City of Los Angeles Digested Sludge, Biosolids, and Brine Injection Project

The world’s first full-scale demonstration and successful application of this technology was developed for the City of Los Angeles, Department of Public Works, Bureau of Sanitation. Injection operations commenced in July, 2008, at the Terminal Island Treatment Plant.

Currently, 100% percent of the Digested Sludge generated at this sanitation plant is injected at a depth of about 5000 feet underground. Deep well injection has eliminated the need and cost for dewatering and long-distance truck transport to distance rural counties. In addition to the digested sludge from Terminal Island, the facility is also injecting Biosolids Wetcake transported from the Hyperion Treatment Plant, reducing its much longer distant truck deliveries. Finally the facility is also injecting a portion of the Reverse Osmosis Brine generated by the tertiary treatment process at the plant.

City Operations

The process is monitored with advanced geophysical tools, including downhole pressure sensors, fiber optic temperature sensors, periodic geophysical logging, and offset well fluid and gas sampling. The monitoring and analyses confirm containment in the deep target interval, and have verified CO2 sequestration and methane generation.