Biosolids are the stabilized residuals that is created after the wastewater treatment process. Salish Soils only accepts biosolids, not sludge from septic tanks or porta potties. Salish Soils accepts Biosolids from the Town of Gibsons and the District of Sechelt, both of which were previously being land applied without further treatment or transported off coast.

After transported to Salish Soils site, the biosolids are prepared for the composting process to create Class A compost. After being mixed with the proper amount of carbon and water, the mixture is placed in aerated channels and covered with a membrane utilizing Gore technology. The carbon source is from ground up Green Waste dropped off at Salish Soils from residential and commercial customers.

The mixture is constantly monitored, and the air flow is adjusted to reach OMRR (Organic Matter Recycling Regulation of British Columbia) guidelines of 55°C for a minimum of three days to kill weed seeds and pathogens. The mixture is flipped after 2 weeks to reintroduce oxygen, and if required, additional water is added. After an additional 2 weeks, the mixture is removed from the bay and placed in curing piles for a minimum of 5 months. After curing, the mixture is screened to remove the larger woody material, and any other potential contamination that may have been introduced, and is now ready to be sold. The entire compost process takes a minimum of 6 months to achieve Class A compost.

The Biosolids Compost is used to make Bio soil which is mixture of Biosolids Compost and Sand, and is designed for lawns and turf seedling.

Salish Soils is constantly working on improving products and is currently exploring the idea of creating a garden soil utilizing biosolids compost.