Airport/Larkfield/Wikiup Sanitation Zone

    About the District

    • Began Operation:1983
    • Service area: 2,100 acres
    • Service recipients: 3,464 Equivalent Single-Family Dwelling
    • Treatment level: Tertiary
    • Design capacity: 900,000 gallons per day (average daily dry weather flow)
    • Discharge: All of the recycled water is used for irrigation.
    • Board of Directors:  The Water Agency's Board of Directors act as the District's Board.


    Newsletter and Proposition 218 Notice


    Budget Information


    Contact Information

    Douglas Messenger, 707-547-1952 or



    Larkfield Estates Neighborhood Sewer Connections

    The neighborhood of Larkfield Estates, which was heavily impacted by the October 2017 Sonoma Complex Fires, lies within the boundary of the Airport/Larkfield/Wikiup Sanitation Zone (ALWSZ) and is therefore eligible to connect to sewer service.  As the neighborhood rebuilds, property owners may be interested in pursuing sewer connection for their properties.  In order to connect homes in Larkfield Estates to the ALWSZ a sewer collection system needs to be designed and built, and property owners would need to pay the ALWSZ connection fee.

    After being approaches by property owners in Larkfield Estates, the Water Agency is developing a program to extend sewer service to the neighborhood for voluntary connection and to develop a financing program for property owners interested in connecting to sewer.

    More Information about Larkfield Estates Sewer Extension and Financing Program

    Questions?  Please contact Sophie Porcelli at or (707)524-6430.