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Zapata County WCID Hwy 16 East

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
243 people
Connections
81
Water source
Surface water bought from another system
Based in
Zapata, TX
County
Zapata
Owner
Local government
The ZIP code it serves

78076

The short answer

1 result is above the health goal. The worst: Lead, above the health goal. 1 health-based violation since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 1995 to 2023.

Total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate: Texas’s own results, samples taken from Feb. 5, 2020 to Sept. 2, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Lead

Comes from pipes, often your own

Above the health goal

1.1ppb

90th percentile, 2021 to 2023

In the latest period, 9 in 10 homes sampled were at or below 1.1 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

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

42.1ppb

Highest yearly average, 2020 to 2026

2026 average: 28.4 ppb

Averaged by year, the highest was 42.1 ppb, in 2022, below EPA’s legal limit of 80 ppb. Its highest single sample was 51.1 ppb. In 2026, the latest year on file, its three samples averaged 28.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 60.1 ppb, in 2015.

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

25.1ppb

Highest yearly average, 2020 to 2026

2026 average: 7.3 ppb

Averaged by year, the highest was 25.1 ppb, in 2022, below EPA’s legal limit of 60 ppb. Its highest single sample was 46.6 ppb. In 2026, the latest year on file, its three samples averaged 7.3 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 33.9 ppb, in 2013.

What handles it

No certification claim covers this compound yet.

Nitrate

Comes from the source

Below EPA’s limits

1.9ppm

Highest sample; found in 6 of 6

2025, one sample: 1.0 ppm

The highest sample, in 2022, was 1.9 ppm, below EPA’s legal limit of 10 ppm. In 2025, the latest year on file, its one sample was 1.0 ppm.

What handles it

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

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.”

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
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. 5 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate results here are Texas’s own from 2020 on, with EPA’s national file for 2012 to 2019. Zapata County WCID Hwy 16 East’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. 5, 2020 to Sept. 2, 2026.

Testing your own tap

Zapata County WCID Hwy 16 East’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 Zapata County WCID Hwy 16 East 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 45 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 TX2530023. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Zapata County

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