Is Trinidad, CA tap water safe?
The short answer
1 of the 5 utilities serving Trinidad has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and California’s records: City of Trinidad.
Westhaven C.S.D., which serves the most people here, has 2 results above the limit’s level with no violation recorded and 2 results above the health goal. The worst: Haloacetic acids (HAA5) at 323 ppb, above the limit’s level, no violation. Health goals are stricter than legal limits and are not enforced.
The water from Westhaven C.S.D. is soft to moderately hard depending on the source, 17 to 120 mg/L (1 to 7 grains per gallon). How California’s water compares.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in Trinidad’s ZIP codes, from EPA’s estimates.
- Open report
Westhaven C.S.D.
California · serves 490 people · under 100 in Trinidad
2 results above the limit’s level with no violation recorded and 2 results above the health goal. The worst: Haloacetic acids (HAA5) at 323 ppb, above the limit’s level, no violation. Hardness: soft to moderately hard depending on the source, 17 to 120 mg/L (1 to 7 grains per gallon).
No health-based violations since 2016
- Open report
City of Trinidad
California · serves 1,072 people · under 100 in Trinidad
1 result above the limit’s level with no violation recorded and 1 result above the health goal. The worst: Total trihalomethanes (TTHM) at 82 ppb, above the limit’s level, no violation. Hardness: soft, 17 mg/L (1 grain per gallon).
1 health-based violation since 2016
- Open report
Big Lagoon CSD
California · serves 112 people · under 100 in Trinidad
1 result above the health goal. The worst: Lead at 4.3 ppb, above the health goal. Hardness: soft, typically 37 mg/L (2.2 grains per gallon).
No health-based violations since 2016
- Open report
Seawood Estates Mutual Water Company
California · serves 63 people · based in Trinidad
1 result above the limit’s level with no violation recorded. The worst: Haloacetic acids (HAA5) at 64.5 ppb, above the limit’s level, no violation.
No health-based violations since 2016
- Open report
Moonstone Heights Mwa
California · serves 33 people · based in Trinidad
1 result above the health goal. The worst: Lead at 2.2 ppb, above the health goal. Hardness: soft, 29 mg/L (1.7 grains per gallon).
No health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in Westhaven C.S.D.’s water, which serves the most people here. Another utility’s report names what handles its own results.
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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: Total trihalomethanes (TTHM), Arsenic, Lead
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: Total trihalomethanes (TTHM), Arsenic, Lead
Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Total trihalomethanes (TTHM), Arsenic, Lead
Water testing near Trinidad
The 2 labs California certifies closest to Trinidad, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Microbac Laboratories, Inc. - Arcata
Arcata, CA · about 13 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts
Humboldt County Public Health Laboratory
Eureka, CA · about 19 miles
Certified for bacteria
ZIP codes in Trinidad
Which ZIP codes are in Trinidad: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: California State Water Resources Control Board, ELAP accredited laboratories and their fields of accreditation; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near Trinidad
Towns nearby with a page of their own.
What to do next
- Read Westhaven C.S.D.’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- About Haloacetic acids (HAA5)What it does to health, where it comes from, and the certification claim that addresses it.About Haloacetic acids (HAA5)
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water