Abstract: Covers are widely used as a means of controlling pollutant generation from sulfidic waste piles. To date, there has been little data available to test the effectiveness of such covers. Monitoring of two waste rock dumps at Rum Jungle over more than fifteen years has provided the opportunity to assess cover effectiveness in the medium term. For the first 9 years the infiltration rate through the cover on Whites dump was less than the design figure of 5 per cent of rainfall. In subsequent years, however, the rate has increased to between 5 and 10 per cent. In the first six years the infiltration rate through the cover on Intermediate dump was also less than 5 per cent. Unfortunately, further measurements had to be abandoned due to equipment malfunction in this dump. Oxygen and temperature profiles measured below the cover have been used to estimate the overall oxidation rate in the two dumps. This is between 30 and 50 per cent of the oxidation rate prior to installation of the cover. The effect these results have on pollutant loads in drainage in the long term depends on the nature of the control mechanisms in the system. If pollutant concentrations in drainage are determined by secondary mineralisation within the dumps then pollutant loads in the long term will be essentially proportional to any further increase in the infiltration rate. If the pollutant loads in drainage are largely determined by the overall oxidation rates then we can expect the pollutant loads from the two dumps to increase in the long term to a level about one third to one half of that prior to rehabilitation. In this context, 'long term' means about 40 years after installation of the cover system. Given the implications this work has for the use of soil covers, the following additional studies should be undertaken: A measurement program to quantify the pollution loads from Intermediate and Whites waste rock dumps. A program of computation, backed by acquisition of mineralogical data on the wastes, to address the question of controls on concentration and load in effluent from the two dumps. A program to determine the reason for the deteriorating performance of the covers at Rum Jungle.

Abstract: The mining industry has made tremendous strides in the last 20 years in the prevention and control of acid mine drainage. However, there remain a number of circumstances where the long-term operation, care and maintenance of tailings management facilities will be required. The application of progressive environmental technologies and management systems is key to cost control and environmental liability management at these sites. Mine Waste Management Inc. currently operates Rio Algom Limited's five effluent treatment plants and seven waste management areas in the Elliot Lake, Ontario region using a Remote Plant Monitoring and Control Network (RPMCN). This system, based on Intellutions's “Fix 32” technology, enables the monitoring and control of these plants from a centralized location thus reducing labour costs while providing 24-hour surveillance. Scheduling, auditing and reporting of plant operating and environmental monitoring programs are integrated and controlled using the Envista (super TM) environmental information management system. Proper application of these technologies and management systems facilitates delivery of cost-effective environmental monitoring, and care and maintenance programs at these sites and provides tools to demonstrate compliance with all environmental performance criteria.