Antelope Park 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: 445 people
Connections: 146
Water source: Groundwater
Based in: Lancaster, CA
County: Los Angeles
Owner: Private
Hardness: Varies by source

The ZIP code it serves

93534

The short answer

Nothing in EPA’s and California’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.

What was found

Chromium (total), fluoride, nitrate, total trihalomethanes (TTHM), arsenic, haloacetic acids (HAA5) and uranium: California’s own results, samples taken from March 31, 2020 to April 23, 2026, with EPA’s 2012 to 2019 file for earlier years.

Below EPA’s limits4

Chromium (total)

Comes from the source

Below EPA’s limits

14.5ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 14.5 ppb, in 2026, below EPA’s legal limit of 100 ppb. Its highest single sample was 15 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 16 ppb, in 2019.

What handles it

NSF/ANSI 58 look for “Chromium (Hexavalent) Reduction”
NSF/ANSI 53 look for “Chromium Reduction”

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.3ppm

Highest yearly average, 2020 to 2026

2026 average: 0.3 ppm

Averaged by year, the highest was 0.3 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. In 2026, the latest year on file, its two samples averaged 0.3 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.36 ppm, in 2014.

What handles it

NSF/ANSI 58 look for “Fluoride Reduction”
NSF/ANSI 53 look for “Fluoride”

Nitrate

Comes from the source

Below EPA’s limits

0.7ppm

Highest sample; found in 10 of 17

2026 average: 0.45 ppm

The highest sample, in 2021, was 0.7 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its two samples averaged 0.45 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.6 ppm, in 2019.

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

0.33ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 0.33 ppb, in 2020, below EPA’s legal limit of 80 ppb. Its highest single sample was 1.0 ppb. In 2026, the latest year on file, it wasn’t found in any of its two samples.

What handles it

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

4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.

Arsenic
Haloacetic acids (HAA5)
Lead
Uranium

Hardness

Soft to moderately hard depending on the source, 46 to 87 mg/L (2.7 to 5.1 grains per gallon), across 3 sampling points, 2019 to 2026.

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, salt included Softener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

No health-based violations on file with EPA since 2016.

What this report can’t tell you

Everything else. Chromium (total), fluoride, nitrate, total trihalomethanes (TTHM), arsenic, haloacetic acids (HAA5) and uranium results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Antelope Park 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 March 31, 2020 to April 23, 2026.

Testing your own tap

Antelope Park 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 Antelope Park Mutual Water Company serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

Pat-Chem Laboratories
San Fernando, CA · about 34 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
(800) 400-5227
EMSL Analytical, Inc. (LA Testing)
South Pasadena, CA · about 41 miles
Certified for bacteria, asbestos
(323) 254-9960
Positive Lab Service
Los Angeles, CA · about 48 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts
(213) 745-5312