Digesters - egg shaped
Solids removed during primary and secondary treatment are pumped to these huge, egg shaped vessels. Terminal Island digesters were the first ever egg-shaped - built in 1985. The shape is particularly efficient for the digestion process and creating a large capacity on a small footprint. Bacteria living in this warm, oxygen-free space digest the solids. The bacteria, along with the heat, destroy virtually all pathogens and release a biogas (methane) that is processed for energy recovery. The biosolids that are processed here are considered Exceptional Quality, which is a pathogen-free Class A organic product, suitable for many landscaping and agricultural applications.