Is Trinidad, CA Tap Water Safe to Drink?
Graded D — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
45/100
waterverge.com Trinidad, CA — Water Quality Report
Trinidad's drinking water received a grade of D (45 out of 100), indicating poor water quality. The city's 7 water systems serve approximately 1,994 residents using surface water.
Lead levels were measured at 0.9 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 500 violations on record, including 30 health-based violations. 39 remain unresolved.
What to know about Trinidad's water
Trinidad ranks #641 out of 694 cities in California for water quality, placing it among the lowest-rated in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
As a small community water system, Trinidad may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 25 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Trinidad, CA water safe to drink?
Trinidad's drinking water has significant quality concerns based on EPA testing data. With a grade of D (45/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 7 water systems serve approximately 1,994 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Trinidad
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Trinidad's water quality assessment. Grade: D (45/100).
Contaminants: Revised Total Coliform Rule.
Contaminants: Public Notice.
Contaminants: Revised Total Coliform Rule, Nitrate.
Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4683). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Trinidad's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Trinidad's water system has 500 total violations on record, including 30 health-based violations. 39 remain unresolved. 25 violations were issued in the last 5 years.
Flood & environmental risk
Humboldt County has experienced 10 federally declared disasters since 1974. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Mad R Nr Arcata, Little R Nr Trinidad.
Where does Trinidad's water come from?
Trinidad's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 7 water systems serving approximately 1,994 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Mad R Nr Arcata (river), Little R Nr Trinidad (river).
What Trinidad residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Trinidad's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Trinidad's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Flood & disaster history
Humboldt County has experienced 10 federally declared disasters since 1974. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Trinidad's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.9 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.55 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Trinidad compares by contaminant
Explore where Trinidad ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Trinidad's water comes from
Trinidad's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by local government ownership and serves approximately 1,994 people through 7 water systems.
Water bodies near Trinidad
Trinidad is located near 2 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Trinidad
| System Name | PWSID | Population | Source |
|---|---|---|---|
| TRINIDAD, CITY OF | CA1210018 | 1,072 | SW |
| WESTHAVEN C.S.D. | CA1210024 | 490 | SW |
| WISEMANS MOBILE COURT | OR4100431 | 114 | GW |
| BIG LAGOON CSD | CA1200592 | 112 | GW |
| LAKESIDE MOBILE HOME & RV PARK | OR4100450 | 110 | GW |
| SEAWOOD ESTATES MUTUAL WATER COMPANY | CA1200588 | 63 | SW |
| MOONSTONE HEIGHTS MWA | CA1200590 | 33 | GW |
How Trinidad compares
Full California rankings →Trinidad's score of 45/100 is below the average of 57/100 among major California cities. It outscores 5 of 10 nearby cities.
Nearby cities
View California rankings →About Trinidad, CA
Wikipedia →Trinidad is a seaside city in Humboldt County, California, located on the Pacific Ocean 8 miles (13 km) north of the Arcata-Eureka Airport and 15 miles (24 km) north of the college town of Arcata. Trinidad is noted for its coastline, with ten public beaches and offshore rocks, part of the California Coastal National Monument, of which Trinidad is a "Gateway City." Fishing operations related to Trinidad Harbor are vital to both local tourism and commercial fishing interests in the region. Situated at an elevation of 174 feet (53 m) above its own North Coast harbor, Trinidad is one of California's smallest incorporated cities by population, with 307 residents in 2020, down from 367 residents in 2010.
Learn more about your water
Guides and resources related to Trinidad's water quality findings.
Explore water quality across Humboldt
Frequently asked questions
Is Trinidad, CA tap water safe to drink?
Trinidad's water quality earned a grade of D (45/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #641 out of 694 cities tested in California.
What contaminants are in Trinidad's water?
Lead was measured at 0.9 ppb (90th percentile). 500 violations are on record.
How is Trinidad's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Trinidad?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Trinidad's water come from?
Trinidad's water is sourced from Surface water. The city has 7 water systems serving approximately 1,994 residents.
What health violations has Trinidad's water system had?
Trinidad has 30 health-based violations on record. The most recent violation was recorded in November 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 39 violations remain unresolved.
How does Trinidad's water compare to other cities?
Trinidad ranks #641 out of 694 cities in California (better than 8% of state cities) and #14282 out of 15744 cities nationally (9th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.