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Butterfield Ranch

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
350 people
Connections
308
Water source
Groundwater
Based in
San Diego, CA
County
San Diego
Owner
Private
Hardness
Very hard
The ZIP code it serves

92036

The short answer

2 results are above the health goal. The worst: Uranium, above the health goal. 4 health-based violations since 2016.

What handles it

What was found

Uranium, arsenic, fluoride, nitrate, chromium (total), total trihalomethanes (TTHM) and haloacetic acids (HAA5): California’s own results, samples taken from July 20, 2020 to April 3, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal2

Uranium

Comes from the source

Above the health goal

10.4ppb

Highest yearly average, 2021 to 2025

Averaged by year, the highest was 10.4 ppb, in 2025: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 25.3 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 19.4 ppb, in 2016.

What handles it

Arsenic

Comes from the source

Above the health goal

0.5ppb

Highest yearly average, 2020 to 2024

2024: not found

Averaged by year, the highest was 0.5 ppb, in 2020: below EPA’s legal limit of 10 ppb, but above its health goal of zero. In 2024, the latest year on file, it wasn’t found in any of its two samples.

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

Fluoride

Forms or is added in treatment

Below EPA’s limits

2.8ppm

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 2.8 ppm, in 2026, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 2.9 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.0 ppm, in 2014.

What handles it

Nitrate

Comes from the source

Below EPA’s limits

1.7ppm

Highest sample; found in 7 of 10

2026: not found

The highest sample, in 2024, was 1.7 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, it wasn’t found in any of its two samples. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 1.1 ppm, in 2013.

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

1.0ppb

Highest yearly average, 2020 to 2024

2024: not found

Averaged by year, the highest was 1.0 ppb, in 2020, below EPA’s legal limit of 100 ppb. In 2024, the latest year on file, it wasn’t found in any of its two samples.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

0.6ppb

Highest yearly average, 2021 to 2025

2025 average: 0.4 ppb

Averaged by year, the highest was 0.6 ppb, in 2024, below EPA’s legal limit of 80 ppb. Its highest single sample was 2.1 ppb. In 2025, the latest year on file, its eight samples averaged 0.4 ppb.

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

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

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

  • NSF/ANSI 58

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

    For: Uranium, 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

Very hard, typically 446 mg/L (26.1 grains per gallon), across 2 sampling points, 2020 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 26.1 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—Unaddressed
Revised Total Coliform RuleE. coli was confirmed in the water system.EPA: Maximum Contaminant Level Violation, E. coli (RTCR)July 1, 2022 to July 31, 2022—Resolved
Revised Total Coliform RuleE. coli was confirmed in the water system.EPA: Maximum Contaminant Level Violation, E. coli (RTCR)June 1, 2022 to June 30, 2022—Resolved
Revised Total Coliform RuleE. coli was confirmed in the water system.EPA: Maximum Contaminant Level Violation, E. coli (RTCR)May 1, 2022 to May 31, 2022—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 9 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Uranium, arsenic, fluoride, nitrate, chromium (total), 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. Butterfield Ranch’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 July 20, 2020 to April 3, 2026.

Testing your own tap

Butterfield Ranch’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 Butterfield Ranch serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • EMSL Analytical, Inc.

    San Diego, CA · about 40 miles

    Certified for bacteria

    (800) 220-3675

  • Analytical Environmental Lab, LLC

    San Diego, CA · about 40 miles

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

    (619) 871-8505

  • Environmental Laboratory Network, Inc.

    San Diego, CA · about 41 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, radioactivity

    (858) 266-1666

All 145 certified labs for California

Sources

PWSID CA3701184. Rebuilt from EPA data on Oct. 18, 2026.

Also in San Diego County

All California utilities

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