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Oasis Property Owners Association

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
100 people
Connections
39
Water source
Groundwater
Based in
Bakersfield, CA
County
Kern
Owner
Private
Hardness
Moderately hard
The ZIP code it serves

93307

The short answer

1 result is above the limit’s level with no violation recorded, and 1 more is above the health goal. The worst: Arsenic, above the limit’s level, no violation. 13 health-based violations since 2016.

What handles it

What was found

Arsenic, nitrate, chromium (total), fluoride, total trihalomethanes (TTHM) and haloacetic acids (HAA5): California’s own results, samples taken from Feb. 5, 2020 to April 21, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the limit’s level, no violation recorded1

Arsenic

Comes from the source

Above the limit’s level, no violation

15.5ppb

Highest yearly average, 2020 to 2026

2026 average: 8.8 ppb

Averaged by year, the highest was 15.5 ppb, in 2023, above EPA’s legal limit of 10 ppb. Its highest single sample was 40 ppb. In 2026, the latest year on file, its two samples averaged 8.8 ppb. EPA judges this limit on running averages at each sampling point, and recorded no violation for arsenic 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 11.3 ppb, in 2019, and EPA recorded violations in 2012, 2013, 2014, 2015, 2016, 2017, 2018 and 2019.

What handles it

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

Above the health goal1

Nitrate

Comes from the source

Above the health goal

24ppm

Highest sample; found in 9 of 9

2025, one sample: 1.0 ppm

From 2021 to 2023, two samples were above EPA’s legal limit of 10 ppm, the highest 24 ppm in 2021. Two have no follow-up sample on file within 30 days. 10 ppm is also EPA’s health goal. In 2025, the latest year on file, its one sample was 1.0 ppm. EPA recorded no violation for nitrate at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 12.2 ppm, in 2014.

What handles it

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

Below EPA’s limits3

Chromium (total)

Comes from the source

Below EPA’s limits

55ppb

Highest yearly average, 2022 to 2025

2025: not found

Averaged by year, the highest was 55 ppb, in 2023, below EPA’s legal limit of 100 ppb. Its highest single sample was 110 ppb. In 2025, the latest year on file, it wasn’t found in its one sample. EPA recorded no violation for chromium (total) at this utility since 2020.

What handles it

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.25ppm

Highest yearly average, 2022 to 2025

Averaged by year, the highest was 0.25 ppm, in 2025, 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 0.23 ppm, in 2013.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

1.3ppb

Highest yearly average, 2020 to 2023

2023, one sample: 0.55 ppb

Averaged by year, the highest was 1.3 ppb, in 2020, below EPA’s legal limit of 80 ppb. Its highest single sample was 2.5 ppb. In 2023, the latest year on file, its one sample was 0.55 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.2 ppb, in 2017.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Haloacetic acids (HAA5)
  • 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

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Nitrate/Nitrite (30 ppm challenge)

    For: Arsenic, Nitrate

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

  • NSF/ANSI 58

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Nitrate/Nitrite Reduction

    For: Arsenic, Nitrate

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

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, 102 mg/L (6 grains per gallon), at its one sampling point, 2019 to 2022.

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 6 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Lead and Copper Rule RevisionsThe required inventory of lead service lines was not completed or submitted on time.EPA: LSL InventoryOct. 17, 2024—Addressed
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2019 to June 30, 20190.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2019 to March 31, 20190.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2018 to Dec. 31, 20180.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2018 to Sept. 30, 20180.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2018 to June 30, 20180.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2018 to March 31, 20180.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2017 to Dec. 31, 20170.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2017 to Sept. 30, 20170.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2017 to June 30, 20170.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2017 to March 31, 20170.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2016 to Sept. 30, 20160.011 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2016 to June 30, 20160.011 MG/LArchived
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 1 monitoring or reporting violation not shown.

What this report can’t tell you

  • Everything else. Arsenic, nitrate, chromium (total), fluoride, 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. Oasis Property Owners Association’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 Feb. 5, 2020 to April 21, 2026.

Testing your own tap

Oasis Property Owners Association’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 Oasis Property Owners Association serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Zalco Laboratories, Inc.

    Bakersfield, CA · about 12 miles

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

    (661) 395-0539

  • Pace Analytical Services, LLC dba BC Laboratories, Inc.

    Bakersfield, CA · about 13 miles

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

    (661) 327-4911

  • BSK Associates - Bakersfield Analytical Laboratory

    Bakersfield, CA · about 16 miles

    Certified for bacteria

    (661) 327-0671

All 145 certified labs for California

Sources

PWSID CA1500585. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Kern County

All California utilities

What to do next