CITY REPORT CA

Rancho Santa Margarita, CA Home Safety: Home Safety 92/100

1 ZIP code · 2 water systems · Updated

ZipCheckup grade for Rancho Santa Margarita: A.

Checked records flag no major concern; missing data is unknown.

In the dataset behind this page, Rancho Santa Margarita, CA receives one of the two highest grades; read the compliance history system by system for details.

How Rancho Santa Margarita Compares

Rancho Santa Margarita92/100
California avg76/100
National avg73/100

Data: EPA SDWIS

1
ZIP Codes
2
Water Systems
0
ZIPs Linked to Systems with Violations
A · 92
Avg Safety Score
Zone 3
County Radon Potential (Low)
$857K
Median Home Value

Key Facts for Rancho Santa Margarita Residents

  • Average of reported 90th-percentile lead results: 0.0039 mg/L.
  • Homes built before 1986: 23% - older plumbing may contain lead solder.
  • Health risk index (ZipCheckup composite of CDC data): 10.23.

Rancho Santa Margarita's Water Providers

Federal records list 2 water systems tied to Rancho Santa Margarita, CA. Of those, 2 are the primary providers, meaning service conditions, rate structures, and compliance histories can differ depending on where a property sits.

Overview

We track home safety data for 1 ZIP code in Rancho Santa Margarita, California (population ~43,937), covering 2 community water systems serving approximately 181,948 people region-wide. The EPA snapshots used for this build directly map water systems to 1 of 1 ZIP codes.

The available EPA record reports 0 violations for 1 ZIP code with a reported violation count.

Home Safety Score

Average Home Safety Score for Rancho Santa Margarita: A (92/100)

Model 4.0.0 uses four measured components across three equally weighted domains. If a required domain is unavailable, no score is published:

Factor What It Measures
Water Quality EPA violations and compliance history
PFAS MCL Screen UCMR 5 testing against the covered federal MCLs
Radon Risk EPA radon zone classification
Annual AQI EPA AirData county-year median with at least 90 observed days

Water Sources

Rancho Santa Margarita water systems draw from: Surface water.

Lead & Copper

  • Average of reported 90th-percentile lead results: 0.0039 mg/L (EPA action level: 0.015 mg/L)
  • 0 of 1 ZIP code with known status exceed the EPA lead action level

Radon Risk

1 of 1 ZIP records with known zones is in EPA Radon Zone 3.

The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.

Areas with No Violations

ZIP Code Safety Score System Population
92688 A Santa Margarita Water District 168,289

All ZIP Codes in Rancho Santa Margarita

Data Sources

Reporting periods vary by source. Missing data is shown as unavailable, not as zero.

Rancho Santa Margarita Community Health Snapshot

9%
Asthma (US: 9.8%)
11.5%
Diabetes (US: 10.4%)
16%
Poor Mental Health (US: 14.8%)

Source: CDC PLACES (County-level estimates). County health indicators are shown for context only and are not linked to this area's water records.

Compared to National Average

Asthma 9% ↓
Diabetes 11.5% ↑
Mental Health 16% ↑

Vertical line = national average. ■ Above national · ■ Below national

Rancho Santa Margarita Infrastructure Age

1997
Median Build Year
23%
Built Before 1986
2%
Built Before 1970
Copper
Likely Pipe Material

Housing age data helps assess potential lead pipe and infrastructure risks. Newer housing stock generally means lower plumbing-related contamination risk.

Source: U.S. Census Bureau American Community Survey (ACS).

Housing Age Profile

Federal restrictions on lead pipe, solder and flux in new drinking water plumbing date from the 1986 Safe Drinking Water Act amendments; the median build year of 1997 for Rancho Santa Margarita is one reference point against that date.

1997
Median Year Built
23%
Pre-1986 (lead solder era; lead paint banned 1978)
2%
Pre-1970 (Lead Pipes Risk)
Pre-1970 (2%) 1970–1986 (21%) Post-1986 (77%)

Most homes in Rancho Santa Margarita were built after 1986; lead exposure at a tap still depends on its service line and plumbing. Older homes should still be tested.

Source: U.S. Census Bureau ACS B25034.

Rancho Santa Margarita: Lead Risk & Vulnerable Populations

23%
Homes Built Before 1986
0.0039
mg/L average of reported water-system 90th-percentile lead results (the 0.015 action level applies to each system's result, not to this average)

Why children are most at risk: The CDC states that no safe blood lead level in children has been identified. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.

No safe blood lead level in children has been identified, according to CDC, so an area average under 0.010 mg/L does not rule out exposure at home. In Rancho Santa Margarita, 23% of homes were built before 1986.

Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.

Deep Dive Reports

Detailed analysis for Rancho Santa Margarita, CA

Frequently Asked Questions

What does the Home Safety Score mean for Rancho Santa Margarita, CA?
Rancho Santa Margarita has an average Home Safety Score of 92/100 (Grade A) under ZipCheckup model 4.0.0, an area-level model that draws on EPA water compliance records, PFAS screening, EPA radon zones, and annual EPA air quality data; see the methodology page for how inputs and coverage are handled. The available EPA record reports no violations for ZIP codes with reported counts. Check individual ZIP code reports for component details.
Does Rancho Santa Margarita water have lead?
The average of the reported 90th-percentile lead results across the ZIP codes of Rancho Santa Margarita is 0.0039 mg/L. The EPA action level of 0.015 mg/L applies to each water system's own 90th percentile, not to this average. EPA's health goal for lead is zero. Lead levels can vary by home - testing is recommended especially in older properties.
How does Rancho Santa Margarita compare to California average?
Rancho Santa Margarita has an average Home Safety Score of 92/100, which is at or above the California state average of 76/100 for the same model series.
How many water systems serve Rancho Santa Margarita?
Our records map 2 water systems to 1 ZIP code in Rancho Santa Margarita. The related population figure in our data is approximately 43,937 people; it is not a count of people served citywide.
Home → Cities → California → Rancho Santa Margarita, CA

How to cite this page

APA ZipCheckup. (2026). Rancho Santa Margarita, CA Home Safety: Home Safety 92/100. https://zipcheckup.com/cities/ca/rancho-santa-margarita/
BibTeX 
@misc{zipcheckup-cities-ca-rancho-santa-margarita,
  author = {{ZipCheckup}},
  title  = {{Rancho Santa Margarita, CA Home Safety: Home Safety 92/100}},
  year   = {2026},
  url    = {https://zipcheckup.com/cities/ca/rancho-santa-margarita/}
}

Page version: October 2026.

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