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EPA SDWIS City OverviewWater Testing & Safety Guide

San Diego, CA Water Quality Testing & Safety Report

EPA compliance records, water testing guidelines, and hardness metrics for all 81 ZIP codes in San Diego, California

Quick EPA Verified Summary

Is Tap Water Safe to Drink in San Diego, CA?

Tap water in San Diego, CA receives an EPA Safety Grade of C (60/100) due to 324 health-based violation(s) and elevated lead risk. While treated by local utilities, residents are advised to test tap water and use an NSF/ANSI 53 certified filter for drinking and cooking.

Average Score

60/100

Health Violations

324

Water Hardness

Moderately Hard

105 mg/L (6.1 GPG)

High Lead Risk

28

of 81 ZIP codes

C

About Tap Water in San Diego, CA

Drinking water in San Diego, CA receives an average water quality grade of C (score: 60/100) across its 81 ZIP codes. Safe Drinking Water Act compliance monitoring is managed by local utilities including City of San Diego,.

⚠ Lead Risk Alert: Some ZIP codes in San Diego are rated High or Very High for lead exposure risk based on EPA data. Search your specific ZIP code for a detailed lead level report.

Water Quality Testing in San Diego, CA

Tap Water & Well Water Testing Recommendations

Testing your drinking water in San Diego confirms whether contaminants like lead, nitrates, bacteria, and PFAS are entering your home. While municipal utilities test water before distribution, private plumbing and private well systems require homeowner testing.

Tap Water Testing Checklist

  • 1.Identify your plumbing age: Homes built before 1986 in San Diego may have lead solder or lead service lines.
  • 2.Request your utility's latest Consumer Confidence Report (CCR) for annual municipal baseline data.
  • 3.Use an EPA-certified laboratory or state-certified test kit for precision lead and PFAS detection (standard DIY strips cannot reliably measure trace heavy metals).
  • 4.Collect a "first draw" sample: Test water that has sat motionless in pipes for at least 6 hours to check for plumbing corrosion.

Private Well Water Testing Checklist

  • •Private wells in CA are not monitored by the EPA or California State Water Resources Control Board — testing is 100% the homeowner's responsibility.
  • •Annual Test: Screen for Total Coliform Bacteria, E. coli, Nitrates/Nitrites, and pH every spring.
  • •Comprehensive Test (Every 3-5 Years): Test for heavy metals (Lead, Arsenic, Uranium), Volatile Organic Compounds (VOCs), and Hardness.
  • •Post-Disruption Testing: Immediately test well water following heavy floods, local construction, agricultural runoff, or sudden taste/odor changes.

Critical Water Testing Parameters for San Diego Residents

ParameterHealth ReasonEPA Limit / Standard
Lead (Pb)Plumbing corrosion; dangerous neurotoxin for children15 ppb (Action Level) / 0 ppb Goal
Total Coliform & E. ColiBacterial contamination from sewage or surface runoff0 mg/L (Zero Tolerance)
Nitrates / NitritesFertilizer and septic tank seepage; causes blue baby syndrome10 mg/L (MCL)
Water Hardness (Ca & Mg)Affects appliance lifespan, scale buildup, and skin hydrationModerate (~100 mg/L)
PFAS ("Forever Chemicals")Industrial non-stick chemicals linked to metabolic and immune issues4.0 ppt (EPA 2024 Rule)
State Regulatory Oversight: Environmental standards and certified water lab registries in CA are maintained by the California State Water Resources Control Board.

Health-Based Contaminant Violations in San Diego

EPA records indicate that the following contaminants have exceeded Safe Drinking Water Act Maximum Contaminant Levels (MCLs) in San Diego water systems over the past 5 years.

Consumer Confidence Report RuleStage 2 DBP Rule

Note: The presence of a past violation does not necessarily mean current water is unsafe. Utilities are required to take corrective action. Review your Consumer Confidence Report for the latest status.

Water Quality by ZIP Code — San Diego, CA

Showing 81 of 81 monitored ZIP codes in San Diego

C
92104

San Diego, CA

Score: 65/1004 violations
C
92111

San Diego, CA

Score: 65/1004 violations
C
92119

San Diego, CA

Score: 65/1004 violations
C
92122

San Diego, CA

Score: 65/1004 violations
C
92123

San Diego, CA

Score: 65/1004 violations
C
92124

San Diego, CA

Score: 65/1004 violations
C
92126

San Diego, CA

Score: 65/1004 violations
C
92127

San Diego, CA

Score: 65/1004 violations
C
92128

San Diego, CA

Score: 65/1004 violations
C
92129

San Diego, CA

Score: 65/1004 violations
C
92130

San Diego, CA

Score: 65/1004 violations
C
92131

San Diego, CA

Score: 65/1004 violations
C
92139

San Diego, CA

Score: 65/1004 violations
C
92102

San Diego, CA

Score: 60/1004 violations
C
92103

San Diego, CA

Score: 60/1004 violations
C
92105

San Diego, CA

Score: 60/1004 violations
C
92106

San Diego, CA

Score: 60/1004 violations
C
92107

San Diego, CA

Score: 60/1004 violations
C
92110

San Diego, CA

Score: 60/1004 violations
C
92112

San Diego, CA

Score: 60/1004 violations
C
92114

San Diego, CA

Score: 60/1004 violations
C
92115

San Diego, CA

Score: 60/1004 violations
C
92116

San Diego, CA

Score: 60/1004 violations
C
92117

San Diego, CA

Score: 60/1004 violations

All San Diego, CA ZIP Code Reports (81 Total)

921049211192119921229212392124921269212792128921299213092131921399210292103921059210692107921109211292114921159211692117921329213392134921359213692137921389214092142921459214792149921509215292153921549215592158921599216092161921629216392164921659216692167921689216992170921719217292174921759217692177921799218292184921869218792190921919219292193921949219592196921979219892199921089210992113921209212192101

Nearby Cities Water Quality & Testing in California

Compare tap water safety, EPA test scores, and water hardness across neighboring cities in California:

Agoura Hills, CA2 ZIP codes
Grade B
Adelanto, CA1 ZIP code
Grade B
Acampo, CA1 ZIP code
Grade B
Acton, CA1 ZIP code
Grade C
Alameda, CA2 ZIP codes
Grade C
Alamo, CA1 ZIP code
Grade C
Albany, CA1 ZIP code
Grade C
Albion, CA1 ZIP code
Grade A

Frequently Asked Questions — San Diego Water Quality & Testing

Is tap water safe to drink in San Diego, CA?+
Tap water in San Diego has a grade of C, indicating compliance concerns in recent years. Families with young children or pregnant women should consider using a certified NSF/ANSI 53 water filter for drinking and cooking.
How do I test water quality in San Diego, CA?+
To test water quality in San Diego, you can order an EPA-compliant drinking water test kit or submit samples to a state-certified environmental testing laboratory in CA. Testing is especially recommended for homes built before 1986 (to check for lead in plumbing) and for properties with private well systems.
Should I test private well water in San Diego?+
Yes. Unlike municipal tap water, private wells in San Diego, CA are not monitored or regulated by the EPA or local utilities. Private well owners are responsible for testing their water annually for coliform bacteria and nitrates, and every 3 to 5 years for heavy metals (lead, arsenic) and volatile organic compounds.
How hard is the tap water in San Diego?+
Tap water in San Diego is classified as Moderately Hard with an estimated average hardness of 105 mg/L (6.1 GPG). A water softener is generally optional.
What is the water quality score for San Diego?+
The average water quality score across 81 ZIP codes in San Diego, CA is 60/100. Scores are derived from EPA violation history, lead levels, enforcement actions, and infrastructure risk indicators. Individual ZIP codes may vary — search your specific ZIP above for a personalized report.
Does San Diego have lead in its tap water?+
28 out of 81 ZIP codes in San Diego are rated High or Very High for lead exposure risk. Older homes built before 1986 may have lead service lines or plumbing fixtures. Residents should run their tap for 30 seconds before use and consider a certified NSF/ANSI 53 lead filter.
Where does San Diego's tap water come from?+
Tap water in San Diego, CA primarily comes from surface water. Surface water systems treat water from rivers, lakes, or reservoirs using filtration, sedimentation, and disinfection before it reaches your tap.

Looking for water quality reports in other cities in California?

View All Cities & ZIPs in California