ENHANCING THE REMOVAL OF POLLUTANTS BY AN ON-STREAM POND

A methodology is presented for assessing the pollution control perform ance of an on-stream pond located in Kingston, Ontario, Canada, and en hancing the removal of pollutants by remediation techniques., Descript ions are provided of the instrumentation used to measure continuously rainfall and water levels, and the sampling program to collect stormwa ter samples., The assessment is based on examining contaminant removal s for both baseflow and event conditions and applying in-pond remedial measures to improve pond performance., Results on removal rates are p rovided for selected dissolved constituents (total dissolved solids, s ulphate and chloride), nutrients, suspended solids, metals and organic contaminants., In summary, dissolved constituents exhibit zero remova l for baseflow periods and positive removal for events; nutrients and suspended solids exhibit negative removal for baseflow periods and pos itive removal for events; and metals and organics exhibit positive rem oval for both baseflow periods and events. Remediation techniques are discussed and preliminary results of one technique - internal pond baf fles - indicate that extended hydraulic residence times and prevention of flow short-circuiting result in increased particulate settling and associated contaminant removal. Copyright (C) 1996 IAWQ.