Sunnyvale, CA Water Safety: 74/100 (2026)
5 ZIP codes · 4 water systems · Updated 2026-06-03
The water systems supplying Sunnyvale show a track record of above-average compliance with federal standards — consistently among the better performers in CA.
How Sunnyvale Compares
Data: EPA SDWIS Last verified: 2026-06-03
Water Quality Map: Sunnyvale, CA
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Score Distribution
Safety grade breakdown for Sunnyvale's 5 ZIP codes.
Key Facts for Sunnyvale Residents
- Homes built before 1986: 62% — older plumbing may contain lead solder.
- Estimated remediation: $1,680 per household.
- CDC health risk index: 9.01.
Sunnyvale's Water Providers
Structurally, Sunnyvale, CA's water supply is divided. Federal data identifies 4 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 5 ZIP codes in Sunnyvale, California (population ~153,455), covering 4 community water systems serving approximately 386,149 people region-wide.
No EPA violations recorded across any ZIP codes in Sunnyvale — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Sunnyvale: B (74/100)
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
Sunnyvale water systems draw from: Surface water.
Lead & Copper
- Lead data: not yet available for Sunnyvale
- 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): 5 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 |
|---|---|---|---|
| 94085 | B | City of Sunnyvale | 157,566 |
| 94086 | B | City of Sunnyvale | 157,566 |
| 94087 | B | City of Sunnyvale | 157,566 |
| 94088 | B | City of Sunnyvale | 157,566 |
| 94089 | B | City of Sunnyvale | 157,566 |
All ZIP Codes in Sunnyvale
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.
Sunnyvale Community Health Snapshot
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
Sunnyvale Infrastructure Age
With 62% 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
When a city's housing median build year is 1979, as in Sunnyvale, the implication for water quality research is straightforward: municipal-level data captures what leaves the treatment plant, but household plumbing from before 1986 determines what actually arrives at the tap. In cities where older housing predominates, that gap between system-level and household-level data is widest.
Over half of homes in Sunnyvale were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
How Remediation Costs Compare in Sunnyvale
In Sunnyvale, property wealth outpaces what documented remediation typically demands — the equity burden lands well within the low tier.
Remediation costs in Sunnyvale are relatively low compared to home values. The $840–$2,700 estimated range is a small fraction of median property value. Home values are 142% above the California average.
Sunnyvale: Lead Risk & Vulnerable Populations
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 62% pre-rule share in Sunnyvale 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.
Sunnyvale: Flood History & Water Damage Risk
Flood risk in Sunnyvale occupies the middle ground: 15 NFIP claims and 80% of local ZIP codes within FEMA flood zones. At that level, the risk pathways connecting flooding to water quality — treatment system stress, well infiltration, distribution backflow — become relevant considerations during significant flood events, even if day-to-day water quality is unaffected by flood history.
Sunnyvale has a moderate flood history with 15 FEMA claims averaging $6,317 per payout. 80% 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>$1,680</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 Sunnyvale, CA