Wastewater treatment and risk assessment in ocean outfall evaluations

Abstract

Past evaluations of the success of wastewater treatment and submarine outfall placement and operation have considered only a limited number of parameters affecting the marine and onshore environments. Important questions regarding the best allocation of available funds have not been adequately addressed. The relative contamination of the sea from airborne and landwash contaminants has not been considered. Neither has the increased air pollution deriving from the energy required for advanced treatment. Similarly, regular epidemiological studies to evaluate actual changes in morbidity arising from drastic changes in treatment and disposal have not been made prior to very large committments of funds. Most importantly, little attention has been given to the relative ranking of all environmental risks within a catchment area. The net result is that, when all factors are considered, the very large expenditures and increased energy use for sanitary wastewater treatment and outfall disposal will have a net negative effect on the physical and societal environment. The City of Los Angeles and the Los Angeles Metropolitan area can be used to illustrate this probability.