INTEGRATED URBAN STORMWATER QUALITY MANAGEMENT: FIELD INVESTIGATIONS ATA BEST MANAGEMENT FACILITY

Stormwater discharges from urbanized areas strongly contribute to the impairment of water uses in a number of Areas of Concern in the Great Lakes Basin, and may impede efforts to delist these areas from the Remedial Action Plan program. In a search for solutions to these problems, an interdisciplinary team from the National Water Research Institute and Queen’s University is conducting field-scale research (supported by laboratory studies) designed to characterize stormwater contaminants and their removal by an integrated environmental system centred around an existing stormwater best management facility, an on-line wet detention pond. This facility is appropriate because it is typical of many older ponds: it is on-line, its inadequate size and unfavourable shape prevent effective stormwater quantity and quality control, and it discharges to a downstream sensitive coastal wetland area. The main objective of the research is to develop a combination of cost-effective, operationally-simple methods of providing an acceptable level of stormwater quantity and quality control. The existing pond performance was assessed by producing detailed flow and material balances, and loading characteristics under both baseflow and storm flow conditions. Remedial measures focus on improved pond hydraulics and sediment settling by retrofitted flow baffles, pond effluent polishing by constructed wetlands and a biofilm reactor, and detoxification of pond sediments. A summary of the first three-year phase of the research program is presented in the paper.