In-situ groundwater treatment using ARUM: IRAP/NRC final report 2000

Abstract

In 1995, after 10 years of monitoring the ground water flow from a small Cu/Zn base metal tailings depositinNorthernOntario,the ground water flow paths were re-evaluated to confirm previously predicted flowdirections. A highly contaminated ground water seepage had taken in 1996 a different route and was emerging to the surface contaminating a small lake (Mud Lake). However the seepage path was well defined hydro-geologically and hence it may be suitable for in-situ-treatment. Geo-microbiological in-situ treatment approaches were considered jointly with Dr. Ferris ( University of Toronto). It was proposed, that through microbial urea degradation ground water pH could be increased, resulting in metal precipitation in-situ improving the seepage discharge quality. A research program was initiated in 1997/98 based on the concept ofin situ-increasing the pH through microbial activity which should result in metal precipitation (Schematic 1). This approach needed to be substantiated with microbiological testing and geochemical modelling. This was carried out by Dr. G. D. Ferris at the University of Toronto. Boojum Research Ltd. developed a ground water model for the site to define the quantity of groundwater to be treated and field tested urea degradation.