Woodson Bridge MHP
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
- 158 people
- Connections
- 105
- Water source
- Groundwater
- Based in
- Silverdale, CA
- County
- Tehama
- Owner
- Private
The ZIP code it serves
The short answer
Nothing in EPA’s and California’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. 1 health-based violation since 2016.
What was found
Nitrate, chromium (total), arsenic and total trihalomethanes (TTHM): California’s own results, samples taken from July 17, 2020 to Aug. 6, 2025, with EPA’s 2012 to 2019 file for earlier years.
Fluoride: EPA’s compliance monitoring file, samples taken from July 10, 2018 to July 10, 2018. Newer results are in the utility’s annual water quality report.
Below EPA’s limits2
Nitrate
Comes from the source
1.4ppm
Highest sample; found in 6 of 6
2025, one sample: 1.2 ppm
The highest sample, in 2020, was 1.4 ppm, below EPA’s legal limit of 10 ppm. In 2025, the latest year on file, its one sample was 1.2 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 2.5 ppm, in 2012.
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
11ppb
Highest yearly average, 2022 to 2025
Averaged by year, the highest was 11 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”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Fluoride
- Lead
- Total trihalomethanes (TTHM)
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Lead and Copper Rule Revisions | The required inventory of lead service lines was not completed or submitted on time.EPA: LSL Inventory | Oct. 17, 2024 | — | Unaddressed |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 2 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Nitrate, chromium (total), arsenic and total trihalomethanes (TTHM) results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride comes from EPA’s file alone, which ends in 2019. Woodson Bridge MHP’s own annual report, which it must send you every year, has newer results for those and 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 17, 2020 to Aug. 6, 2025; EPA’s compliance samples are from July 10, 2018 to July 10, 2018.
Testing your own tap
The 3 labs California certifies closest to the area Woodson Bridge MHP serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Fruit Growers Laboratory, Inc.
Chico, CA · about 25 miles
Certified for bacteria
Pace Analytical Services, LLC - Redding
Redding, CA · about 46 miles
Certified for bacteria
Alpha Analytical Laboratories, Inc. - Ukiah
Ukiah, CA · about 73 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity
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
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID CA5200551. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and California’s records for this utility. They don’t cover everything, which is why the next step matters.Every contaminant TapBuff tracks
- Get the utility’s own reportWoodson Bridge MHP must send you a water quality report every year. It covers contaminants this page does not show, and has newer results than EPA’s national file for the ones here that come from it.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
- Decide if you want a filter at allA filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.NSF/ANSI standards, decoded