Skip to content
TapBuff
ZIP

Riverside 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
1,060 people
Connections
520
Water source
Groundwater
Based in
Riverside, IA
County
Washington
Owner
Local government
The ZIP code it serves

52327

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, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, chromium (total) and nitrate: Iowa’s own results, samples taken from April 28, 2020 to July 23, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Arsenic

Comes from the source

Above the health goal

2.5ppb

Highest yearly average, 2024

Averaged by year, the highest was 2.5 ppb, in 2024: 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 2.0 ppb, in 2015.

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 limits3

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

14.8ppb

Highest yearly average, 2020 to 2026

2026, one sample: 7.4 ppb

Averaged by year, the highest was 14.8 ppb, in 2021, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, its one sample was 7.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 10.4 ppb, in 2017.

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

10.8ppb

Highest yearly average, 2020 to 2026

2026, one sample: 9.0 ppb

Averaged by year, the highest was 10.8 ppb, in 2025, below EPA’s legal limit of 60 ppb. In 2026, the latest year on file, its one sample was 9.0 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 5.5 ppb, in 2017.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.4ppm

Highest yearly average, 2024

Averaged by year, the highest was 0.4 ppm, in 2024, 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 0.45 ppm, in 2015.

What handles it

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

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 is 1 monitoring or reporting violation: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, chromium (total) and nitrate results here are Iowa’s own from 2020 on, with EPA’s national file for 2012 to 2019. Riverside 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 April 28, 2020 to July 23, 2026.

Testing your own tap

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

  • State Hygienic Laboratory - Coralville

    Coralville, IA · about 15 miles

    Certified for bacteria, nitrate, organic chemicals, disinfection byproducts, PFAS, radioactivity

    (319) 335-4500

  • Ion Environmental Solutions

    Muscatine, IA · about 27 miles

    Certified for bacteria, nitrate

    (563) 299-2214

  • Linn County Public Health Department

    Cedar Rapids, IA · about 35 miles

    Certified for bacteria, nitrate

    (319) 892-6000

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 IA9260090. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Washington County

All Iowa utilities

What to do next