Martinez Apartments
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
- 26 people
- Connections
- 9
- Water source
- Groundwater
- Based in
- French Camp, CA
- County
- San Joaquin
- Owner
- Private
- Hardness
- Very hard
The ZIP code it serves
The short answer
2 results are above EPA’s legal limit, and 1 more is above the health goal. The worst: Arsenic, above the legal limit. 27 health-based violations since 2016.
What handles itWhat was found
Arsenic, nitrate, uranium, chromium (total), fluoride and total trihalomethanes (TTHM): California’s own results, samples taken from Jan. 20, 2020 to June 19, 2026, with EPA’s 2012 to 2019 file for earlier years.
Above the legal limit2
Arsenic
Comes from the source
15.3ppb
Highest yearly average, 2020 to 2026
2026 average: 14.5 ppb
Averaged by year, the highest was 15.3 ppb, in 2024, above EPA’s legal limit of 10 ppb. Its highest single sample was 16 ppb. In 2026, the latest year on file, its two samples averaged 14.5 ppb, above the limit. EPA recorded violations for arsenic at this utility in 2023, 2024, 2025 and 2026.
What handles it
- NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
- NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
Nitrate
Comes from the source
13ppm
Highest sample; found in 28 of 28
2026 average: 11.1 ppm
From 2020 to 2026, 21 samples were above EPA’s legal limit of 10 ppm, the highest 13 ppm in 2024. 21 have no follow-up sample on file within 30 days. In 2026, the latest year on file, its two samples averaged 11.1 ppm, above the limit. EPA recorded violations for nitrate at this utility in 2023, 2024 and 2025. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 16.6 ppm, in 2013.
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
Uranium
Comes from the source
11.7ppb
Highest yearly average, 2020 to 2023
2023 average: 10.5 ppb
Averaged by year, the highest was 11.7 ppb, in 2020: below EPA’s legal limit of 30 ppb, but above its health goal of zero. In 2023, the latest year on file, its three samples averaged 10.5 ppb.
What handles it
- NSF/ANSI 58 look for “Uranium”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Chromium (total)
- Fluoride
- Lead
- Total trihalomethanes (TTHM)
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, Uranium
For: Arsenic, Nitrate, Uranium
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
Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Arsenic, 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: Arsenic, Nitrate
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic
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, 235 mg/L (13.7 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 |
|---|---|---|---|---|
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2026 to June 30, 2026 | 15 UG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2026 to June 30, 2026 | 10 MG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2026 to March 31, 2026 | 15 UG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2026 to March 31, 2026 | 10 MG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2025 to Dec. 31, 2025 | 11 MG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2025 to Dec. 31, 2025 | 15 UG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2025 to Sept. 30, 2025 | 11 MG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2025 to Sept. 30, 2025 | 14 UG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2025 to June 30, 2025 | 15 UG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2025 to June 30, 2025 | 12.1 MG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2025 to March 31, 2025 | 12 MG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2025 to March 31, 2025 | 15 UG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2024 to Dec. 31, 2024 | 15 UG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2024 to Dec. 31, 2024 | 12 MG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2024 to Sept. 30, 2024 | 12 MG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2024 to Sept. 30, 2024 | 15 UG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2024 to June 30, 2024 | 15 UG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2024 to June 30, 2024 | 11.1 MG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2024 to March 31, 2024 | 11.3 MG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2024 to March 31, 2024 | 14 UG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2023 to Dec. 31, 2023 | 13.5 UG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Oct. 1, 2023 to Dec. 31, 2023 | 11 MG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2023 to Sept. 30, 2023 | 11.3 MG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2023 to Sept. 30, 2023 | 13.8 UG/L | Archived |
| Arsenic | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2023 to June 30, 2023 | 13.8 UG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | April 1, 2023 to June 30, 2023 | 11.3 MG/L | Archived |
| Nitrate | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2023 to March 31, 2023 | 11.5 MG/L | Archived |
| 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. Arsenic, nitrate, uranium, chromium (total), fluoride and total trihalomethanes (TTHM) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Martinez Apartments’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. 20, 2020 to June 19, 2026.
Testing your own tap
The 3 labs California certifies closest to the area Martinez Apartments serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
San Joaquin County Public Health Laboratory
Stockton, CA · about 5 miles
Certified for bacteria
Fruit Growers Laboratory, Inc.
Stockton, CA · about 5 miles
Certified for bacteria
Precision Enviro-Tech
Stockton, CA · about 8 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics
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 Dec. 15, 2020 to Nov. 15, 2023, read Oct. 10, 2026
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID CA3900751. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 3 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with Arsenic
- Get the utility’s own reportMartinez Apartments 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