Infaunal Patterns in the Vicinity of a Small Coastal Wastewater Outfall and the Lack of Infaunal Community Response to Secondary Treatment

Abstract

In July 1985 the Encina Wastewater Authority began discharging ad- <br /><br />vanced primary treated wastewater into Southern California coastal waters at a <br /><br />depth of 45 meters. This discharge was upgraded to full secondary treatment in <br /><br />October 1988, which resulted in substantial improvements in effluent quality. An <br /><br />eight year monitoring program has recorded the response of the infaunal com- <br /><br />munity to the wastewater discharge and changes in treatment. Except for lower <br /><br />abundance of Amphiodia urtica near the outfall, the wastewater discharge appears <br /><br />to be beneficial to the infaunal community by enhancing diversity. There were <br /><br />no indications of temporal changes related to improved treatment levels.