Is Portola, CA Tap Water Safe to Drink?
Graded C- — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
55.1/100
waterverge.com Portola, CA — Water Quality Report
Portola's drinking water received a grade of C- (55.1 out of 100), indicating poor water quality. The city's 6 water systems serve approximately 4,146 residents using purchased surface water.
Lead levels were measured at 0.0 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 118 violations on record, including 71 health-based violations. 4 remain unresolved.
What to know about Portola's water
Portola ranks #588 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.
The system has seen 17 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Portola, CA water safe to drink?
Portola's drinking water has significant quality concerns based on EPA testing data. With a grade of C- (55.1/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 6 water systems serve approximately 4,146 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Portola
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Portola's water quality assessment. Grade: C- (55.1/100).
Contaminants: Lead and Copper Rule.
1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS, Revised Total Coliform Rule.
Contaminants: Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4308). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Portola'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
Portola's water system has 118 total violations on record, including 71 health-based violations. 4 remain unresolved. 17 violations were issued in the last 5 years.
Flood & environmental risk
Plumas County has experienced 8 federally declared disasters since 1964. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Portola's water come from?
Portola's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 6 water systems serving approximately 4,146 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment.
What Portola residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Portola'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.
Portola'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
Drought conditions
D1 — moderate droughtPlumas County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Plumas County has experienced 8 federally declared disasters since 1964. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Portola'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. | 0.0 | 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. | 2.50 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 2.500 mg/L (1995)
EPA action level: 1.3 mg/L
See how Portola compares by contaminant
Explore where Portola ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Portola's water comes from
Portola'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 4,146 people through 6 water systems.
Water systems serving Portola
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CITY OF PORTOLA | CA3210003 | 2,100 | SWP |
| GRIZZLY LAKE CSD-DELLEKER | CA3200104 | 1,314 | GW |
| GREENHORN CREEK CSD | CA3200188 | 280 | GW |
| GRIZZLY LAKE CSD-CROCKER/WELCH | CA3200107 | 215 | GW |
| GOLD MOUNTAIN CSD | CA3205003 | 135 | GW |
| GRIZZLY RANCH CSD | CA3205006 | 102 | GW |
How Portola compares
Full California rankings →Portola's score of 55.1/100 is on par with the average of 57/100 among major California cities. It outscores 5 of 10 nearby cities.
Nearby cities
View California rankings →About Portola, CA
Learn more about your water
Guides and resources related to Portola's water quality findings.
Explore water quality across Plumas
Frequently asked questions
Is Portola, CA tap water safe to drink?
Portola's water quality earned a grade of C- (55.1/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #588 out of 694 cities tested in California.
What contaminants are in Portola's water?
Lead was measured at 0.0 ppb (90th percentile). 118 violations are on record.
How is Portola'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 Portola?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Portola's water come from?
Portola's water is sourced from Purchased surface water. The city has 6 water systems serving approximately 4,146 residents.
What health violations has Portola's water system had?
Portola has 71 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 4 violations remain unresolved.
How does Portola's water compare to other cities?
Portola ranks #588 out of 694 cities in California (better than 15% of state cities) and #12553 out of 15744 cities nationally (20th percentile). The grade of C- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.