Hayward, CA Water Safety: 82/100 (2026)
7 ZIP codes · 5 water systems · Updated 2026-06-03
Tap water in Hayward, CA scores well — low violation counts, above-average safety grade.
How Hayward Compares
Data: EPA SDWIS Last verified: 2026-06-03
Water Quality Map: Hayward, CA
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Score Distribution
Distribution of water safety grades across Hayward.
Hayward Water: The Quick Version
- Average lead level: 0.0016 mg/L.
- Estimated remediation: $1,643 per household.
- CDC health risk index: 9.67.
Water Systems Serving Hayward
Residential addresses in Hayward, CA are served by 3 primary water providers out of 5 systems in federal records. Each system maintains separate infrastructure and files its own EPA compliance reports, so service conditions are not uniform across the city.
Overview
We track water quality and home safety data for 7 ZIP codes in Hayward, California (population ~192,439), covering 5 community water systems serving approximately 1,949,920 people region-wide.
No EPA violations recorded across any ZIP codes in Hayward — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Hayward: B (82/100)
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
Hayward water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0016 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 7 ZIP codes
- Zone 3 (Low): 0 ZIP codes
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 94540 | B | City of Hayward | 162,954 |
| 94541 | B | City of Hayward | 162,954 |
| 94542 | B | City of Hayward | 162,954 |
| 94543 | B | City of Hayward | 162,954 |
| 94544 | B | City of Hayward | 162,954 |
| 94545 | B | City of Hayward | 162,954 |
| 94557 | B | City of Hayward | 162,954 |
All ZIP Codes in Hayward
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 Hayward
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
Hayward: Remediation Cost in Perspective
Low proportionality — that's the Hayward picture when remediation costs are placed against typical home equity.
Remediation costs in Hayward are relatively low compared to home values. The $829–$2,700 estimated range is a small fraction of median property value. Home values are 14% above the California average.
Protecting Children from Lead in Hayward
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 Hayward 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 Hayward
Flood exposure in Hayward is meaningful by NFIP measures — 38 claims on record and 57% of ZIP codes carrying FEMA flood zone designations. That level of activity makes flood history a relevant factor when evaluating local water quality over time.
Hayward has a moderate flood history with 38 FEMA claims averaging $23,001 per payout. 57% 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>$1,643</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 Hayward, CA