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Town of Zwolle Water System

What EPA’s and CDC’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
2,520 people
Connections
840
Water source
Groundwater
Based in
Zwolle, LA
County
Sabine Parish
Owner
Local government
The ZIP code it serves

71486

The short answer

1 result is above EPA’s legal limit. The worst: Total trihalomethanes (TTHM), above the legal limit. 24 health-based violations since 2016.

What handles it

What was found

Total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate: Louisiana’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2022, with EPA’s 2012 to 2019 file for earlier years.

Fluoride, arsenic, chromium (total) and uranium: EPA’s compliance monitoring file, samples taken from March 31, 2014 to March 23, 2018. Newer results are in the utility’s annual water quality report.

Above the legal limit1

Total trihalomethanes (TTHM)

Forms or is added in treatment

Above the legal limit

86.5ppb

Highest yearly average, 2020 to 2022

2022 average: 44.6 ppb

Averaged by year, the highest was 86.5 ppb, in 2021, above EPA’s legal limit of 80 ppb. In 2022, the latest year on file, it averaged 44.6 ppb. EPA recorded violations for total trihalomethanes (TTHM) at this utility in 2020, 2021, 2022, 2023 and 2024. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 81 ppb, in 2018, and EPA recorded violations in 2015, 2016, 2017 and 2018.

What handles it

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

Below EPA’s limits2

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

36ppb

Highest yearly average, 2020 to 2022

2022 average: 19.7 ppb

Averaged by year, the highest was 36 ppb, in 2021, below EPA’s legal limit of 60 ppb. In 2022, the latest year on file, it averaged 19.7 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 43.6 ppb, in 2018.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

1.9ppm

Highest yearly average, 2014 to 2018

2018 average: 1.6 ppm

Averaged by year, the highest was 1.9 ppm, in 2015, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 4.1 ppm. In 2018, the latest year on file, its two samples averaged 1.6 ppm. EPA recorded no violation for fluoride at this utility from 2012 to 2019.

What handles it

5 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Chromium (total)
  • Lead
  • 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

    Claim: Trihalomethanes (TTHM) Reduction

    For: Total trihalomethanes (TTHM)

    Other certifiers’ wording: VOC Reduction

  • NSF/ANSI 58

    Claim: Trihalomethanes (TTHM) Reduction

    For: Total trihalomethanes (TTHM)

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

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2024 to Dec. 31, 20240.086 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2024 to Sept. 30, 20240.088 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2024 to June 30, 20240.1 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2024 to March 31, 20240.1 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2023 to Dec. 31, 20230.084 MG/LResolved
Revised Total Coliform RuleColiform results required a check of the system, and the check or its fixes were not done on time.EPA: Treatment Technique, Level 1 Assessment (RTCR)April 15, 2022—Resolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2022 to June 30, 20220.083 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2022 to March 31, 20220.09 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2021 to Dec. 31, 20210.11 MG/LResolved
Groundwater RuleA significant problem found in a state inspection was not fixed on time.EPA: Failure To Address DeficiencyJuly 2, 2021—Resolved
Groundwater RuleA significant problem found in a state inspection was not fixed on time.EPA: Failure To Address DeficiencyJuly 2, 2021—Resolved
Groundwater RuleA significant problem found in a state inspection was not fixed on time.EPA: Failure To Address DeficiencyJuly 2, 2021—Resolved
Groundwater RuleA significant problem found in a state inspection was not fixed on time.EPA: Failure To Address DeficiencyJuly 2, 2021—Resolved
Groundwater RuleA significant problem found in a state inspection was not fixed on time.EPA: Failure To Address DeficiencyJuly 2, 2021—Resolved
Groundwater RuleA significant problem found in a state inspection was not fixed on time.EPA: Failure To Address DeficiencyJuly 2, 2021—Resolved
Groundwater RuleA significant problem found in a state inspection was not fixed on time.EPA: Failure To Address DeficiencyJuly 2, 2021—Resolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2021 to Sept. 30, 20210.11 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2021 to June 30, 20210.087 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2021 to March 31, 20210.083 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2020 to June 30, 20200.088 MG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2018 to Sept. 30, 201890 UG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2018 to March 31, 201889 UG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2017 to June 30, 2017101 UG/LResolved
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2016 to March 31, 201683 UG/LResolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 8 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 Louisiana’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride, arsenic, chromium (total) and uranium come from EPA’s file alone, which ends in 2019. Town of Zwolle Water System’s own annual report, which it must send you every year, has newer results for those and 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; CDC’s yearly averages for Louisiana cover 2020 to 2022; EPA’s compliance samples are from March 31, 2014 to March 23, 2018.

Testing your own tap

Town of Zwolle Water System’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 Louisiana certifies.

The 3 labs Louisiana certifies closest to the area Town of Zwolle Water System serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • JRTC & Fort Johnson Environmental Laboratory

    Fort Polk, LA · about 48 miles

    Certified for bacteria

    (337) 531-9128

  • LDH Shreveport Regional Laboratory

    Shreveport, LA · about 58 miles

    Certified for bacteria

    (318) 676-7809

  • LDH Rapides Regional Laboratory

    Alexandria, LA · about 68 miles

    Certified for bacteria

    (318) 487-5282

All 48 certified labs for Louisiana

Sources

PWSID LA1085032. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Sabine Parish

All Louisiana utilities

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