Skip to content
TapBuff
ZIP

Del Oro River Island Serv Terr #2

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
89 people
Connections
27
Water source
Groundwater
Based in
Chico, CA
County
Tulare
Owner
Private
Hardness
Very hard
The ZIP code it serves

93265

The short answer

1 result is above EPA’s legal limit, and 3 more are above the health goal. The worst: Uranium, above the legal limit. 12 health-based violations since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2007 to 2027.

Uranium, nitrate, arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride and chromium (total): California’s own results, samples taken from Jan. 3, 2020 to June 8, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the legal limit1

Uranium

Comes from the source

Above the legal limit

48.6ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 48.6 ppb, in 2026, above EPA’s legal limit of 30 ppb. Its highest single sample was 62.6 ppb. That was also the latest year on file. EPA recorded a violation for uranium at this utility in 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 29.7 ppb, in 2016, and EPA recorded violations in 2018 and 2019.

What handles it

Above the health goal3

Nitrate

Comes from the source

Above the health goal

13.3ppm

Highest sample; found in 260 of 274

2026 average: 3.2 ppm

From 2020 to 2026, at least 25 samples were above EPA’s legal limit of 10 ppm, the highest 13.3 ppm in 2021. The next sample at the same point, within 30 days, kept the average above the limit for two; 23 have no follow-up sample on file within 30 days. 10 ppm is also EPA’s health goal. In 2026, the latest year on file, its 26 samples averaged 3.2 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 18.2 ppm, in 2012, and EPA recorded violations in 2012, 2013, 2014 and 2019.

What handles it

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

Arsenic

Comes from the source

Above the health goal

9.1ppb

Highest yearly average, 2020 to 2026

2026, one sample: 5.4 ppb

Averaged by year, the highest was 9.1 ppb, in 2020: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 10.9 ppb. In 2026, the latest year on file, its one sample was 5.4 ppb. EPA recorded no violation for arsenic at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 7.7 ppb, in 2019.

What handles it

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

Lead

Comes from pipes, often your own

Above the health goal

1.4ppb

90th percentile, 2025 to 2027

In the latest period, 9 in 10 homes sampled were at or below 1.4 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits3

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

18ppb

Highest yearly average, 2020 to 2024

Averaged by year, the highest was 18 ppb, in 2024, below EPA’s legal limit of 80 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 18 ppb, in 2014.

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

3.8ppb

Highest yearly average, 2020 to 2024

2024, one sample: 2.1 ppb

Averaged by year, the highest was 3.8 ppb, in 2020, below EPA’s legal limit of 60 ppb. In 2024, the latest year on file, its one sample was 2.1 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.9 ppb, in 2015.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.17ppm

Highest yearly average, 2021 to 2024

Averaged by year, the highest was 0.17 ppm, in 2024, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.22 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.5 ppm, in 2012.

What handles it

One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Chromium (total)

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

    For: Nitrate, Arsenic, Lead

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

  • NSF/ANSI 58

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

    For: Uranium, Nitrate, Arsenic, Lead

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

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. 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

The best water filters for lead, ranked

Hardness

Very hard, typically 325 mg/L (19 grains per gallon), across 2 sampling points, 2021 to 2024.

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

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2020 to Dec. 31, 202037 PCI/LResolved
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2020 to June 30, 202037.7 PCI/LResolved
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2020 to March 31, 202038.5 PCI/LResolved
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleOct. 1, 2019 to Dec. 31, 201911 MG/LResolved
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2019 to Dec. 31, 201938 PCI/LResolved
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2019 to Sept. 30, 201937.3 PCI/LResolved
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2019 to June 30, 201937 PCI/LResolved
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2019 to March 31, 201936.5 PCI/LResolved
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2018 to Dec. 31, 201838.5 PCI/LResolved
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2018 to Sept. 30, 201836 PCI/LResolved
Combined UraniumThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2018 to June 30, 201835.3 PCI/LResolved
Coliform (TCR)Too many samples in a month tested positive for coliform bacteria.EPA: Maximum Contaminant Level Violation, Monthly (TCR)Feb. 1, 2016 to Feb. 29, 2016—Resolved
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. Uranium, nitrate, arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride and chromium (total) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Del Oro River Island Serv Terr #2’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. 3, 2020 to June 8, 2026.

Testing your own tap

Del Oro River Island Serv Terr #2’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 Del Oro River Island Serv Terr #2 serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Sierra Dairy Laboratory

    Tulare, CA · about 36 miles

    Certified for bacteria

    (559) 686-2070

  • Fruit Growers Laboratory, Inc.

    Visalia, CA · about 40 miles

    Certified for bacteria

    (559) 734-9473

  • Inyo County Water Lab

    Independence, CA · about 47 miles

    Certified for bacteria

    (760) 878-8476

All 145 certified labs for California

Sources

PWSID CA5402048. Rebuilt from EPA data on Oct. 18, 2026.

Also in Tulare County

All California utilities

What to do next