Monitoring Optical Brighteners in Lynnhaven River Watershed

Currently the Lynnhaven River and its tributaries in Virginia Beach, Virginia are in violation of the State's water quality standards for fecal coliform bacteria and dissolved oxygen in shellfish waters. As a result many segments of the river are listed as impaired on Virginia's 303(d) Total Maximum Daily Load Priority List. The Virginia Department of Environmental Quality (DEQ) has evaluated the water samples and has performed source characterization through a process called Bacterial Source Tracking, or `BST'. The data obtained for the Lynnhaven River Watershed indicate that as much as 25% of the fecal coliform pollution in the closed shellfish areas can be attributed to human sources. To better understand the problem, in 2004 the City of Virginia Beach took the initiative to investigate potential sources of sanitary wastewater that may be entering the Lynnhaven River via the storm drainage system. The City's consultant proposed an innovative technique to monitor human waste signatures. Optical brighteners monitoring (OBM) is a promising new technique to detect the presence or absence of human sewage in receiving waters. This paper will describe OBM as an emerging technique to quickly and cost-effectively facilitate a comprehensive survey of illicit discharge entering the storm sewer system. Furthermore, the paper discusses in-house testing, optimal selection of sites, detailed monitoring, and grab sampling.