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Wilmot Water Users Group

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
30 people
Connections
10
Water source
Groundwater
Based in
Tucson, AZ
County
Pima
Owner
Local government
The ZIP code it serves

85756

The short answer

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

What handles it

What was found

Arsenic and nitrate: Arizona’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2023, with EPA’s 2012 to 2019 file for earlier years.

Fluoride and chromium (total): EPA’s compliance monitoring file, samples taken from Dec. 15, 2014 to Nov. 15, 2017. Newer results are in the utility’s annual water quality report.

Above the health goal1

Arsenic

Comes from the source

Above the health goal

2.9ppb

Highest yearly average, 2020 to 2023

Averaged by year, the highest was 2.9 ppb, in 2023: below EPA’s legal limit of 10 ppb, but above its health goal of zero. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.1 ppb, in 2017.

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

Nitrate

Comes from the source

Below EPA’s limits

1.0ppm

Highest yearly average, 2020 to 2023

Averaged by year, the highest was 1.0 ppm, in 2023, below EPA’s legal limit of 10 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.98 ppm, in 2012.

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

0.24ppm

Highest yearly average, 2014 to 2017

Averaged by year, the highest was 0.24 ppm, in 2017, below EPA’s legal limit of 4.0 ppm. That was also the latest year on file.

What handles it

Chromium (total)

Comes from the source

Below EPA’s limits

1.2ppb

Highest yearly average, 2014 to 2017

Averaged by year, the highest was 1.2 ppb, in 2017, below EPA’s legal limit of 100 ppb. That was also the latest year on file.

What handles it

One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • 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

Contaminant or ruleTypePeriodMeasuredStatus
Revised Total Coliform RuleE. coli was confirmed in the water system.EPA: Maximum Contaminant Level Violation, E. coli (RTCR)Sept. 1, 2018 to Sept. 30, 2018—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 4 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Arsenic and nitrate results here are Arizona’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride and chromium (total) come from EPA’s file alone, which ends in 2019. Wilmot Water Users Group’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 Arizona cover 2020 to 2023; EPA’s compliance samples are from Dec. 15, 2014 to Nov. 15, 2017.

Testing your own tap

Wilmot Water Users Group’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 Arizona certifies.

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

  • Turner Laboratories, Inc.

    Tucson, AZ · about 8 miles

    (520) 882-5880

  • Complete Analytical Services, LLC

    Tucson, AZ · about 8 miles

    (520) 884-5811

  • Legend Technical Services of Arizona, Inc. DBA Legend Analytical

    Tucson, AZ · about 8 miles

    (520) 327-1234

All 49 certified labs for Arizona

Sources

PWSID AZ0410402. Rebuilt from EPA data on Oct. 18, 2026.

Also in Pima County

All Arizona utilities

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