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Yolo Co Housing Authority - El Rio Villa

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
432 people
Connections
13
Water source
Groundwater
Based in
Woodland, CA
County
Yolo
Owner
Local government
Hardness
Varies by source
The ZIP code it serves

95694

The short answer

2 results are 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, nitrate, chromium (total), total trihalomethanes (TTHM), fluoride and haloacetic acids (HAA5): California’s own results, samples taken from Jan. 23, 2020 to July 6, 2026, with EPA’s 2012 to 2019 file for earlier years.

Uranium: EPA’s compliance monitoring file, samples taken from July 5, 2017 to Feb. 20, 2019. Newer results are in the utility’s annual water quality report.

Above the health goal2

Arsenic

Comes from the source

Above the health goal

2.3ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 2.3 ppb, in 2025: below EPA’s legal limit of 10 ppb, but above its health goal of zero. In 2026, 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 1.9 ppb, in 2018.

What handles it

  • NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
  • NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”

Uranium

Comes from the source

Above the health goal

0.35ppb

Highest yearly average, 2017 to 2019

Averaged by year, the highest was 0.35 ppb, in 2019: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That was also the latest year on file.

What handles it

Below EPA’s limits5

Nitrate

Comes from the source

Below EPA’s limits

7.3ppm

Highest sample; found in 13 of 13

2026, one sample: 7.3 ppm

The highest sample, in 2026, was 7.3 ppm, below EPA’s legal limit of 10 ppm. That was also the latest year on file, and its one sample was 7.3 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 7.9 ppm, in 2012.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

Chromium (total)

Comes from the source

Below EPA’s limits

26ppb

Highest yearly average, 2020 to 2026

2026, one sample: 14 ppb

Averaged by year, the highest was 26 ppb, in 2025, below EPA’s legal limit of 100 ppb. In 2026, the latest year on file, its one sample was 14 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 25 ppb, in 2018.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

6.0ppb

Highest yearly average, 2020 to 2024

Averaged by year, the highest was 6.0 ppb, in 2024, below EPA’s legal limit of 80 ppb. Its highest single sample was 10 ppb. That was also the latest year on file.

What handles it

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

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.19ppm

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 0.19 ppm, in 2026, below EPA’s legal limit of 4.0 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.58 ppm, in 2019.

What handles it

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

1.4ppb

Highest yearly average, 2021 to 2024

2024 average: 0.7 ppb

Averaged by year, the highest was 1.4 ppb, in 2021, below EPA’s legal limit of 60 ppb. Its highest single sample was 1.6 ppb. In 2024, the latest year on file, its two samples averaged 0.7 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.4 ppb, in 2018.

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

    For: Arsenic, Uranium

    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, 90 to 270 mg/L (5.3 to 15.8 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 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 is 1 monitoring or reporting violation: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Arsenic, nitrate, chromium (total), total trihalomethanes (TTHM), fluoride and haloacetic acids (HAA5) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Uranium comes from EPA’s file alone, which ends in 2019. Yolo Co Housing Authority - El Rio Villa’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; California’s results run from Jan. 23, 2020 to July 6, 2026; EPA’s compliance samples are from July 5, 2017 to Feb. 20, 2019.

Testing your own tap

Yolo Co Housing Authority - El Rio Villa’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 Yolo Co Housing Authority - El Rio Villa serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Napa-Solano-Yolo-Marin Public Health Laboratory

    Fairfield, CA · about 23 miles

    Certified for bacteria

    (707) 784-4410

  • Caltest Analytical Laboratory

    Napa, CA · about 26 miles

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

    (707) 258-4000

  • Eurofins Sacramento Service Center

    West Sacramento, CA · about 27 miles

    Certified for bacteria, nitrate, minerals and other inorganics

    (626) 386-1221

All 145 certified labs for California

Sources

PWSID CA5700615. Rebuilt from EPA data on Oct. 18, 2026.

Also in Yolo County

All California utilities

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