At Tuesday’s board meeting, the Sonoma County Supervisors approved two measures concerning Sonoma Valley County Sanitation District. The first item allows for a low-interest loan to complete a biosolids management upgrade project in the Valley. The project is currently estimated to cost $2.9 million.
The second item approved another low-interest loan by the district to complete a main sewer trunk replacement from Watmaugh Road East to the treatment plant. The cost for this project is estimated to be $4.1 million. It is intended to repair and improve the existing main sewer trunk to reliably handle dry and wet weather inflows, enhance wet weather capacity and reliability, and improve surface water quality within the District.
The monies for both projects are provided through State Revolving Fund (SRF) loans.
The district operates a wastewater collection system within Sonoma Valley that serves a 4,500-acre service area and more than 17,000 single-family dwellings. The district treatment facility removes solids from the liquid wastewater stream. In the treatment facility’s extended aeration stabilization process, the solids are extracted, dewatered, and converted into Class B biosolids. These biosolids are currently hauled away and disposed of at a municipal landfill. Additionally, the solids handling equipment is aging and there are some operational inefficiencies with the current system. The district also has one of the higher biosolids processing and disposal costs in the San Francisco Bay Area.
