Airport/Larkfield/Wikiup Sanitation Zone

    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 Barry Dugan at or (707) 547-1930.

    Latest Updates on Sewer Extension Construction  

    (6/29/18) Geotechnical Assessment Gets Underway with Borings

    Crews from GHD, the engineering firm designing the sewer collection system, were in the Larkfield Estates neighborhood on Friday, June 29 (see photos below). They worked with drillers from Clear Heart Drilling to conduct geotechnical borings at six locations. The soil samples gathered from the borings will undergo laboratory testing as part of the environmental site assessment that will analyze soil integrity and the presence of any potential contaminants.

     At top left and top right, drill operators extract soil samples at a site on Lambert Drive, west of Ursuline Road. At bottom left, Ryan Crawford, geologist with GHD, discusses a soil sample with one of the drilling operators. At far right, GHD geotechnical engineer Dave Mebrahtom labels a soil sample that will go to the laboratory for analysis.


    (6/20/18) Site Assessment Work Scheduled

    Crews from GHD (the engineering firm designing the sewer collection system) will be in the Larkfield Estates and Ramsgate Court neighborhoods on Friday June 22nd to mark utilities and mark the six geotechnical boring locations. After the boring locations and underground utilities are marked, a drilling crew is anticipated to be on site starting June 29 to drill the borings. During that time, soil samples will be also be taken for laboratory testing as part of the environmental site assessment. View a map of the proposed boring locations

    (6/18/18) June 2018 Community Update

    Updates about the hiring of a sewer collection system design consultant, an estimated sewer design timeline,  financing loan order, and a new Water Agency point-of-contact.


    Proposed Sewer Lateral Ordinance For Airport/Larkield/Wikiup Sanitation Zone

    The Sonoma County Water Agency (Water Agency) will hold a series of community meetings to discuss a proposed sewer lateral ordinance aimed at preventing sewer overflows that occur during heavy rains. The ordinance would apply to the Russian River and Occidental County Sanitation Districts, and the Airport/Larkfield/Wikiup, Geyserville, and Sea Ranch Sanitation Zones, all of which are operated by the Water Agency.

    The ordinance would provide the Water Agency with the ability to inspect, and if necessary, require the repair of sewer laterals that are failing and contributing to pollution and sewer overflows. The proposed ordinance will NOT require any point-of-sale sewer lateral inspections or repairs. The proposed ordinance would not include a mandatory inspections program, but if faulty laterals are detected during routine inspections, the Water Agency could require repairs. An inspection could also be required if a main sewer line that is connected to the lateral is being replaced or rehabilitated. The ordinance is proposed in five sanitation zones and districts the Water Agency manages in Sonoma County. Read more ...

    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

    Front Desk (Monday-Friday, 8:00am-5:00pm PST): 707-526-5370
    Operations Desk (24 Hours): 707-523-1070