The City of Santa Rosa Biosolids Value Chain (BVC) is a system unique to the Laguna Treatment Plant (LTP). The diagram below shows the flow of wastewater into the collections system and the steps leading to biosolids end use. The treatment process begins before the wastewater reaches the treatment facility. Industrial facilities are required to pre-treat their wastewater to remove contaminants before discharging into the public wastewater system. Once the wastewater enters the plant through the collection system solids and liquids are separated. The Solids go through the steps shown below in the BVC and sewage sludge is treated and turned into Class B biosolids.

Class B biosolids are disked  into the ground and lime is added if needed (Land Application Sites). The City spreads Class B biosolids mainly as a soil amendment for fodder crops. The regulations are monitored by the Sonoma County Environmental Health Department to ensure that biosolids are spread according to the agronomic rate set by Title 40 CFR Part 503.

A portion of the biosolids produced at LTP are taken to the Laguna Compost Facility and are further processed into high-grade compost, also known as Class A Compost.