Stockton Drinking Water Quality
What's Really in Your Tap Water?
Stockton tap water has some quality concerns you should be aware of. At just 114 ppm (6.7 gpg), the water is pleasantly soft. Lead levels test well below the EPA action level. There have been 9 violations recorded over the past 3 years.
Some Concerns
Monitor recommended
6.7 GPG hardness
Lead
Below EPA action level
EPA action level: 15 ppb
Hardness
Moderate water
US Average: 100 ppm
Is Stockton Tap Water Safe to Drink?
Stockton tap water has some quality concerns but remains within acceptable limits.
EPA Violations — 8 health-based EPA violations in the past 3 years across 2 water systems. Plus 1 monitoring/reporting violation.
Health-based violations mean the water exceeded a federal maximum contaminant level. This is more serious than administrative violations.
→ Consider testing your water at home and using a certified water filter until violations are resolved.
Lead — Lead (0.2 ppb) is at 1% of the EPA action level of 15 ppb.
The data below shows test results from 2 water utilities serving 197K people in the Stockton area.
Based on publicly available data from EPA Water Quality Portal (Various). Water quality can vary by location, building plumbing, and over time. This assessment reflects compliance with federal EPA standards and is not medical advice.
Do I Need a Water Filter?
Based on recent water quality data, a water filter may be beneficial in Stockton. A basic carbon filter can improve taste and reduce common contaminants.
How Hard is Stockton Water?
114 ppm
6.7 grains per gallon
Impact on Your Home
Shower
Minor dryness possible
Kitchen
Some water spots
Laundry
May need more detergent
Appliances
Minimal scale
Regional Comparison
Values in ppm (mg/L as CaCO₃)
Based on 90 water samples from San Joaquin County
Your pipes tell a different story
The data above shows what leaves the treatment plant—not what comes out of your faucet. Old pipes, lead solder, and building plumbing can add contaminants the city never tests for. Know exactly what's in your Stockton tap water.
Home test kits detect lead, bacteria, pesticides, and 100+ other contaminants. Results in 5-10 business days from certified labs.
Lead & Contaminants
Understanding lead levels and water quality violations in Stockton
Lead Test Results
90th Percentile Lead Level
0.2 ppb
Stockton lead levels are well below the EPA action level.
Regular testing is still recommended, as lead can enter water through household plumbing.
Last sampled: 2026-12-31
About Lead in Drinking Water
What is Lead in Water?
According to the EPA, lead is a toxic metal that can dissolve into drinking water from older pipes, solder, and fixtures. It's invisible, tasteless, and odorless, making testing the only way to detect it. The EPA has set an action level of 15 ppb and states there is no safe level of lead exposure.
Potential Health Effects
According to the CDC: developmental delays, learning difficulties, lower IQ, behavioral issues
According to the EPA: high blood pressure, kidney damage, reproductive issues
How to Reduce Exposure
- •Run water for 30 seconds to 2 minutes before drinking, especially in the morning
- •Use cold water for cooking and drinking (hot water dissolves more lead)
- •Install a NSF-certified filter designed to remove lead
- •Test your water, especially if your home was built before 1986
EPA Compliance History
Action Recommended
Active health-based violations detectedConsider using a certified water filter until violations are resolved. Contact your utility for updates on corrective actions.
3-Year Violation Summary
9
Total Violations
8
Health-Related
1
Administrative
Health-Related Violations
Contaminant exceeded EPA maximum contaminant levels. The EPA recommends considering certified filtration.
Administrative Violations
Missed testing deadlines or reporting. Does not indicate water quality issues.
Who Provides Stockton's Water?
Utility Name
CITY OF STOCKTON
EPA System ID (PWSID)
CA3910012
Primary Water Source
Surface Water
Population Served
197K
Frequently Asked Questions
Common questions about Stockton tap water quality
Nearby Cities in California
Los Angeles
Hard water
East Bay
Very Hard water
San Diego
Very Hard water
San Jose
Very Hard water
California
Hard water
Eastern Municipal Wd
Very Hard water
This data is for informational purposes only. Water quality can vary by neighborhood and building. For official reports, contact your local water utility or the EPA. Learn about our methodology
Data source: EPA Water Quality Portal (environmental samples, not verified tap water)