Modelling leachate quantity and water quality at landfills

摘要

The Condie and Regina aquifers underlay the City of Regina and supply both industrial and residential water. The city operates a sanitary landfill which is producing a leachate entering the Condie aquifer and may eventually enter the Regina aquifer. In Saskatoon, the University of Saskatchewan operated a chemical landfill which also produced a leachate entering into the Forestry Farm aquifer and eventually the Saskatchewan River. Using the Hydrologic Evaluation of Landfill Performance, (HELP model), both landfills are modelled and evaluated in terms of leachate production. The contaminated aquifers are then modelled using the USGS Method of Characteristics (MOC) program to determine the movement of the contaminant plume. For the Condie, chlorides were modelled, while chloroform was used in the Forestry Farm aquifer because of their low partition coefficients. Travel time is also estimated for contaminated waters of the Condie aquifer to reach the virgin waters of the Regina aquifer.;The study showed that the HELP model was able to predict leachate quantity from two landfills with possible error of 30% to 40%. The MOC model was found to provide reasonably good results of the movement of contaminant concentration plumes in both the Condie and Forestry Farm aquifers.