Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03

Federal compliance data for Carlsbad, CA: no violations across 2 monitored systems.

Water Quality Map: Carlsbad, CA

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Water Quality by ZIP Code in Carlsbad

Water quality varies across Carlsbad's 6 ZIP codes. Check your specific ZIP for detailed contaminant data.

ZIP Code	Grade	Score	Violations	Health
92008	A	90	0	0	View report →
92009	A	90	0	0	View report →
92010	A	95	0	0	View report →
92011	A	95	0	0	View report →
92013	A	99	0	0	View report →
92018	A	99	0	0	View report →

Water Quality Overview

Carlsbad, California receives a water quality grade of A with an overall score of 95 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).

No EPA violations have been recorded for the 2 water systems serving Carlsbad. 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 A Means

A grade of A indicates excellent compliance with EPA drinking water standards. Carlsbad's water systems have maintained strong performance in both contaminant monitoring and regulatory compliance.

Lead Levels

The average 90th percentile lead level across Carlsbad water systems is 0.0014 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.

With 45% of homes built before 1986, Carlsbad 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.

Water Systems Serving Carlsbad

Carlsbad is served by 2 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 95,158 people across 6 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 Carlsbad

1. Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores

2. Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants

3. 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

4. Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics

5. Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts

Carlsbad vs. Nearby California Cities

How Carlsbad's water quality compares to similar cities in California:

Recommended Water Filters for Carlsbad

Based on contaminants detected in Carlsbad's water supply, these filter types are recommended:

Granular Activated Carbon (GAC, whole-house or under-sink)

• Removes: Total Chlorine Residual
• Effectiveness: 95-99%
• Cost range: $100–$600
• Certification: NSF/ANSI 42
• Recommended products:
  • Aquasana AQ-5200
  • Waterdrop Chubby Pitcher
  • Berkey Travel

Water Quality by ZIP Code in Carlsbad

Water quality varies across Carlsbad's ZIP codes. The table below shows the worst-scoring and best-scoring areas:

Common Questions About Carlsbad Water

These are the most common questions residents search for about water quality in Carlsbad, California:

Is Carlsbad water hard or soft? Water hardness varies by source. Carlsbad's 2 water systems use multiple sources. Check your ZIP code report for specific hardness data.

Can I drink Carlsbad tap water? Carlsbad's water receives a grade of A (95/100). No health-based violations have been recorded, but home testing is always recommended.

What is the best water filter for Carlsbad? Based on detected contaminants, a granular activated carbon (gac, whole-house or under-sink) filter is most recommended. See our Water Filter Matcher for personalized recommendations.

Carlsbad vs. California Average

Understanding how Carlsbad 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 Carlsbad.

ZIP Codes in Carlsbad

Carlsbad spans 6 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.

Your Water is Safe — Here's How to Keep It That Way

Grade A is excellent news. Here's what proactive homeowners do to maintain water quality:

Annual Water Testing

EPA recommends annual testing even with clean water. Home test kits: $20-$50. Catches changes before they become problems.

Maintenance Filtration

A basic carbon filter removes chlorine taste and catches emerging contaminants like PFAS that aren't yet fully regulated.

Plumbing Check

Even safe city water picks up lead from home pipes. If your home was built before 1986, a one-time pipe inspection is recommended.