Field Investigation and Modeling of Metal Transport and Fate in a Coastal Watershed by DYNHYD5 and WAS

Water pollution in coastal watersheds due to the introduction of toxic substances from industrial discharges, land, and storm drains has been a growing concern for both the public and governments. Over the years, great efforts have been paid by engineers and researchers to study the transport and fate of pollutants within a watershed in order to evaluate the impacts of water pollution on human and aquatic life. However, fewer studies have been undertaken to investigate the applications of water quality models to coastal watersheds, particularly to model the transport and fate of metals. This research proposed an integrated water quality monitoring and modeling approach for coastal waters. The approach is applied to the Nut Brook and Kelligrews River, a local watershed in Newfoundland. Intermittent field monitoring and sampling have been conducted in a number of sites within the watershed since 2006 for pollution source identification and data collection. In order to compensate the limitations existing in the intermittent field sampling and monitoring, a hydrodynamic model (DYNHYD5) and a water quality model (WASP) were utilized for hydrodynamic and water quality simulation of metals in the watershed. The selected models are found to be quite effective in simulating the trends of concerned pollutants levels over the entire study time period. Based on the results from field investigation and water quality monitoring and modeling, a number of recommendations were made to the local authorities for facilitating water pollution control and quality management practices.