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City of Cotulla Public Water Supply

What EPA’s and Texas’s records show in this utility’s water: PFAS and lithium; nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves
5,640 people
Connections
1,741
Water source
Groundwater
Based in
Cotulla, TX
County
La Salle
Owner
Local government
The 2 ZIP codes it serves

78001, 78014

The short answer

1 result is above the health goal, and 1 more is above EPA’s health benchmark. The worst: Lithium, above EPA’s health benchmark. 1 health-based violation since 2016.

What handles it

What was found

PFAS and lithium: EPA UCMR 5, samples taken from Feb. 7, 2023 to Oct. 16, 2023.

Arsenic, total trihalomethanes (TTHM), fluoride, haloacetic acids (HAA5), nitrate, chromium (total) and uranium: Texas’s own results, samples taken from Feb. 3, 2020 to Aug. 10, 2026, with EPA’s 2012 to 2019 file for earlier years.

PFAS: None of the six PFAS in EPA’s 2024 drinking water rule was found in this utility’s samples. None of the other 23 PFAS tested for was found either.

EPA’s 2024 PFAS rule, compound by compound

PFASEPA’s limitResult
PFOA4.0 pptNot foundNot found in any of 7 samples, below 4 ppt
PFOS4.0 pptNot foundNot found in any of 7 samples, below 4 ppt
PFHxS10 pptNot foundNot found in any of 7 samples, below 3 ppt
PFNA10 pptNot foundNot found in any of 7 samples, below 4 ppt
HFPO-DA (GenX)10 pptNot foundNot found in any of 7 samples, below 5 ppt
PFBSIndex onlyNot foundNot found in any of 7 samples, below 3 ppt
Hazard IndexPFHxS, PFNA, HFPO-DA and PFBS together1Doesn’t applyDoesn’t apply: no sampling location found two or more of the four
Results from EPA’s UCMR 5 sampling. “Below” is the lab’s reporting level: a result under it reads as not found, which is not the same as zero. The limits are EPA’s 2024 rule, with compliance due from 2029; EPA has since proposed changes to some of them, explained on each compound’s page. PFBS has no limit of its own and counts only toward the Hazard Index, which adds up the four, each against EPA’s health-based level, from each sampling location’s average, as EPA’s UCMR 5 summary does. It counts only where two or more of the four were found, and is above the limit from 1.5.

Above the health goal1

Arsenic

Comes from the source

Above the health goal

0.7ppb

Highest yearly average, 2022 to 2025

2025: not found

Averaged by year, the highest was 0.7 ppb, in 2022: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 2.1 ppb. In 2025, the latest year on file, it wasn’t found in any of its two samples. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.4 ppb, in 2016.

What handles it

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

Above EPA’s health benchmark1

Lithium

Comes from the source

Above EPA’s health benchmark

42.9ppb

Highest sample, Feb. 7, 2023; found in 7 of 7

The highest sample was 42.9 ppb, about 4.3 times EPA’s health reference level of 10 ppb. That is a screening level, not an enforceable limit.

What handles it

No certification claim covers this compound yet.

Below EPA’s limits4

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

16.2ppb

Highest yearly average, 2020 to 2026

2026, one sample: 9.5 ppb

Averaged by year, the highest was 16.2 ppb, in 2021, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, its one sample was 9.5 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 15.2 ppb, in 2017.

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

Below EPA’s limits

0.46ppm

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 0.46 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.47 ppm. In 2026, 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 0.46 ppm, in 2012.

What handles it

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

2.5ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 2.5 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2026, 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 3.5 ppb, in 2012.

What handles it

No certification claim covers this compound yet.

Nitrate

Comes from the source

Below EPA’s limits

0.06ppm

Highest sample; found in 1 of 19

2026: not found

The highest sample, in 2022, was 0.06 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.05 ppm, in 2017.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
Texas utilities above EPA’s PFAS limits
32 compounds tested and not foundIncluding all six PFAS in EPA’s 2024 rule. Below the reporting level in every sample. Not found is not the same as zero.

From routine monitoring

  • Chromium (total)
  • Lead
  • Uranium

PFAS and lithium, from EPA’s UCMR 5 sampling

  • 11Cl-PF3OUdS
  • 4:2 FTS
  • 6:2 FTS
  • 8:2 FTS
  • 9Cl-PF3ONS
  • ADONA
  • HFPO-DA (GenX)
  • NEtFOSAA
  • NFDHA
  • NMeFOSAA
  • PFBA
  • PFBS
  • PFDA
  • PFDoA
  • PFEESA
  • PFHpA
  • PFHpS
  • PFHxA
  • PFHxS
  • PFMBA
  • PFMPA
  • PFNA
  • PFOA
  • PFOS
  • PFPeA
  • PFPeS
  • PFTA
  • PFTrDA
  • PFUnA

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

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

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

  • NSF/ANSI 58

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

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

At the tap, or for the whole house?

These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. 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

Disinfectant

City of Cotulla Public Water Supply reported disinfecting with chlorine, not chloramine, at all 4 of its sampling points, in its 2023 sampling for EPA.

Chlorine leaves water that sits out for a few days, CDC says. A filter certified for it carries a chlorine claim under NSF/ANSI 42; a shower filter, a free chlorine claim under NSF/ANSI 177. This is what the utility reported for that sampling. Its annual water quality report says what it uses now.

Chlorine vs. chloramineShower filters, by what their listings cover

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—Unaddressed
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 27 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Arsenic, total trihalomethanes (TTHM), fluoride, haloacetic acids (HAA5), nitrate, chromium (total) and uranium results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. City of Cotulla Public Water Supply’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 samples are from Feb. 7, 2023 to Oct. 16, 2023; Texas’s results run from Feb. 3, 2020 to Aug. 10, 2026.

Testing your own tap

City of Cotulla Public Water Supply’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 lab Texas certifies closest to the area City of Cotulla Public Water Supply serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • City of Laredo Health Department Lab

    Laredo, TX · about 60 miles

    Certified for bacteria

    (956) 795-4908

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 TX1420001. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in La Salle County

All Texas utilities

What to do next