Using Optical Properties of Dissolved Organic Matter to Discriminate Sewage Treatment Effluents from Runoff in Santa Monica Bay, California

Abstract

The Hyperion Treatment Plant (HTP) located off Santa Monica Bay is the largest sewage treatment facility in the Los Angeles Metropolitan Area. In order to perform necessary repairs chlorinated secondary-treated effluents were temporarily diverted from the 5-Mile Outfall to the 1-Mile Outfall. To monitor the environmental impacts, the city of Los Angeles established a program. My project assisted with distinguishing effluent dissolved organic matter (DOM) from terrestrial-runoff DOM based on chemical analysis, and optical properties of DOM. Samples were collected weekly during Fall 2015 and were analyzed for CDOM absorption spectra (250-700 nm), EEM fluorescence, concentrations of dissolved organic carbon and total dissolved amino acids. This data set complemented existing water quality analysis products, and provided critical data for the development of remote sensing approaches.