Callahan Water District
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
- 70 people
- Connections
- 33
- Water source
- Surface water
- Based in
- Callahan, CA
- County
- Siskiyou
- Owner
- Local government
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
Total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate: California’s own results, samples taken from July 6, 2020 to July 11, 2022, with EPA’s 2012 to 2019 file for earlier years.
Arsenic, chromium (total) and fluoride: EPA’s compliance monitoring file, samples taken from May 7, 2018 to June 3, 2019. Newer results are in the utility’s annual water quality report.
Below EPA’s limits3
Total trihalomethanes (TTHM)
Forms or is added in treatment
24.3ppb
Highest yearly average, 2020 to 2022
Averaged by year, the highest was 24.3 ppb, in 2022, 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 13.2 ppb, in 2018.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Haloacetic acids (HAA5)
Forms or is added in treatment
15.7ppb
Highest yearly average, 2020 to 2022
Averaged by year, the highest was 15.7 ppb, in 2022, below EPA’s legal limit of 60 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 8.1 ppb, in 2018.
What handles it
No certification claim covers this compound yet.
Nitrate
Comes from the source
0.16ppm
Highest sample; found in 1 of 3
2022, one sample: 0.16 ppm
The highest sample, in 2022, was 0.16 ppm, below EPA’s legal limit of 10 ppm. That was also the latest year on file, and its one sample was 0.16 ppm.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Fluoride
- Lead
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Long Term 2 Enhanced Surface Water Treatment Rule | Water drawn from a river, lake or reservoir was not filtered as required.EPA: Failure to Filter (SWTR) | Oct. 10, 2016 | — | Resolved |
| 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. Total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate results here are California’s own from 2020 on, with EPA’s national file for 2012 to 2019. Arsenic, chromium (total) and fluoride come from EPA’s file alone, which ends in 2019. Callahan Water District’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 6, 2020 to July 11, 2022; EPA’s compliance samples are from May 7, 2018 to June 3, 2019.
Testing your own tap
The 2 labs California certifies closest to the area Callahan Water District serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Pace Analytical Services, LLC - Redding
Redding, CA · about 56 miles
Certified for bacteria
Microbac Laboratories, Inc. - Arcata
Arcata, CA · about 73 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
- 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 CA4700503. 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 reportCallahan Water District 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