States ›California ›Sonoma County ›Larkfield-Wikiup

Larkfield-Wikiup, CA Tap Water Quality 2026

Water quality report for Larkfield-Wikiup, CA — PFAS, lead and copper results, violation history and state inspection findings from EPA SDWIS.

A look at Larkfield-Wikiup's drinking water using EPA enforcement records: violations, lead and copper results, PFAS sampling and state inspection findings.

Main Utility: California-American Larkfield (puc) PWSID: CA4910023 Updated: 2026 Q2
✅

No federal limits exceeded on record

Lead is 6.00 ppb, 40% of the action level and no violations are open. No PFAS was detected.

A

Larkfield-Wikiup earns an A for water quality

Graded on violations, lead, and PFAS, with state inspection findings.

Lead: 6.00 ppb — 40% of the federal action level
PFAS tested, none detected
No violations since 2015
No violations currently open
Larkfield-Wikiup's lead level vs. all California community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 6.00 ppb — 40% of the federal action level
✓ Lower lead than 12% of California utilities
Population Served
7816
~2398 connections
Water Source
Groundwater
Drawn from wells — SDWIS source code GW
Active Violations
0
None on record since 2015

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
40% of EPA action level
6.00 ppb
Action level: 15 ppb
The 90th-percentile lead result is 6.00 ppb, 40% of the 15 ppb federal action level. The action level is a treatment trigger, not a legal maximum, and it is measured across sampled taps rather than at any single home.

Contaminant Violations (2015–Present)

✓ No violations on record for this water system.
Understanding violation types MCL violations mean a contaminant exceeded the federal maximum limit — the most serious type.
TT (Treatment Technique) violations mean required treatment procedures weren't followed, but don't necessarily mean contamination occurred.

Violation History

No violations are on record for this system since 2015. EPA records violations for every community water system, so this reflects a clean compliance history rather than missing data.

About the Main Water System

Utility California-American Larkfield (Puc)
PWSID CA4910023
Water source Groundwater — Drawn from wells — SDWIS source code GW
Population served 7,816
Service connections 2,398
Systems serving this area 5
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Larkfield-Wikiup tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open. Lead is 6.00 ppb, 40% of the action level.
Does Larkfield-Wikiup water have PFAS? ▼
It was tested for the six regulated PFAS compounds and none were detected.
Who supplies water to Larkfield-Wikiup? ▼
California-American Larkfield (Puc) (PWSID CA4910023), one of 5 systems serving this area. Groundwater. Drawn from wells — SDWIS source code GW
When was this system last inspected? ▼
It was last inspected on 2026-03-11. No significant deficiencies were recorded.

What Should Larkfield-Wikiup Residents Do?

1
Consider a filter certified for lead
Look for NSF/ANSI 53 certification for lead reduction.
2
Check for a lead service line
Lead reaches tap water mainly through service lines and household plumbing. Suppliers now publish an inventory identifying lead lines.
3
Flush before drinking
If water has sat in pipes more than six hours, run the cold tap for two minutes before drinking or cooking.

Nearby Cities in California

Santa Rosa, Ca Tap Water Quality 2026 Sonoma Petaluma, Ca Tap Water Quality 2026 Sonoma Rohnert Park, Ca Tap Water Quality 2026 Sonoma Windsor, Ca Tap Water Quality 2026 Sonoma Healdsburg, Ca Tap Water Quality 2026 Sonoma Sonoma, Ca Tap Water Quality 2026 Sonoma