Assessment of Sediment Ponds to Protect Receiving Waters – Richmond Hill, Ontario



This monitoring and modeling study was conducted by Ryerson University and Clarifica Inc. on a temporary erosion and sediment control pond draining a residential catchment under construction in the Town of Richmond Hill.  The pond incorporates active and permanent pool storage to detain and discharge runoff over an average of 48 hours.  A series of events were monitored for suspended solids and particle size distribution during the fall of 2002 and the summer and fall of 2003.  The model was calibrated using monitoring data and helped to answer questions regarding sediment removal over the long term.

Results of this study show that temporary construction sediment control ponds designed to current standards provide significant removal of suspended solids.  However, due to high influent concentrations and fine particle sizes, effluent concentrations remain elevated at levels that could result in minor to moderate impacts on fish and fish habitat downstream of the facilities.

For final results on this project, see the report entitled Assessment of Construction Sediment Control Ponds to Protect Receiving Waters.