Mendota, CA Water Safety: 75/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Looking at federal monitoring data for Mendota, CA: the city clears benchmarks set under the Safe Drinking Water Act with room to spare — recorded exceedances are rare, and the systems serving local households have not triggered any pattern of repeat deficiencies in recent cycles.
How Mendota Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Mendota Water
- Homes built before 1986: 34% — older plumbing may contain lead solder.
- Estimated remediation: $1,600 per household.
- CDC health risk index: 12.33 — above typical levels.
Who Supplies Your Water in Mendota
2 water systems are tracked federally in Mendota, 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 1 ZIP code in Mendota, California, covering 2 community water systems serving approximately 14,507 people.
No EPA violations recorded across any ZIP codes in Mendota — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Mendota: B (75/100)
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
Mendota water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Mendota
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 93640 | B | City of Mendota, | 11,404 |
All ZIP Codes in Mendota
- 93640 [B]
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 Mendota
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 Mendota
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
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 1995 places Mendota 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 Mendota 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 Mendota Homeowners
Placing remediation in the context of Mendota's property market, the equity share is low — most homeowners here are weighing a financial commitment that fits comfortably within routine property planning, far from the threshold where remediation becomes a material equity decision rather than a standard upkeep consideration.
Remediation costs in Mendota are relatively low compared to home values. The $800–$2,600 estimated range is a small fraction of median property value. Home values are 65% below the California average.
Lead Exposure Risk for Children in Mendota
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 34% of housing dates from the pre-rule era and citywide monitoring sits at or above the regulatory mark in Mendota.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Mendota
Across the multi-decade NFIP record, Mendota shows a claim tally well below the thresholds where flood exposure typically enters active infrastructure-risk discussions. Flooding can disrupt water quality when events are large enough to overwhelm treatment systems or contaminate private wells, but that scenario remains a low-probability edge case for communities at this claim level.
Mendota has a relatively low flood history with 4 FEMA claims on record. While risk is limited, severe weather events can still impact water infrastructure.
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>$1,600</strong> remediation cost per household.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
Deep Dive Reports
Detailed analysis for Mendota, CA