A
95

Record-only indicator: A

Not a safety rating. Missing or old measurements can produce a high score.

Coverage: 3/3 mapped systems have a dated lead result; 0/3 have copper results; 3/3 have UCMR monitoring.

Sunnyvale, CA 94086

Santa Clara County · Population served: 157,566 · SDWIS 2026-07-21 · UCMR5 August 2026

Service-area evidence: EPA service-area records associate the listed system with this ZIP. Boundaries may still overlap or change.

Water Systems Serving This Area

🏔
CITY OF SUNNYVALE
Surface water · Pop. 157,566

Lead: 0.0 ppb; period end 12/31/2025. Copper: not available ppb; period end unknown.

PWSID: CA4310014
🏔
CWSC LOS ALTOS SUBURBAN
Surface water · Pop. 69,973

Lead: 1.5 ppb; period end 12/31/2025. Copper: not available ppb; period end unknown.

PWSID: CA4310001
🏔
BRYAN CO. RWS & SWMD #2
Surface water · Pop. 6,270

Lead: 0.564 ppb; period end 12/31/2024. Copper: not available ppb; period end unknown.

PWSID: OK1010604

Reported lead and copper results

ContaminantReported value or boundHistorical comparison valueInterpretationStatus
Lead
1.5 ppbPeriod end: 12/31/2025
15 ppb Largest reported value or bound among mapped systems; not necessarily the largest actual concentration. At/below comparison value

PFAS / Forever Chemicals

1 detected Below comparison values

UCMR5 occurrence results are screening information, not a finding of regulatory compliance or noncompliance. PFAS rules and compliance dates are evolving.

CompoundLevelEPA MCLInterpretationStatus
PFHxS3.5 ppt10 ppt10 pptBelow comparison value

Violation History (Last 5 Years)

8Total (5yr)
2Health-Based
3Major

Public-record summary

Understanding Your Water in Sunnyvale

Record-only indicator — incomplete or old records can produce a high score. A score of 100 is not a safety finding. Coverage: 3/3 mapped systems have a dated lead result; 0/3 have copper results; 3/3 have UCMR monitoring. Tap water quality in Sunnyvale, California (94086) receives an record-only indicator of A (Lower record-based concern) with a score of 95 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is roughly in line with the California state average of 92. The area is served by 3 water systems providing water to approximately 157,566 people, using surface water sources. PFAS testing detected 1 compound, all below the EPA final MCL values used for comparison. Over the past 5 years, water systems here have accumulated 8 violations, including 2 health-based violations.

Record-only score 95/100 A
vs State ▲ 3 pts above California avg (92)
Comparison limits No national safety ranking: coverage and service areas overlap.

What a Grade A Means

Grade A summarizes the records available to this model, not household safety. Missing, bounded or old measurements can produce a high score, including 100. Review coverage, dates and the current utility report before interpreting this indicator.

Surface water: sourced from rivers, lakes, or reservoirs

Health Information

What These Contaminants Mean for You

⚠️

Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

Common Questions

Frequently Asked Questions

The record-only indicator is A (95/100). It cannot determine whether your tap water is safe. Missing, bounded or old measurements can produce a high score. Check the coverage and sampling dates below and your utility's current notices.

ZIP code 94086 is served by 3 water systems using surface water sources, providing water to approximately 157,566 people. Surface water systems are more susceptible to contamination from agricultural runoff, industrial discharge, and weather events, but typically undergo more extensive treatment including filtration and disinfection.

The largest reported lead value or bound is 1.5 ppb, for the sampling period ending 12/31/2025. This is a system-level 90th-percentile record, not a measurement at your tap. Compare the sampling date and original utility report before interpreting it.

1 PFAS compound were detected in water serving Sunnyvale, California, with no result above the individual comparison values shown here; some compounds have no individual federal MCL. This comparison is informational: federal compliance timelines and the status of some PFAS standards are still evolving. Activated carbon or reverse osmosis filters can reduce some PFAS when appropriately certified and maintained.

Water systems serving Sunnyvale, California have received 8 violations in the last 5 years, including 2 health-based violations. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.

This public-record indicator cannot select household treatment. Confirm your supplier, current utility report and tap-testing results first; match any treatment to a certified contaminant-reduction claim and follow its maintenance instructions.

Explore Nearby

Water Quality in Nearby ZIP Codes