Carlsbad, CA Water Safety: 95/100 (2026)
6 ZIP codes · 8 water systems · Updated 2026-06-03
How does Carlsbad tap water hold up under EPA scrutiny? Above average for CA — documented violations are uncommon and the safety grade reflects a clean overall record.
How Carlsbad Compares
Data: EPA SDWIS Last verified: 2026-06-03
Water Quality Map: Carlsbad, CA
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Score Distribution
How ZIP codes in Carlsbad score across all safety grades.
What You Should Know About Carlsbad Water
- Average lead level: 0.0014 mg/L.
- Homes built before 1986: 45% — older plumbing may contain lead solder.
- Estimated remediation: $1,200 per household.
- CDC health risk index: 10.18.
Who Supplies Your Water in Carlsbad
In Carlsbad, CA, residential water supply is distributed across multiple utilities rather than concentrated in one. The 3 leading providers out of 8 tracked systems each control their own infrastructure, file separate EPA compliance reports, and set independent rate schedules.
Overview
We track water quality and home safety data for 6 ZIP codes in Carlsbad, California (population ~114,500), covering 8 community water systems serving approximately 639,434 people region-wide.
No EPA violations recorded across any ZIP codes in Carlsbad — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Carlsbad: A (95/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Carlsbad water systems draw from: Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0014 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 3 (Low Risk)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 0 ZIP codes
- Zone 3 (Low): 6 ZIP codes
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 92008 | A | Carlsbad Mwd | 95,158 |
| 92009 | A | Carlsbad Mwd | 95,158 |
| 92010 | A | Carlsbad Mwd | 95,158 |
| 92011 | A | Carlsbad Mwd | 95,158 |
| 92013 | A | Carlsbad Mwd | 95,158 |
| 92018 | A | Carlsbad Mwd | 95,158 |
All ZIP Codes in Carlsbad
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
Updated daily.
Health Outcomes in Carlsbad
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Housing & Infrastructure in Carlsbad
With 45% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Two regulatory milestones define plumbing-era risk in residential housing: 1970, when lead pipes were still commonly installed for service lines, and 1986, when lead solder was banned from new copper plumbing. A median build year of 1987 places Carlsbad in the middle zone between those thresholds — with a meaningful share of housing predating both cutoffs. The distribution shown above breaks out those eras explicitly, clarifying where concentrated risk sits across the residential inventory.
Most homes in Carlsbad were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Carlsbad Homeowners
Remediation costs in Carlsbad are small relative to typical property values — the cost-to-value ratio here is favorable.
Remediation costs in Carlsbad are relatively low compared to home values. The $800–$1,800 estimated range is a small fraction of median property value. Home values are 61% above the California average.
Lead Exposure Risk for Children in Carlsbad
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Pulling a tap sample fills the gap that utility data cannot close, particularly here where 45% of housing dates from the pre-rule era and citywide monitoring sits at or above the regulatory mark in Carlsbad.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Carlsbad
FEMA data shows 67% of Carlsbad's ZIP codes mapped into designated flood zones, paired with an NFIP record of 57 claims. That footprint places local flood exposure in the range where it warrants attention without rising to high-severity planning territory.
Carlsbad has a moderate flood history with 57 FEMA claims averaging $3,896 per payout. 67% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$1,200</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
Deep Dive Reports
Detailed analysis for Carlsbad, CA