Contaminant Transport and Spill Reference Tables for the St . Clair River

l The goal of this work is to calibrate a real-time hydrodynamic model for spill tracking in the St. Clair River and to provide decision makers with information for response planning and in the event of a spill. In order to provide experimental validation data, three dye releases were carried out to simulate movement of a potential contaminant in the river. Measurements of dye concentration were used to provide estimates of lateral and vertical mixing as well as travel time of the dye cloud. Model simulations were able to recreate the dye movement and concentrations with model-estimated arrival times within 14 min of the observed plume arrival times and concentrations within 0.005 normalized concentration units of the observed concentrations (which ranged from 0.06 to 0.004). Following model calibration, a set of spill scenarios was chosen to encompass the types and locations of spills commonly experienced in the St. Clair River. These spill scenarios were then simulated with the HECWFS model to predict transport characteristics such as plume leading edge travel time, duration, concentration, and cross-channel mixing. Results from the scenarios were compiled into reference tables in which spill characteristics are listed at several downstream transects. These spill reference tables provide water intake operators with information before the event of a spill, enabling decision makers to plan for potential or common spills as well as providing a quick reference library that can be accessed immediately after a spill is detected to aid in mitigating the effects on drinking water supply.