Using real time observing data for public health protection in ocean waters

Historically, ocean water quality surveillance tools for the protection of public health have been hindered by the lag time between sample collection and results. For beaches near known or on-going sources of contamination, the test method limitations leave the health department with few options. The department can either continue to make decisions based upon yesterday's data (which may no longer be valid), or permanently close the beach to ensure the protection of public health.

This is the dilemma that exists in Imperial Beach, California, one mile north of the Tijuana Estuary mouth. During and after rain, sewage contaminated flows in the bi-national Tijuana River will enter the United States and Tijuana Estuary. Knowing exactly when and what direction ocean currents are moving is essential to provide accurate beach closure information and prevent unnecessary economic hardship on local communities.

The San Diego Coastal Ocean Observing System (SDCOOS) provides the County of San Diego, Department of Environmental Health (DEH) with real time information on the direction of ocean currents at the mouth of the Tijuana Estuary, and a modeled projection of the estuary plume in ocean waters. Understanding and reconciling the discrepancies of modeled data to observed conditions are part of the development of a useful model. An on-going dialogue between DEH, City of Imperial Beach Lifeguards, and the developers of SDCOOS at the Scripps Institution of Oceanography has brought SDCOOS to its latest state.