest year on file, its three samples averaged 14.2 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 44.6 ppb, in 2015.

What handles it

No certification claim covers this compound yet.

Nitrate

Comes from the source

Below EPA’s limits

1.4ppm

Highest sample; found in 8 of 8

2026, one sample: 0.51 ppm

The highest sample, in 2021, was 1.4 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its one sample was 0.51 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.51 ppm, in 2016.

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

0.16ppm

Highest yearly average, 2021 to 2024

2024, one sample: 0.12 ppm

Averaged by year, the highest was 0.16 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. In 2024, the latest year on file, its one sample was 0.12 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.21 ppm, in 2012.

What handles it

2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • 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: Trihalomethanes (TTHM) Reduction, Lead Reduction

    For: Total trihalomethanes (TTHM), Lead

    Other certifiers’ wording: VOC Reduction

  • NSF/ANSI 58

    Claims: Trihalomethanes (TTHM) Reduction, Lead Reduction, Uranium

    For: Total trihalomethanes (TTHM), Lead, Uranium

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 water filters for lead, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2025 to Dec. 31, 20250.086 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2025 to Sept. 30, 20250.09 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2025 to June 30, 20250.1 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2025 to March 31, 20250.11 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2024 to Dec. 31, 20240.11 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2024 to Sept. 30, 20240.095 MG/LResolved
Lead and Copper RuleA required study or plan for corrosion control was not done on time.EPA: OCCT/SOWT Study/RecommendationOct. 1, 2020—Unaddressed
Lead and Copper RuleRequired information about lead was not given to customers.EPA: Public EducationDec. 1, 2019—Resolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2016 to June 30, 20160.085 MG/LResolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 11 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM), uranium, haloacetic acids (HAA5), nitrate, fluoride, arsenic and chromium (total) results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. Capstone Subdivision’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 March 13, 2020 to July 23, 2026.

Testing your own tap

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

  • Integrity Testing, Inc.

    Austin, TX · about 29 miles

    Certified for lead and copper

    (512) 891-7777

  • Environmental Monitoring Lab

    Llano, TX · about 30 miles

    Certified for bacteria

    (325) 247-3295

  • Texas Department of State Health Services Laboratory Services Section

    Austin, TX · about 33 miles

    Certified for bacteria, lead and copper

    (512) 458-7318

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 TX0270131. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Burnet County

All Texas utilities

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