Skip to content
TapBuff
ZIP

Amarillo Mutual Water Company

What EPA’s and California’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
3,134 people
Connections
625
Water source
Groundwater
Based in
Rosemead, CA
County
Los Angeles
Owner
Local government
Hardness
Very hard
The ZIP code it serves

91770

The short answer

2 results are above the health goal. The worst: Uranium, above the health goal. No health-based violations on file since 2016.

What handles it

What was found

Uranium, arsenic, nitrate, fluoride, chromium (total), total trihalomethanes (TTHM) and haloacetic acids (HAA5): California’s own results, samples taken from Jan. 21, 2020 to Dec. 13, 2025, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal2

Uranium

Comes from the source

Above the health goal

21ppb

Highest yearly average, 2020 to 2025

2025 average: 20 ppb

Averaged by year, the highest was 21 ppb, in 2024: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 31.3 ppb. In 2025, the latest year on file, its 14 samples averaged 20 ppb. EPA recorded no violation for uranium at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 15.3 ppb, in 2018.

What handles it

Arsenic

Comes from the source

Above the health goal

0.44ppb

Highest yearly average, 2020 to 2023

2023: not found

Averaged by year, the highest was 0.44 ppb, in 2021: below EPA’s legal limit of 10 ppb, but above its health goal of zero. In 2023, the latest year on file, it wasn’t found in any of its two samples.

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 limits5

Nitrate

Comes from the source

Below EPA’s limits

7.1ppm

Highest sample; found in 200 of 200

2025 average: 4.6 ppm

The highest sample, in 2024, was 7.1 ppm, below EPA’s legal limit of 10 ppm. In 2025, the latest year on file, its 98 samples averaged 4.6 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 5.3 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

0.68ppm

Highest yearly average, 2020 to 2023

Averaged by year, the highest was 0.68 ppm, in 2023, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.73 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.76 ppm, in 2019.

What handles it

Chromium (total)

Comes from the source

Below EPA’s limits

7.8ppb

Highest yearly average, 2020 to 2023

2023 average: 6.1 ppb

Averaged by year, the highest was 7.8 ppb, in 2021, below EPA’s legal limit of 100 ppb. In 2023, the latest year on file, its two samples averaged 6.1 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 5.5 ppb, in 2016.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

4.3ppb

Highest yearly average, 2020 to 2025

2025: not found

Averaged by year, the highest was 4.3 ppb, in 2021, below EPA’s legal limit of 80 ppb. Its highest single sample was 22 ppb. In 2025, the latest year on file, it wasn’t found in any of its 117 samples. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.8 ppb, in 2018.

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

2.0ppb

Highest yearly average, 2020 to 2025

2025: not found

Averaged by year, the highest was 2.0 ppb, in 2021, below EPA’s legal limit of 60 ppb. Its highest single sample was 8.0 ppb. In 2025, the latest year on file, it wasn’t found in any of its two samples.

What handles it

No certification claim covers this compound yet.

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

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

    For: Uranium, 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

Hardness

Very hard, typically 240 mg/L (14 grains per gallon), across 2 sampling points, 2019 to 2023.

Hardness is calcium and magnesium. EPA sets no limit for it: it shows up as scale on fixtures and in water heaters, and as soap that won’t lather. USGS calls water above 60 mg/L moderately hard, above 120 hard and above 180 very hard.

Softeners compared at 14 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

No health-based violations on file with EPA since 2016. There are 15 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Uranium, arsenic, nitrate, fluoride, chromium (total), total trihalomethanes (TTHM) and haloacetic acids (HAA5) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Amarillo Mutual Water Company’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; California’s results run from Jan. 21, 2020 to Dec. 13, 2025.

Testing your own tap

Amarillo Mutual 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 California certifies.

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

  • EMSL Analytical, Inc. (LA Testing)

    South Pasadena, CA · about 6 miles

    Certified for bacteria, asbestos

    (323) 254-9960

  • Weck Laboratories, Inc.

    City of Industry, CA · about 7 miles

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

    (626) 336-2139

  • Michelson Laboratories, Inc.

    Commerce, CA · about 7 miles

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

    (562) 928-0553

All 145 certified labs for California

Sources

PWSID CA1910002. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Los Angeles County

All California utilities

What to do next