Drinking Water Compliance OS

CHICO, CA · Colusa County

DEL ORO WATER CO.-WALNUT RANCH Water System

Inactive system

This water system is marked inactive in EPA’s federal records as of December 15, 2015. It is no longer an operating public water system under this PWSID, and no compliance deadlines — including the 2027 Consumer Confidence Report rule — apply to it.

If you are a resident looking for your current water provider, see water systems in Colusa County, CA.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed July 4, 2026. This is a record-keeping and public-information tool — it does not replace California’s official records. Always confirm current status with California before making decisions based on this information.

System facts

System ID (PWSID)
CA0600011
System type
Community Water System
Population served
182
Service connections
78
Ownership
local government
Water source
groundwater (wells)

Violation history

  • Maximum Contaminant Level Violation, Average

    Health-based

    Arsenic

    July 1, 2010 – September 30, 2010

    Resolved
  • Maximum Contaminant Level Violation, Average

    Health-based

    Arsenic

    April 1, 2010 – June 30, 2010

    Resolved
  • Notification, Public

    No contaminant on record

    December 1, 1982 – December 31, 1982

    Archived
  • Monitoring, Regular

    Gross Alpha, Excl. Radon and U

    October 30, 1980 – October 29, 1981

    Archived

Resolved addressed and confirmed by the stateArchived closed in EPA's records (typically due to age or a data correction)

Enforcement actions

Last known contact on file (system is inactive)

FORTINO, ROBERT

530-809-3970

CHICO, CA 95927