A84/100
Sonora Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 35,616 residents · California
What's In Sonora's Tap Water?
31
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 1996.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
TUD - SONORA/JAMESTOWN WATER SYSTEM
Population Served
11,054
Water Source
Surface Water
System ID
CA5510001
TUD - PONDEROSA
Population Served
1,767
Water Source
Surface Water
System ID
CA5510002
TUD - TUOLUMNE WATER SYSTEM
Population Served
1,761
Water Source
Surface Water
System ID
CA5510003
TUD - UPPER BASIN WATER SYSTEM
Population Served
13,280
Water Source
Surface Water
System ID
CA5510012
TUD - COLUMBIA WATER SYSTEM
Population Served
5,463
Water Source
Surface Water
System ID
CA5510013
SONORA MEADOWS MUTUAL WTR CO
Population Served
1,123
Water Source
Purchased Surface Water
System ID
CA5510023
PHOENIX LAKE ESTATES CC MWC
Population Served
1,168
Water Source
Groundwater
System ID
CA5510026
Frequently Asked Questions About Sonora Water
Is Sonora tap water safe to drink?
Sonora, California tap water receives a grade of A (84/100), which is considered excellent. Out of 69 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 2 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Sonora's water?
Of the 69 contaminants tested in Sonora's water supply, the most notable include Lead (90th percentile), chlorate. No contaminants exceed EPA legal limits. 2 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Sonora have any water quality violations?
Yes, Sonora has 49 EPA violation(s) on record, with the most recent in 2025. Violation types include MON, RPT, TT. 12 of these are health-based violations, which are the most serious category.
Do I need a water filter in Sonora?
Sonora water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 2 contaminant(s) exceed these stricter goals.
Where does Sonora's tap water come from?
Sonora's drinking water is sourced from surface water and supplied by TUD - SONORA/JAMESTOWN WATER SYSTEM and 6 other water system(s). The system serves approximately 35,616 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Sonora's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Sonora's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Sonora's water compare to other cities in California?
Sonora's water quality score of 84/100 earns a grade of A, which is considered excellent. This places Sonora among the better-performing water systems in California. Visit our California state page to see how all cities in the state compare.
What should I do if I'm concerned about Sonora's water quality?
If you have concerns about Sonora's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (TUD - SONORA/JAMESTOWN WATER SYSTEM) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.