Skip to content
TapBuff
ZIP

MD 05 Mountain Ranches

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
239 people
Connections
27
Water source
Groundwater
Based in
Madera, CA
County
Madera
Owner
Local government
Hardness
Hard
The ZIP code it serves

93636

The short answer

1 result is above EPA’s legal limit, and 1 more is above the health goal. The worst: Nitrate, above the legal limit. 1 health-based violation since 2016.

What handles it

What was found

Nitrate, arsenic, total trihalomethanes (TTHM), fluoride, haloacetic acids (HAA5) and chromium (total): California’s own results, samples taken from Jan. 7, 2020 to April 6, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the legal limit1

Nitrate

Comes from the source

Above the legal limit

15ppm

Highest sample; found in 47 of 47

2026 average: 9.1 ppm

From 2020 to 2026, four samples were above EPA’s legal limit of 10 ppm, the highest 15 ppm in 2023. One came back under the limit on the next sample at the same point and three have no follow-up sample on file within 30 days. In 2026, the latest year on file, its two samples averaged 9.1 ppm. EPA recorded a violation for nitrate at this utility in 2023. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 9.1 ppm, in 2018.

What handles it

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

Above the health goal1

Arsenic

Comes from the source

Above the health goal

6.8ppb

Highest yearly average, 2020 to 2025

2025 average: 5.0 ppb

Averaged by year, the highest was 6.8 ppb, in 2020: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 7.7 ppb. In 2025, the latest year on file, its two samples averaged 5.0 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 8.1 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”

Below EPA’s limits3

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

20ppb

Highest yearly average, 2023 to 2024

2024 average: 3.0 ppb

Averaged by year, the highest was 20 ppb, in 2023, below EPA’s legal limit of 80 ppb. In 2024, the latest year on file, its three samples averaged 3.0 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 22 ppb, in 2019.

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

0.99ppm

Highest yearly average, 2021 to 2024

Averaged by year, the highest was 0.99 ppm, in 2024, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 1.5 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.1 ppm, in 2015.

What handles it

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

4.8ppb

Highest yearly average, 2023 to 2024

2024: not found

Averaged by year, the highest was 4.8 ppb, in 2023, below EPA’s legal limit of 60 ppb. In 2024, 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 3.7 ppb, in 2019.

What handles it

No certification claim covers this compound yet.

2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Chromium (total)
  • 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: Nitrate/Nitrite (30 ppm challenge), Arsenic (Pentavalent)<=50 ppb Reduction

    For: Nitrate, Arsenic

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

  • NSF/ANSI 58

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

    For: Nitrate, Arsenic

    Other certifiers’ wording: Nitrate; 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

Hard, typically 160 mg/L (9.4 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 9.4 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJan. 1, 2023 to March 31, 202315 MG/LResolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record.

What this report can’t tell you

  • Everything else. Nitrate, arsenic, total trihalomethanes (TTHM), fluoride, haloacetic acids (HAA5) and chromium (total) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. MD 05 Mountain Ranches’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. 7, 2020 to April 6, 2026.

Testing your own tap

MD 05 Mountain Ranches’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 MD 05 Mountain Ranches serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • SGS North America, Inc.

    Clovis, CA · about 15 miles

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

    (559) 862-2118

  • Dellavalle Laboratory, Inc.

    Fresno, CA · about 15 miles

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

    (559) 233-6129

  • Moore Twining Associates, Inc.

    Fresno, CA · about 18 miles

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

    (559) 268-7021

All 145 certified labs for California

Sources

PWSID CA2000549. Rebuilt from EPA data on Oct. 18, 2026.

Also in Madera County

All California utilities

What to do next