Larkspur, CA: 2 Violations — 85/100 (2026)
2 ZIP codes · 2 water systems · Updated 2026-06-03
In current tracking cycles, Larkspur records above-average water quality outcomes for CA; compliance history over recent years shows few departures from federal standards and no systemic failures across its water systems.
How Larkspur Compares
Data: EPA SDWIS Last verified: 2026-06-03
Larkspur Water: The Quick Version
- Your city's water systems recorded 2 violations in the past 5 years.
- Average lead level: 0.0076 mg/L.
- Estimated remediation: $1,000 per household.
- CDC health risk index: 10.78.
Water Systems Serving Larkspur
2 water systems are tracked federally in Larkspur, CA. The top 2 providers collectively serve most residential addresses, but because they operate independently, infrastructure maintenance standards and compliance histories differ from one service zone to another.
Overview
We track water quality and home safety data for 2 ZIP codes in Larkspur, California (population ~7,372), covering 2 community water systems serving approximately 187,211 people region-wide.
2 of 2 ZIP codes (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Larkspur: A (85/100)
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
Larkspur water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0076 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): 2 ZIP codes
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting | 3 | 2 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 94939 | B | 1 | 0 | Marin Municipal Water District |
| 94977 | A | 1 | 0 | Cascade Estates |
All ZIP Codes in Larkspur
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.
CDC Health Data for Larkspur
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
Key Contaminants Detected in Larkspur
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Larkspur: Remediation Cost in Perspective
In Larkspur, property values comfortably outpace what documented remediation typically costs — the equity share is proportionally low.
Remediation costs in Larkspur are relatively low compared to home values. The $400–$1,700 estimated range is a small fraction of median property value. Home values are 171% above the California average.
Protecting Children from Lead in Larkspur
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.
Lead risk in Larkspur appears low overall, but individual homes may differ. Testing is the only way to confirm your water's lead content.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Larkspur
NFIP records stretching across multiple decades show Larkspur accumulating 101 claims and carrying 50% of its ZIP codes inside FEMA flood zones — evidence of meaningful exposure that extends beyond isolated incidents. The mechanisms linking flooding to water quality haven't changed: treatment facilities can be overwhelmed, wells can be infiltrated, and distribution systems can experience backflow. For a community at this exposure level, those mechanisms shift from hypothetical to periodically relevant.
Larkspur has a moderate flood history with 101 FEMA claims averaging $12,231 per payout. 50% 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>$1,000</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 Larkspur, CA