Rancho Santa Fe, CA Water Safety: 93/100 (2026)
2 ZIP codes · 3 water systems · Updated 2026-06-03
In current CA EPA data, Rancho Santa Fe's tap water sits in the high-safety tier.
How Rancho Santa Fe Compares
Data: EPA SDWIS Last verified: 2026-06-03
Rancho Santa Fe Water: The Quick Version
- Average lead level: 0.0017 mg/L.
- Homes built before 1986: 49% — older plumbing may contain lead solder.
- Estimated remediation: $1,700 per household.
- CDC health risk index: 10.18.
Water Systems Serving Rancho Santa Fe
Structurally, Rancho Santa Fe, CA's water supply is divided. Federal data identifies 3 water systems in the area, with 3 providers serving the bulk of residential connections. These utilities operate independently, meaning rate-setting authority and EPA compliance accountability are distributed rather than centralized.
Overview
We track water quality and home safety data for 2 ZIP codes in Rancho Santa Fe, California (population ~9,460), covering 3 community water systems serving approximately 1,493,415 people region-wide.
No EPA violations recorded across any ZIP codes in Rancho Santa Fe — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Rancho Santa Fe: A (93/100)
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
Rancho Santa Fe water systems draw from: Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0017 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
Areas with No Violations
All ZIP Codes in Rancho Santa Fe
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 Rancho Santa Fe
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
How Old Is Rancho Santa Fe's Housing Stock?
With 49% 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
Plumbing risk in residential housing tracks directly to construction era: pre-1986 homes may have lead-soldered copper joints; pre-1970 homes may have lead pipes outright. Rancho Santa Fe's median build year of 1983 places the city in a moderate risk zone where neither era dominates the housing inventory. Understanding which side of the 1986 threshold a specific property falls on — and whether it predates 1970 — is the most actionable starting point for a homeowner trying to assess their own tap water exposure.
Most homes in Rancho Santa Fe 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.
Rancho Santa Fe: Remediation Cost in Perspective
In Rancho Santa Fe, the equity impact of remediation is proportionally small — not the kind of financial commitment that rises to the level of a genuine planning constraint, but a minor share of what most properties here are worth.
Remediation costs in Rancho Santa Fe are relatively low compared to home values. The $1,100–$2,600 estimated range is a small fraction of median property value. Home values are 171% above the California average.
Protecting Children from Lead in Rancho Santa Fe
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.
Even where utility-side monitoring meets Lead and Copper Rule requirements, the 49% pre-rule share in Rancho Santa Fe keeps interior-plumbing variation as a household-level question that aggregate data cannot resolve.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Rancho Santa Fe
Within the NFIP's national dataset, Rancho Santa Fe falls in moderate-exposure territory — 36 documented incidents spanning multiple decades, with 100% of local ZIP codes sitting inside FEMA flood boundaries. That combination warrants inclusion in any thorough local water quality review.
Rancho Santa Fe has a moderate flood history with 36 FEMA claims averaging $3,305 per payout. 100% 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>$1,700</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 Rancho Santa Fe, CA