Description:
Disposal of sewage solids resulting from wastewater treatment processes has historically been the most difficult and “unsolved” problem in the handling of water-carried wastes in Southern California. Continuing rapid growth combined with Federal laws which essentially prohibit any discharge of sludge to the ocean regardless of net effects upon the land) water and air total environment have exacerbated this problem to an almost critical state. Complex incineration processes directed at producing energy from dried sludge while minimizing negative atmospheric impacts are under construction. Their complexity has resulted in start-up problems related to the short time allowed for design and break-in by Federal Court action. Increased sludge disposal amounts are also resulting from Federal insistence upon full secondary treatment prior to ocean disposal regardless of net environmental impact. Four large facilities were examined: the Sanitation Districts of Los Angeles and Orange Counties, the City of San Diego and the City of Los Angeles. Differing approaches to disposal have been chosen with landfills receiving most sludge at the present and incineration planned for most in the future. Description of the current practices with the amounts of solids to be disposed of and the current costs are outlined.