CITY REPORT CA

Mission Viejo, CA: 1 Violation - Home Safety 91/100

3 ZIP codes · 6 water systems · Updated

ZipCheckup grade for Mission Viejo: A.

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

Within Mission Viejo, CA, the available records add up to an upper-tier grade; that grade describes records, not the water at a given faucet.

How Mission Viejo Compares

Mission Viejo91/100
California avg76/100
National avg73/100

Data: EPA SDWIS

3
ZIP Codes
6
Water Systems
2
ZIPs Linked to Systems with Violations
A · 91
Avg Safety Score
Zone 3
County Radon Potential (Low)
$984K
Median Home Value
$500
Est. Remediation (0.1% of home value)

What You Should Know About Mission Viejo Water

  • Water systems mapped to your city have 1 violation on record since 2021.
  • Average of reported 90th-percentile lead results: 0.0024 mg/L.
  • Homes built before 1986: 68% - older plumbing may contain lead solder.
  • Estimated remediation: $500 per household.
  • Health risk index (ZipCheckup composite of CDC data): 10.23.

Who Supplies Your Water in Mission Viejo

More than one public water system is linked to Mission Viejo, CA: federal records tie 6 systems to the area, and the 3 with the largest reported service populations are shown below. Which of them supplies a particular address depends on where the property sits, and a water bill or the utility can confirm it.

Overview

We track home safety data for 3 ZIP codes in Mission Viejo, California (population ~93,186), covering 6 community water systems serving approximately 888,468 people region-wide. The EPA snapshots used for this build directly map water systems to 2 of 3 ZIP codes.

2 of 2 ZIP codes with a reported violation count in the available EPA record (100%) have recorded EPA violations. The available record reports no health-based violations for this measured scope.

Home Safety Score

Average Home Safety Score for Mission Viejo: A (91/100)

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

Mission Viejo water systems draw from: Surface water.

Lead & Copper

  • Average of reported 90th-percentile lead results: 0.0024 mg/L (EPA action level: 0.015 mg/L)
  • 0 of 2 ZIP codes with known status exceed the EPA lead action level

Radon Risk

3 of 3 ZIP records with known zones are 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.

Top Contaminants

Contaminant Category Violations ZIPs Affected
Total Trihalomethanes (TTHM) Disinfection Byproducts 3 2

Areas with Most Violations

ZIP Code Safety Score Violations Health-Based System
92691 A 1 0 Moulton Niguel Water District
92692 A 1 0 Santa Margarita Water District

All ZIP Codes in Mission Viejo

Data Sources

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

Health Outcomes in Mission Viejo

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

Top Contaminants in Mission Viejo Water

Total Trihalomethanes (TTHM) 3 violations
Disinfection Byproducts · EPA regulatory level for the contaminant named above: 0.08 mg/L
Increased cancer risk with long-term exposure above the MCL

Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.

Housing & Infrastructure in Mission Viejo

1979
Median Build Year
68%
Built Before 1986
14%
Built Before 1970
Copper
Likely Pipe Material

With 68% of homes built before 1986, lead solder in plumbing is a potential concern. Federal law banned lead solder in drinking-water plumbing in 1986, but many older homes retain original plumbing.

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

Housing Age Profile

Some homes in Mission Viejo predate the 1986 federal restrictions on lead in new pipe and solder, so a tap test is a reasonable step for older homes; median build year: 1979.

1979
Median Year Built
68%
Pre-1986 (lead solder era; lead paint banned 1978)
14%
Pre-1970 (Lead Pipes Risk)
Pre-1970 (14%) 1970–1986 (54%) Post-1986 (32%)

Over half of homes in Mission Viejo were built before 1986, when federal law began restricting lead solder in drinking-water plumbing. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.

Source: U.S. Census Bureau ACS B25034.

Cost Context: What Remediation Means for Mission Viejo Homeowners

Estimated remediation for Mission Viejo is a small fraction of median property value - one percent or less - though the ratio does not describe any single household.

Median Home Value
$983,800
Est. Remediation
$500
Remediation as % of home value 0.1%

Estimated remediation costs in Mission Viejo can be compared with local home values. The $300–$800 estimated range can be set against the median property value; actual costs vary by home. Home values are 33% above the California average.

Lead Exposure Risk for Children in Mission Viejo

68%
Homes Built Before 1986
0.0024
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.

If you have young children or are pregnant, consider testing your home's water - especially if your home was built before 1986.

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

Historical NFIP Claim Context in Mission Viejo

13
Total FEMA Flood Claims
$18,698
Avg Reported Sum With Payment Data
0%
A/V Share of Claim-Record ZIPs

Historical NFIP data for Mission Viejo contains 13 flood insurance claims. Among claims with payment data, the average reported building, contents, and ICC component sum is $18,698. Among ZIP codes with claim records, 0% have an A- or V-family dominant rated zone recorded in those historical claims. This is not a complete current FEMA property-map inventory.

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. The $500 remediation estimate shown here excludes flood insurance and is not derived from NFIP claim count.

Claim count does not establish current property risk. Check the exact address in FEMA's current map and obtain a property-specific insurance quote when relevant.

Source: historical FEMA National Flood Insurance Program (NFIP) claim records. No current FEMA property-map designation is asserted.

Deep Dive Reports

Detailed analysis for Mission Viejo, CA

Frequently Asked Questions

What does the Home Safety Score mean for Mission Viejo, CA?
Mission Viejo has an average Home Safety Score of 91/100 (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. 1 violation appears in EPA records for water systems mapped to these ZIP codes. Check individual ZIP code reports for component details.
How many violations are on record for water systems serving Mission Viejo?
EPA records list 1 EPA violation for Mission Viejo water systems. These water-system violations are shown for 3 mapped ZIP codes.
Does Mission Viejo water have lead?
The average of the reported 90th-percentile lead results across the ZIP codes of Mission Viejo is 0.0024 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 Mission Viejo compare to California average?
Mission Viejo has an average Home Safety Score of 91/100, which is at or above the California state average of 76/100 for the same model series.
How many water systems serve Mission Viejo?
Our records map 6 water systems to 3 ZIP codes in Mission Viejo. The related population figure in our data is approximately 93,186 people; it is not a count of people served citywide.
How much does it cost to fix water issues in Mission Viejo?
Estimated remediation cost per household in Mission Viejo: $500; modeled range $300 to $800. Estimated costs may include filtration, pipe replacement, radon mitigation, or flood protection where applicable.
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How to cite this page

APA ZipCheckup. (2026). Mission Viejo, CA: 1 Violation - Home Safety 91/100. https://zipcheckup.com/cities/ca/mission-viejo/
BibTeX 
@misc{zipcheckup-cities-ca-mission-viejo,
  author = {{ZipCheckup}},
  title  = {{Mission Viejo, CA: 1 Violation - Home Safety 91/100}},
  year   = {2026},
  url    = {https://zipcheckup.com/cities/ca/mission-viejo/}
}

Page version: October 2026.

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