Water Quality in Gardena, CA: No Violations — Grade C
Grade C · Score 60/100 · 3 water systems · Updated 2026-05-03
Gardena's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Across all 3 water systems serving Gardena, CA, federal monitoring data documents zero EPA violations — no MCL exceedances, no monitoring lapses, no enforcement actions anywhere in the compliance history.
Water Quality by ZIP Code in Gardena
Water quality varies across Gardena's 3 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 90248 | D | 53 | 0 | 0 | View report → |
| 90247 | C | 63 | 0 | 0 | View report → |
| 90249 | C | 63 | 0 | 0 | View report → |
Water Quality Overview
Gardena, California receives a water quality grade of C with an overall score of 60 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
No EPA violations have been recorded for the 3 water systems serving Gardena. This is a positive indicator, though it does not guarantee the absence of all contaminants — some substances (like PFAS) are not yet fully regulated.
What Grade C Means
A grade of C indicates moderate compliance issues. Gardena's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.
Lead Levels
Lead testing data for Gardena is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
With 81% of homes built before 1986, Gardena has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Gardena is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Gardena
Gardena is served by 3 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 458,800 people across 3 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
How to Check Your Water in Gardena
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Gardena vs. Nearby California Cities
How Gardena's water quality compares to similar cities in California:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Gardena | C | 0 | 3 | 458,800 |
| Long Beach | A | 513 | 2 | 466,792 |
| Irvine | A | 84 | 5 | 447,086 |
| East Irvine | C | 0 | 1 | 444,800 |
Water Quality by ZIP Code in Gardena
Water quality varies across Gardena's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
Common Questions About Gardena Water
These are the most common questions residents search for about water quality in Gardena, California:
Is Gardena water hard or soft? Water hardness varies by source. Gardena's 3 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Gardena tap water? Gardena's water receives a grade of C (60/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Gardena? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Gardena vs. California Average
Understanding how Gardena compares to the broader California average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Gardena.
ZIP Codes in Gardena
Gardena spans 3 ZIP codes. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.