Acid drainage from the South Dump of Mine Doyon in Quebec was first noted in 1985,
and levels of contaminants continued to increase through 1988. Although the South
Dump does not have a high sulphide content (3-5%) it is estimated that 50% of the
waste rock dump is composed of highly reactive sericitic schists. An exhaustive
monitoring program was initiated in the summer of 1990, and has included analysis of
leachate coming from below and around the dump. The chemical data generated are
described in the report.

The report is a compilation of all chemical and mineralogical data from the South Dump
of Mine Doyon which have been gathered and analyzed to date. The data is organized
in five sections: chemical analyses of sampled leachate; a discussion of water quality
in the unsaturated zone; mass balance calculations based on chemical data; chemical
composition calculations based on common physical parameters; and data obtained
prior to 1991. The parameters measured and discussed herein include: flow
measurements; total dissolved solids; effluent density; conductivity; pH; acidity;
sulphate; iron; and a wide range of associated metals.