Is Downieville, CA Tap Water Safe to Drink?
Graded B+, with 3 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
84.5/100
waterverge.com Downieville, CA — Water Quality Report
Downieville's drinking water received a grade of B+ (84.5 out of 100), indicating good water quality. The city's 2 water systems serve approximately 1,509 residents using 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 23 violations on record, including 3 health-based violations. 3 remain unresolved.
What to know about Downieville's water
Downieville ranks #282 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, Downieville may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Downieville, CA water safe to drink?
Downieville's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (84.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 1,509 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Downieville
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Downieville's water quality assessment. Grade: B+ (84.5/100).
Contaminants: Revised Total Coliform Rule.
1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS.
1 health-based. 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 Downieville's water supply.
Well within EPA limits.
Violation history
Downieville's water system has 23 total violations on record, including 3 health-based violations. 3 remain unresolved. 4 violations were issued in the last 5 years.
Flood & environmental risk
Sierra County has experienced 7 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. Local water sources include N Yuba R Bl Goodyears Bar.
Where does Downieville's water come from?
Downieville's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 2 water systems serving approximately 1,509 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include N Yuba R Bl Goodyears Bar (river).
What Downieville residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Downieville'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.
Downieville'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 droughtSierra 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
Sierra County has experienced 7 federally declared disasters since 1964. 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. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Downieville compares by contaminant
Explore where Downieville ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Downieville's water comes from
Downieville'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 1,509 people through 2 water systems.
Water bodies near Downieville
Downieville 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 Downieville
| System Name | PWSID | Population | Source |
|---|---|---|---|
| DOWNIEVILLE PUBLIC U.D. | CA4610002 | 783 | SW |
| SIERRA CSA #5, SIERRA BROOKS | CA4600009 | 726 | GW |
How Downieville compares
Full California rankings →Downieville's score of 84.5/100 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 Downieville's water quality findings.
Explore water quality across Sierra
Frequently asked questions
Is Downieville, CA tap water safe to drink?
Downieville's water quality earned a grade of B+ (84.5/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #282 out of 694 cities tested in California.
What contaminants are in Downieville's water?
Lead was measured at 0.0 ppb (90th percentile). 23 violations are on record.
How is Downieville'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 Downieville?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Downieville's water come from?
Downieville's water is sourced from Surface water. The city has 2 water systems serving approximately 1,509 residents.
What health violations has Downieville's water system had?
Downieville has 3 health-based violations on record. The most recent violation was recorded in November 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.
How does Downieville's water compare to other cities?
Downieville ranks #282 out of 694 cities in California (better than 59% of state cities) and #5871 out of 15744 cities nationally (63th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.