Fate And Transport Of Fecal Indicator Bacteria In The Surf Zone At Huntington Beach, California

Abstract

Solutions to the surf zone pollution have been hampered by incomplete understandings of the mixinghransport and fate of pollutants in the nearshoremixing zone. In this paper, we propose a steady state model to mimic the fate and transport of fecal indicator bacteria (FIB) in the surf zone. The model developed provides insight to the physical and biological processes controlling coastal water quality and specifically, nearshore mixing and inactivation on the pollutant levels in the surf zone. The model inco~orates an analog of the Damkohler number, referred here as a dimensionless number K that indicates whether transport or inactivation is controlling the surf zone pollution. The model successfully explains key feature of fate and transport of FIB in the surf zone as revealed by recent studies in 2000, It is shown that during daytime there was significant amount of sunlight inactivation affecting both influent and effluent FIB concentrations, and at nighttime upcoast transport was controlling FIB concentrations in the surf zone at Huntington Beach, California.