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Cs Antelope Water Company

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
163 people
Connections
65
Water source
Surface water
Based in
Mohawk, AZ
County
Yuma
Owner
Private
The ZIP code it serves

85356

The short answer

1 result is above the limit’s level with no violation recorded, and 2 more are above the health goal. The worst: Total trihalomethanes (TTHM), above the limit’s level, no violation. 5 health-based violations since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2008 to 2024.

Total trihalomethanes (TTHM), haloacetic acids (HAA5) 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.

Arsenic, fluoride and chromium (total): EPA’s compliance monitoring file, samples taken from April 10, 2019 to April 10, 2019. Newer results are in the utility’s annual water quality report.

Above the limit’s level, no violation recorded1

Total trihalomethanes (TTHM)

Forms or is added in treatment

Above the limit’s level, no violation

85ppb

Highest yearly average, 2020 to 2023

2023 average: 45 ppb

Averaged by year, the highest was 85 ppb, in 2020, above EPA’s legal limit of 80 ppb. In 2023, the latest year on file, it averaged 45 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 77 ppb, in 2012.

What handles it

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

Above the health goal2

Lead

Comes from pipes, often your own

Above the health goal

5.0ppb

90th percentile, 2022 to 2024

In the latest period, 9 in 10 homes sampled were at or below 5.0 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Arsenic

Comes from the source

Above the health goal

2.1ppb

Highest yearly average, 2019

Averaged by year, the highest was 2.1 ppb, in 2019: below EPA’s legal limit of 10 ppb, but above its health goal of zero. That is the only year on file.

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

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

21ppb

Highest yearly average, 2020 to 2023

2023 average: 14 ppb

Averaged by year, the highest was 21 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2023, the latest year on file, it averaged 14 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 35 ppb, in 2012.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.35ppm

Highest yearly average, 2019

Averaged by year, the highest was 0.35 ppm, in 2019, below EPA’s legal limit of 4.0 ppm. That is the only year on file.

What handles it

Nitrate

Comes from the source

Below EPA’s limits

0.3ppm

Highest yearly average, 2020 to 2023

2023 average: 0.2 ppm

Averaged by year, the highest was 0.3 ppm, in 2021, below EPA’s legal limit of 10 ppm. In 2023, the latest year on file, it averaged 0.2 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.54 ppm, in 2018.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Chromium (total)

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, Lead Reduction, Arsenic (Pentavalent)<=50 ppb Reduction

    For: Total trihalomethanes (TTHM), Lead, Arsenic

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

  • NSF/ANSI 58

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

    For: Total trihalomethanes (TTHM), Lead, Arsenic

    Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. 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 water filters for lead, ranked

The best reverse osmosis systems, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Interim Enhanced Surface Water Treatment RuleToo many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR)June 1, 2026 to June 30, 2026—Archived
Interim Enhanced Surface Water Treatment RuleToo many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR)May 1, 2026 to May 31, 2026—Archived
Interim Enhanced Surface Water Treatment RuleToo many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR)April 1, 2026 to April 30, 2026—Archived
Interim Enhanced Surface Water Treatment RuleToo many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR)March 1, 2026 to March 31, 2026—Archived
Lead and Copper Rule RevisionsThe required inventory of lead service lines was not completed or submitted on time.EPA: LSL InventoryOct. 17, 2024—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 62 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 Arizona’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Arsenic, fluoride and chromium (total) come from EPA’s file alone, which ends in 2019. Cs Antelope Water Company’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 April 10, 2019 to April 10, 2019.

Testing your own tap

Cs Antelope Water Company’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 2 labs Arizona certifies closest to the area Cs Antelope Water Company serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Fresh Terra Services, LLC.

    Yuma, AZ · about 20 miles

    (928) 257-3601

  • Eurofins Microbiology Laboratories

    Yuma, AZ · about 20 miles

    (928) 317-1127

All 49 certified labs for Arizona

Sources

PWSID AZ0414001. Rebuilt from EPA data on Oct. 18, 2026.

Also in Yuma County

All Arizona utilities

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