Water Quality Modeling in New York/New Jersey Harbor: A Historical Perspective on the Present

As HydroQual celebrates its 25th Anniversary as a corporation based in the New York-New Jersey metropolitan area, it is appropriate to reflect upon water quality in the New York-New Jersey Harbor. The waters of the New York/New Jersey Harbor complex provide a valuable resource to the New York metropolitan area and to the nation in general. Given the rapid growth in urban population, industrial development, and shipping and commerce within the region over the past three hundred years, it is not surprising that the waters of the Harbor have shown evidence of degraded water quality and significant environmental stress. Efforts to mitigate these problem have included a combination of regulatory controls and wastewater treatment plant construction. These efforts, which have largely taken place over the past forty to fifty years, have led to measurable and significant beneficial improvements in water quality. Mathematical, or numerical water quality, models have been a key tool for providing water quality managers insights into the relationships between pollutant inputs and water quality responses in the Harbor. The spatial resolution and environmental complexity of water quality modeling has grown from relatively simple steady-state, one-dimensional, coliform and BOD/DO models to complex time-variable, three-dimensional models, which include hydrodynamic, sediment transport, complex eutrophication/organic carbon production, contaminant fate and transport, and bioaccumulation frameworks. Beyond the New York/New Jersey Harbor, these frameworks are applicable to many urban waterways