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Fort Bend County MUD 131

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
3,114 people
Connections
1,038
Water source
Groundwater
Based in
Houston, TX
County
Fort Bend
Owner
Local government
The ZIP code it serves

77583

The short answer

2 results are above the health goal. The worst: Arsenic, above the health goal. No health-based violations on file since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2009 to 2026.

Arsenic, fluoride, haloacetic acids (HAA5), total trihalomethanes (TTHM), chromium (total), nitrate and uranium: Texas’s own results, samples taken from Feb. 13, 2020 to July 29, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal2

Arsenic

Comes from the source

Above the health goal

3.7ppb

Highest yearly average, 2020 to 2026

2026, one sample: 2.5 ppb

Averaged by year, the highest was 3.7 ppb, in 2023: below EPA’s legal limit of 10 ppb, but above its health goal of zero. In 2026, the latest year on file, its one sample was 2.5 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 5.1 ppb, in 2017.

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

0.6ppb

90th percentile, 2024 to 2026

In the latest period, 9 in 10 homes sampled were at or below 0.6 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

Below EPA’s limits3

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.8ppm

Highest yearly average, 2020 to 2026

2026, one sample: 0.74 ppm

Averaged by year, the highest was 0.8 ppm, in 2023, below EPA’s legal limit of 4.0 ppm. In 2026, the latest year on file, its one sample was 0.74 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.2 ppm, in 2014.

What handles it

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

9.6ppb

Highest yearly average, 2020 to 2026

2026 average: 2.6 ppb

Averaged by year, the highest was 9.6 ppb, in 2023, below EPA’s legal limit of 60 ppb. Its highest single sample was 9.8 ppb. In 2026, the latest year on file, its two samples averaged 2.6 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.5 ppb, in 2012.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

12.4ppb

Highest yearly average, 2020 to 2026

2026 average: 10.8 ppb

Averaged by year, the highest was 12.4 ppb, in 2021, below EPA’s legal limit of 80 ppb. Its highest single sample was 13.7 ppb. In 2026, the latest year on file, its two samples averaged 10.8 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 14 ppb, in 2015.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Chromium (total)
  • Nitrate
  • Uranium

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

    For: Arsenic, Lead

    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

No health-based violations on file with EPA since 2016.

What this report can’t tell you

  • Everything else. Arsenic, fluoride, haloacetic acids (HAA5), total trihalomethanes (TTHM), chromium (total), nitrate and uranium results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. Fort Bend County MUD 131’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 Feb. 13, 2020 to July 29, 2026.

Testing your own tap

Fort Bend County MUD 131’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 Fort Bend County MUD 131 serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Brazoria County Health Department Water Laboratory

    Angleton, TX · about 14 miles

    Certified for bacteria

    (979) 864-1628

  • Eurofins Xenco, LLC -Houston

    Stafford, TX · about 18 miles

    Certified for lead and copper

    (281) 240-4200

  • ALS Laboratory Group, Environmental Services Division – Houston, Texas

    Houston, TX · about 21 miles

    Certified for lead and copper

    (281) 530-5656

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 TX0790450. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Fort Bend County

All Texas utilities

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