01The verdict: is Santa Rosa Rancheria water safe?
Santa Rosa Rancheria's drinking water has significant quality concerns based on EPA testing data. With a grade of D (48/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 1,000 residents using groundwater (wells).
17 unresolved violations on record
EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓Lead is well under the limit
90th-percentile lead is 3.4 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓33 violations in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓Santa Rosa Rancheria's drinking water received a grade of D (48 out of 100), indicating poor water quality. The city's 1 water system serves approximately 1,000 residents using purchased ground water.
Lead levels were measured at 3.4 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 117 violations on record, including 25 health-based violations. 17 remain unresolved.
Santa Rosa Rancheria ranks #621 out of 690 cities in California for water quality, placing it among the lowest-rated in the state. Santa Rosa Rancheria purchases its water from a regional wholesaler, meaning quality depends on both the supplier's treatment and the local distribution system's condition. As a small community water system, Santa Rosa Rancheria may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 33 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
02What's in Santa Rosa Rancheria's water
Every contaminant flagged in Santa Rosa Rancheria, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
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. | 3.4 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in California
Cities ranked by compounds detected Cu Copper in California
Cities ranked by 90th-percentile copper
03Santa Rosa Rancheria's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 117 violations on record, including 25 health-based violations. 17 remain unresolved.
4 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▼ Down 5.2 ppb since 1997. Latest reading: 3.4 ppb (2025) — 23% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Santa Rosa Rancheria's water comes from
Santa Rosa Rancheria purchases its water supply from a regional wholesale provider rather than treating raw water directly.
Purchased Groundwater
Water is bought from a regional wholesaler; quality starts at the supplier's intake and treatment.
Wholesale supplier
Primary treatment happens at the wholesaler; the local utility maintains disinfectant residual in its pipes.
1 system
1 water system, operated under native american ownership.
1,000 people
Residents served across Santa Rosa Rancheria's service area.
Water quality depends on both the wholesaler's treatment standards and the condition of Santa Rosa Rancheria's local distribution pipes and storage facilities. Purchased water systems are common in suburban areas and smaller communities that lack the infrastructure for independent treatment. The system is operated by native american ownership and serves approximately 1,000 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| Santa Rosa Rancheria | 090600148 | 1,000 | Purchased Groundwater |
Water bodies near Santa Rosa Rancheria
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Santa Rosa Rancheria's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Flood & storm history
9 federal disaster declarations on record for Kings County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Santa Rosa Rancheria compares
Scores for nearby California cities on one line, with the average marked.
dashed line = California average (57/100)
Santa Rosa Rancheria scores 48/100 — below the California average of 57/100. It outscores 5 of 10 nearby cities. Full California rankings →
42.8 / 100FSan Jose, CA
28 / 100BOakland, CA
77.9 / 100FSan Diego, CA
39.7 / 100FSacramento, CA
31.2 / 100ABurlingame, CA
89.2 / 100
07What to do at home
Steps matched to what testing actually found in Santa Rosa Rancheria's water — not generic advice.
A basic carbon filter still helps
Santa Rosa Rancheria's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Santa Rosa Rancheria alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Santa Rosa Rancheria, CA tap water safe to drink?
Santa Rosa Rancheria's water quality earned a grade of D (48/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #621 out of 690 cities tested in California.
What contaminants are in Santa Rosa Rancheria's water?
Lead was measured at 3.4 ppb (90th percentile). 117 violations are on record.
How is Santa Rosa Rancheria'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 Santa Rosa Rancheria?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Santa Rosa Rancheria's water come from?
Santa Rosa Rancheria's water is sourced from Purchased ground water. The city has 1 water system serving approximately 1,000 residents.
What health violations has Santa Rosa Rancheria's water system had?
Santa Rosa Rancheria has 25 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 17 violations remain unresolved.
Is Santa Rosa Rancheria's groundwater at risk of contamination?
Santa Rosa Rancheria uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 117 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Santa Rosa Rancheria's water compare to other cities?
Santa Rosa Rancheria ranks #621 out of 690 cities in California (better than 10% of state cities) and #13280 out of 15382 cities nationally (14th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Santa Rosa Rancheria's small water system affect quality?
Santa Rosa Rancheria's system serves approximately 1,000 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 117 violations on record.