Development of the Fecal Coliform Total Maximum Daily Load Using Loading Simulation Program C~(++) and Tidal Prism Model in Estuarine Shellfish Growing Areas: A Case Study in the Nassawadox Coastal Embayment, Virginia

摘要

In this study, a linked model system including the Loading Simulation Program C~(++) (LSPC) and the tidal prism water quality model (TPWQM) was proposed as an alternative tool for total maximum daily load (TMDL) studies. The feasibility of the model system was tested by a case study in the Nassawadox Creek, a Virginia tidal water shellfish growing area. The watershed model, driven by hourly precipitation, simulates hydrology and fecal coliform accumulation and transport processes in the watershed. The simulated surface runoff and subsurface flow as well as fecal coliform loads from the watershed are discharged to the tidal creek. The tidal prism model simulates fecal coliform transport in the Creek. The model results demonstrate the effectiveness in simulating hydrology and fecal coliform concentration in the watershed and its embayment. A series of sensitivity runs was conducted to estimate the load reduction necessary for fecal coliform concentration to meet the water quality standards. The model application to the Nassawadox Creek indicates that the model system is useful in developing fecal coliform TMDLs for estuarine shellfish growing areas.