Public water system · CA1210018

Active

Trinidad, City of

At a glance

City of Trinidad (PWSID CA1210018) is an active community water system in Humboldt County, California. It reports serving 1,072 people through 324 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in April 2024.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

1,072

Service connections

324

Primary source

Surface water

System type

CWS

Community water system

System record

PWSIDCA1210018

System typeCommunity water system

Activity statusActive

Population served1,072

Service connections324

Primary water sourceSurface water

Owner typeLocal government

Primacy agencyCA state drinking water program

City servedTrinidad

StateCalifornia

ZIP—

CountyHumboldt County

How does City of Trinidad compare with other water systems in Humboldt County?

By EPA's size categories, City of Trinidad is a small system (501 to 3,300 people). Humboldt County has 90 active public water systems. Its population served is about 28% below the county average of 1,486 people per system, and accounts for 0.8% of the 133,779 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active community water system reports serving 6,703 people, so City of Trinidad is well below that figure.

What does “community water system” mean?

A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. California has 2,997 active community water systems, 40% of the state's 7,479 active systems. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 609 California systems (8.1%) list surface water as their primary source.

Who owns and regulates City of Trinidad?

EPA lists City of Trinidad as owned by a local government. The CA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 33 of the 90 active systems in Humboldt County (37%) are also owned by a local government.

Does City of Trinidad have drinking water violations?

Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in April 2024. The violations listed here began between June 1993 and April 2024. By type: 4 contaminant level above the legal limit, 3 monitoring and reporting, 2 monitoring, 2 required treatment not met and 1 disinfectant level above the legal limit. The contaminant or rule involved most often is Haloacetic acids (HAA5) (4 of them). EPA lists 12 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.

Began	Violation	Contaminant or rule	Health-based	Status
2024-04-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2020-10-01	Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52	Lead and Copper Rulecode 5000	No	Resolved
2019-10-01	Disinfectant level above the legal limitNon-Acute MRDL · code 11	Chlorinecode 0999	Yes	Resolved
2019-06-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2014-10-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Haloacetic acids (HAA5)code 2456	Yes	Resolved
2010-10-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Haloacetic acids (HAA5)code 2456	Yes	Resolved
2010-04-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Haloacetic acids (HAA5)code 2456	Yes	Resolved
2009-04-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Haloacetic acids (HAA5)code 2456	Yes	Resolved
2001-08-01	Required treatment not metTreatment Technique (SWTR and GWR) · code 41	Surface Water Treatment Rulecode 0200	Yes	Resolved
1994-01-01	Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36	Surface Water Treatment Rulecode 0200	No	Resolved
1993-07-01	Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51	Lead and Copper Rulecode 5000	No	Resolved
1993-06-01	Required treatment not metTreatment Technique (SWTR and GWR) · code 41	Surface Water Treatment Rulecode 0200	Yes	Resolved

The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.

City of Trinidad: frequently asked questions

Who runs City of Trinidad?

City of Trinidad (PWSID CA1210018) is a community water system owned by a local government. It is regulated by the CA state drinking water program.

How many people does City of Trinidad serve?

City of Trinidad reports serving 1,072 people through 324 service connections in Humboldt County, California.

Where does City of Trinidad get its water?

EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.

Does City of Trinidad have any drinking water violations?

Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in April 2024. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.

Is City of Trinidad's water safe to drink?

AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in April 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.

Where can I find City of Trinidad's water quality report?

As a community water system, City of Trinidad must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.

Other water systems in Humboldt County

Water system	County	Population served	Type	Source
Eureka, City of	Humboldt	27,078	Community	Purchased groundwater
Arcata, City of	Humboldt	20,875	Community	Purchased groundwater
Humboldt C.S.D.	Humboldt	19,807	Community	Groundwater
Mckinleyville C.S.D.	Humboldt	16,900	Community	Purchased groundwater
Fortuna, City of	Humboldt	12,133	Community	Groundwater
Rio Dell, City of	Humboldt	3,300	Community	Surface water

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About this data

Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.

Cite as: AquaCensus, “Trinidad, City of, PWSID CA1210018, California”, https://aquacensus.com/water-systems/california/trinidad-city-of-ca1210018 (data as of October 1, 2026).