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Gilbert Water Supply

What EPA’s and Iowa’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
1,211 people
Connections
512
Water source
Groundwater
Based in
Gilbert, IA
County
Story
Owner
Local government
The ZIP code it serves

50105

The short answer

2 results are above the limit’s level with no violation recorded, and 1 more is above the health goal. The worst: Haloacetic acids (HAA5), above the limit’s level, no violation. No health-based violations on file since 2016.

What handles it

What was found

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 1.7 ppm, for the period ending Dec. 31, 2009. None since is on file, so it is not counted as a current finding.

Haloacetic acids (HAA5), total trihalomethanes (TTHM), arsenic, nitrate, fluoride and chromium (total): Iowa’s own results, samples taken from Jan. 6, 2020 to Aug. 21, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the limit’s level, no violation recorded2

Haloacetic acids (HAA5)

Forms or is added in treatment

Above the limit’s level, no violation

66ppb

Highest yearly average, 2020 to 2026

2026 average: 38.3 ppb

Averaged by year, the highest was 66 ppb, in 2021, above EPA’s legal limit of 60 ppb. Its highest single sample was 70 ppb. In 2026, the latest year on file, its six samples averaged 38.3 ppb. EPA judges this limit on running averages at each sampling point, and recorded no violation for haloacetic acids (HAA5) at this utility since 2020. Results like these with no violation often include water sampled before treatment or blending; the utility’s annual report says what reaches the tap. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 8.0 ppb, in 2018.

What handles it

No certification claim covers this compound yet.

Total trihalomethanes (TTHM)

Forms or is added in treatment

Above the limit’s level, no violation

87ppb

Highest yearly average, 2020 to 2026

2026 average: 51.3 ppb

Averaged by year, the highest was 87 ppb, in 2021, above EPA’s legal limit of 80 ppb. Its highest single sample was 120 ppb. In 2026, the latest year on file, its six samples averaged 51.3 ppb. EPA judges this limit on running averages at each sampling point, and recorded no violation for total trihalomethanes (TTHM) at this utility since 2020. Results like these with no violation often include water sampled before treatment or blending; the utility’s annual report says what reaches the tap. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 7.6 ppb, in 2018.

What handles it

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

Above the health goal1

Arsenic

Comes from the source

Above the health goal

5.0ppb

Highest yearly average, 2020 to 2025

2025, one sample: 4.0 ppb

Averaged by year, the highest was 5.0 ppb, in 2021: below EPA’s legal limit of 10 ppb, but above its health goal of zero. In 2025, the latest year on file, its one sample was 4.0 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 6.5 ppb, in 2013.

What handles it

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

Below EPA’s limits2

Nitrate

Comes from the source

Below EPA’s limits

2.8ppm

Highest sample; found in 20 of 22

2026 average: 1.4 ppm

The highest sample, in 2022, was 2.8 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its two samples averaged 1.4 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 2.2 ppm, in 2019.

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

0.6ppm

Highest yearly average, 2022

Averaged by year, the highest was 0.6 ppm, in 2022, below EPA’s legal limit of 4.0 ppm. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.53 ppm, in 2013.

What handles it

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

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, Arsenic (Pentavalent)<=50 ppb Reduction

    For: Total trihalomethanes (TTHM), Arsenic

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

  • NSF/ANSI 58

    Claims: Trihalomethanes (TTHM) Reduction, Arsenic (Pentavalent)<=50 ppb Reduction

    For: Total trihalomethanes (TTHM), 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

Violations since 2016

No health-based violations on file with EPA since 2016. There are 33 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Haloacetic acids (HAA5), total trihalomethanes (TTHM), arsenic, nitrate, fluoride and chromium (total) results here are Iowa’s own from 2020 on, with EPA’s national file for 2012 to 2019. Gilbert 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 didn’t sample this utility; Iowa’s results run from Jan. 6, 2020 to Aug. 21, 2026.

Testing your own tap

Gilbert 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 Iowa certifies.

The 3 labs Iowa certifies closest to the area Gilbert Water Supply serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • AgSource

    Ellsworth, IA · about 16 miles

    Certified for bacteria, nitrate, metals, minerals and other inorganics

    (515) 297-8103

  • State Hygienic Laboratory - Ankeny

    Ankeny, IA · about 26 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics

    (515) 725-1600

  • Microbac Laboratories - Newton

    Newton, IA · about 41 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts

    (641) 792-8451

State Hygienic Laboratory at the University of Iowa: Through the Grants-to-Counties program, private well owners in participating counties can have their water tested for total coliform bacteria and nitrate. Start with the county sanitarian at your county health department. No cost in a participating county. The Grants-to-Counties Program, State Hygienic Lab at the University of Iowa.

All 36 certified labs for Iowa

Sources

PWSID IA8531083. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Story County

All Iowa utilities

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