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Hawarden 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
2,700 people
Connections
1,058
Water source
Groundwater
Based in
Hawarden, IA
County
Sioux
Owner
Local government
The ZIP code it serves

51023

The short answer

1 result is 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

Arsenic, nitrate, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride and chromium (total): Iowa’s own results, samples taken from Jan. 14, 2020 to Sept. 1, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Arsenic

Comes from the source

Above the health goal

1.0ppb

Highest yearly average, 2023

Averaged by year, the highest was 1.0 ppb, in 2023: below EPA’s legal limit of 10 ppb, but above its health goal of zero. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.0 ppb, in 2014.

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 limits4

Nitrate

Comes from the source

Below EPA’s limits

9.0ppm

Highest sample; found in 26 of 27

2026 average: 2.7 ppm

The highest sample, in 2022, was 9.0 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its three samples averaged 2.7 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 8.3 ppm, in 2012.

What handles it

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

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

46.6ppb

Highest yearly average, 2020 to 2026

2026, one sample: 36 ppb

Averaged by year, the highest was 46.6 ppb, in 2023, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, its one sample was 36 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 57 ppb, in 2019.

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

33ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 33 ppb, in 2026, below EPA’s legal limit of 60 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 27 ppb, in 2019.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.8ppm

Highest yearly average, 2020 to 2026

2026 average: 0.57 ppm

Averaged by year, the highest was 0.8 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 1.4 ppm. In 2026, the latest year on file, its nine samples averaged 0.57 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.1 ppm, in 2012.

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

    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

Violations since 2016

No health-based violations on file with EPA since 2016. There are 2 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Arsenic, nitrate, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride and chromium (total) results here are Iowa’s own from 2020 on, with EPA’s national file for 2012 to 2019. Hawarden 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. 14, 2020 to Sept. 1, 2026.

Testing your own tap

Hawarden 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 Hawarden Water Supply serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Siouxland District Health Department

    Sioux City, IA · about 35 miles

    Certified for bacteria, nitrate, minerals and other inorganics

    (712) 234-3908

  • Analytical & Consulting Services

    Sergeant Bluff, IA · about 45 miles

    Certified for bacteria, nitrate

    (712) 943-4888

  • Foundation Analytical Laboratory

    Cherokee, IA · about 49 miles

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

    (712) 225-6989

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 IA8434040. Rebuilt from EPA data on Oct. 18, 2026.

Also in Sioux County

All Iowa utilities

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