Oak Grove Mobile Home Park
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
- 109 people
- Connections
- 31
- Water source
- Groundwater
- Based in
- Bell Canyon, CA
- County
- Los Angeles
- Owner
- Private
- Hardness
- Very hard
The ZIP code it serves
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 itWhat was found
Nitrate, uranium, chromium (total), fluoride, arsenic and total trihalomethanes (TTHM): California’s own results, samples taken from Oct. 5, 2020 to May 14, 2026.
Above the legal limit1
Nitrate
Comes from the source
11.1ppm
Highest sample; found in 38 of 38
2026 average: 6.7 ppm
In 2023, two samples were above EPA’s legal limit of 10 ppm, the highest 11.1 ppm. The next sample at the same point, within 30 days, kept the average above the limit for one; one has no follow-up sample on file within 30 days. In 2026, the latest year on file, its two samples averaged 6.7 ppm. EPA recorded a violation for nitrate at this utility in 2023.
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
6.7ppb
Highest yearly average, 2022 to 2025
2025, one sample: 6.5 ppb
Averaged by year, the highest was 6.7 ppb, in 2022: below EPA’s legal limit of 30 ppb, but above its health goal of zero. In 2025, the latest year on file, its one sample was 6.5 ppb.
What handles it
- NSF/ANSI 58 look for “Uranium”
Below EPA’s limits2
Chromium (total)
Comes from the source
27ppb
Highest yearly average, 2022 to 2025
Averaged by year, the highest was 27 ppb, in 2025, below EPA’s legal limit of 100 ppb. That was also the latest year on file.
What handles it
- NSF/ANSI 58 look for “Chromium (Hexavalent) Reduction”
- NSF/ANSI 53 look for “Chromium Reduction”
Fluoride
Forms or is added in treatment
0.3ppm
Highest yearly average, 2022 to 2025
2025, one sample: 0.3 ppm
Averaged by year, the highest was 0.3 ppm, in 2022, below EPA’s legal limit of 4.0 ppm. In 2025, the latest year on file, its one sample was 0.3 ppm.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- 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
Claim: Nitrate/Nitrite (30 ppm challenge)
For: Nitrate
- NSF/ANSI 58
Claims: Nitrate/Nitrite Reduction, Uranium
For: Nitrate, Uranium
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, 462 mg/L (27 grains per gallon), at its one sampling point, 2022 to 2025.
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 | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | Jan. 1, 2023 to Dec. 31, 2023 | 11.1 MG/L | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 3 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Nitrate, uranium, chromium (total), fluoride, arsenic and total trihalomethanes (TTHM) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Oak Grove Mobile Home Park’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 Oct. 5, 2020 to May 14, 2026.
Testing your own tap
The 3 labs California certifies closest to the area Oak Grove Mobile Home Park serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Pat-Chem Laboratories
San Fernando, CA · about 18 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
EMSL Analytical, Inc. (LA Testing)
South Pasadena, CA · about 33 miles
Certified for bacteria, asbestos
Positive Lab Service
Los Angeles, CA · about 37 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts
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
- 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 Aug. 26, 2022 to Aug. 14, 2025, read Oct. 10, 2026
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID CA1900537. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 2 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with Nitrate
- Get the utility’s own reportOak Grove Mobile Home Park 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