Skip to content
TapBuff
ZIP

Cal American - Yerba Buena

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
690 people
Connections
232
Water source
Groundwater
Based in
Rosemead, CA
County
Ventura
Owner
Private
Hardness
Varies by source
The ZIP code it serves

90265

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, chromium (total), fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5), nitrate and uranium: California’s own results, samples taken from Jan. 15, 2020 to March 17, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Arsenic

Comes from the source

Above the health goal

7.0ppb

Highest yearly average, 2020 to 2025

2025: not found

Averaged by year, the highest was 7.0 ppb, in 2022: below EPA’s legal limit of 10 ppb, but above its health goal of zero. In 2025, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.5 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 limits4

Chromium (total)

Comes from the source

Below EPA’s limits

24ppb

Highest yearly average, 2020 to 2025

2025: not found

Averaged by year, the highest was 24 ppb, in 2022, below EPA’s legal limit of 100 ppb. Its highest single sample was 25 ppb. In 2025, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 6.0 ppb, in 2018.

What handles it

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.9ppm

Highest yearly average, 2020 to 2025

Averaged by year, the highest was 0.9 ppm, in 2025, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 1.1 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.9 ppm, in 2016.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

6.5ppb

Highest yearly average, 2020 to 2025

2025: not found

Averaged by year, the highest was 6.5 ppb, in 2020, below EPA’s legal limit of 80 ppb. Its highest single sample was 13 ppb. In 2025, the latest year on file, it wasn’t found in any of its five samples. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 7.0 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

4.0ppb

Highest yearly average, 2020 to 2025

2025: not found

Averaged by year, the highest was 4.0 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2025, the latest year on file, it wasn’t found in its one sample. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.0 ppb, in 2013.

What handles it

No certification claim covers this compound yet.

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

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

Hardness

Moderately hard to very hard depending on the source, 120 to 476 mg/L (7 to 27.8 grains per gallon), across 5 sampling points, 2019 to 2025.

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 includedSoftener 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. Arsenic, chromium (total), fluoride, total trihalomethanes (TTHM), haloacetic acids (HAA5), nitrate and uranium results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Cal American - Yerba Buena’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. 15, 2020 to March 17, 2026.

Testing your own tap

Cal American - Yerba Buena’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 Cal American - Yerba Buena serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Camrosa Water District Wastewater Laboratory

    Camarillo, CA · about 14 miles

    Certified for bacteria

    (805) 248-0402

  • Ventura County Public Health Laboratory

    Oxnard, CA · about 20 miles

    Certified for bacteria

    (805) 981-5131

  • Fruit Growers Laboratory, Inc.

    Santa Paula, CA · about 23 miles

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

    (805) 392-2000

All 145 certified labs for California

Sources

PWSID CA5610006. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Ventura County

All California utilities

What to do next