Foothill Mutual Water Company
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
- 32 people
- Connections
- 8
- Water source
- Groundwater
- Based in
- Morgan Hill, CA
- County
- Santa Clara
- Owner
- Private
- Hardness
- Very hard
The ZIP code it serves
The short answer
1 result is above EPA’s legal limit. The worst: Nitrate, above the legal limit. 2 health-based violations since 2016.
What handles itWhat was found
Nitrate, fluoride, total trihalomethanes (TTHM), arsenic, chromium (total) and haloacetic acids (HAA5): California’s own results, samples taken from Jan. 13, 2020 to June 17, 2026, with EPA’s 2012 to 2019 file for earlier years.
Above the legal limit1
Nitrate
Comes from the source
11ppm
Highest sample; found in 121 of 121
2026 average: 7.6 ppm
One sample, in 2023, was above EPA’s legal limit of 10 ppm, at 11 ppm. The next sample at the same point, within 30 days, brought the average back under the limit. In 2026, the latest year on file, its 10 samples averaged 7.6 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 129 ppm, in 2014, and EPA recorded violations in 2015 and 2019.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
Below EPA’s limits2
Fluoride
Forms or is added in treatment
0.13ppm
Highest yearly average, 2020 to 2023
2023, one sample: 0.13 ppm
Averaged by year, the highest was 0.13 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. In 2023, the latest year on file, its one sample was 0.13 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.13 ppm, in 2016.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Total trihalomethanes (TTHM)
Forms or is added in treatment
2.1ppb
Highest yearly average, 2022 to 2025
Averaged by year, the highest was 2.1 ppb, in 2025, 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 3.3 ppb, in 2016.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- 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: Nitrate/Nitrite (30 ppm challenge)
For: Nitrate
- NSF/ANSI 58
Claim: Nitrate/Nitrite Reduction
For: Nitrate
Other certifiers’ wording: 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
Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Nitrate
Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Nitrate
Culligan 10-Cup Pitcher with ZeroWater Technology (ZEROP10)
Pitcher
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
Certified for: Nitrate
Hardness
Very hard, 355 mg/L (20.8 grains per gallon), at its one sampling point, 2020 to 2023.
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.
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Nitrate | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2023 to Dec. 31, 2023 | 11 MG/L | Archived |
| Nitrate | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Aug. 1, 2019 to Aug. 31, 2019 | 12 MG/L | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 18 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Nitrate, fluoride, total trihalomethanes (TTHM), arsenic, chromium (total) and haloacetic acids (HAA5) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Foothill Mutual Water Company’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. 13, 2020 to June 17, 2026.
Testing your own tap
The 3 labs California certifies closest to the area Foothill Mutual Water Company serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Bracewell Engineering, Inc.
Morgan Hill, CA · about 4 miles
Certified for bacteria, nitrate, minerals and other inorganics
CM Analytical, Inc.
Gilroy, CA · about 12 miles
Certified for bacteria
Torrent Laboratory, Inc
Milpitas, CA · about 23 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, PFAS
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- California State Water Resources Control Board, Division of Drinking Water, results from Jan. 1, 2020 to July 17, 2026, read Oct. 8, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: California State Water Resources Control Board, ELAP accredited laboratories and their fields of accreditation, read Oct. 17, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Hardness: California State Water Resources Control Board, Division of Drinking Water, results from May 13, 2020 to Nov. 16, 2023, read Oct. 10, 2026
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID CA4300630. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on NitrateWhat each one does to health, where it comes from, and the certification claim that addresses it.About Nitrate
- Get the utility’s own reportFoothill Mutual Water Company must send you a water quality report every year. It covers contaminants this page does not show.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Compare certified filtersWhat the filters certified for these results cost over five years, cartridges included.Compare five-year costs