A Day at the Beach in Polluted Water

By Manuel Torres III

This article is interesting because it explains how enclosed beaches which are a popular location that families visit annually are hot spots of fecal indicator bacteria (FIB) pollution that emerge from point sources (sewage outfalls and storm drains) and nonpoint sources (decaying vegetation and runoff from drains). The tradeoff is that these enclosed beaches were established to protect against winds and waves; however, it has been analyzed that these beaches are more polluted than beaches impacted by storm drain outlets or along open coastlines. Hence, the investigators focused on the enclosed beaches in Newport Bay, Southern California and investigated the impact of urban irrigation runoff from storm drains. To perform their study, they reported the concentrations of FIB in irrigation runoff, identified spatiotemporal patterns of nearshore FIB and salinity, and evaluated the role of tides, winds, turbulence, and buoyancy on FIB mixing and transport. They concluded that the best option to improve beach water quality in Newport Bay and other urban-impacted enclosed beaches are by outdoor water conservation and urban retrofits that minimize the volume of dry and wet weather runoff entering the local storm drain system. Managers and researchers focused on improving water quality at enclosed beaches worldwide would find this study useful.

Figure 1. Beach water quality studies conducted in Newport Bay, California. Taken from the journal article, "Small Drains, Big Problems: The Impact of Dry Weather Runoff on Shoreline Water Quality at Enclosed Beaches."

 

Reference

 

M. A. Rippy, R. Stein, B. F. Sanders, K. Davis, K. McLaughlin, J. F. Skinner, J. Kappeler, and S. B. Grant. 2014. Small drains, big problems: the impact of dry weather runoff on shoreline water quality at enclosed beaches. Environmental science technology. 48:14168-14177.