Is Whitethorn, CA Tap Water Safe to Drink?
Graded B+, with 2 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
84.7/100
waterverge.com Whitethorn, CA — Water Quality Report
Whitethorn's drinking water received a grade of B+ (84.7 out of 100), indicating good water quality. The city's 2 water systems serve approximately 919 residents using surface water.
Lead levels were measured at 3.2 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 69 violations on record, including 38 health-based violations. 2 remain unresolved.
What to know about Whitethorn's water
Whitethorn ranks #277 out of 694 cities in California for water quality, placing it mid-range 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, Whitethorn may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Whitethorn, CA water safe to drink?
Whitethorn's tap water meets most EPA standards but has areas that warrant attention. With a grade of B+ (84.7/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 2 water systems serve approximately 919 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Whitethorn
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Whitethorn's water quality assessment. Grade: B+ (84.7/100).
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.
Contaminants: Revised Total Coliform Rule.
Contaminants: Revised Total Coliform Rule.
1 health-based. Contaminants: Interim Enhanced Surface Water Treatment Rule.
Key contaminant findings
Based on the most recent EPA sampling data for Whitethorn's water supply.
Well within EPA limits.
Violation history
Whitethorn's water system has 69 total violations on record, including 38 health-based violations. 2 remain unresolved. 1 violation was 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 Mattole R Nr Ettersburg.
Where does Whitethorn's water come from?
Whitethorn's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 2 water systems serving approximately 919 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Mattole R Nr Ettersburg (river).
What Whitethorn residents can do
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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Whitethorn'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.
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. | 3.2 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Whitethorn compares by contaminant
Explore where Whitethorn ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Whitethorn's water comes from
Whitethorn'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 919 people through 2 water systems.
Water bodies near Whitethorn
Whitethorn is located near 1 notable water body. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Whitethorn
| System Name | PWSID | Population | Source |
|---|---|---|---|
| RESORT IMPROVEMENT DISTRICT #1 | CA1210022 | 803 | SW |
| REDCREST WATER WORKS | CA1200544 | 116 | SW |
How Whitethorn compares
Full California rankings →Whitethorn's score of 84.7/100 is above the average of 57/100 among major California cities. It outscores 8 of 10 nearby cities.
Nearby cities
View California rankings →Learn more about your water
Guides and resources related to Whitethorn's water quality findings.
Explore water quality across Humboldt
Frequently asked questions
Is Whitethorn, CA tap water safe to drink?
Whitethorn's water quality earned a grade of B+ (84.7/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #277 out of 694 cities tested in California.
What contaminants are in Whitethorn's water?
Lead was measured at 3.2 ppb (90th percentile). 69 violations are on record.
How is Whitethorn'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 Whitethorn?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Whitethorn's water come from?
Whitethorn's water is sourced from Surface water. The city has 2 water systems serving approximately 919 residents.
What health violations has Whitethorn's water system had?
Whitethorn has 38 health-based violations on record. The most recent violation was recorded in September 2022. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 2 violations remain unresolved.
How does Whitethorn's water compare to other cities?
Whitethorn ranks #277 out of 694 cities in California (better than 60% of state cities) and #5744 out of 15744 cities nationally (64th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.