Temporal variations in metal contents in selected waters of the South Bay Mine site : final report 1995.

Abstract

Boojum Research initially requested that simulations (using WATEQ and NETPATH) be applied to the analyses of July and August 1994 samples from various sources around the Mill site (WHS, BRC, PRC, PRS, MPO, BR13, C13), for comparison with the results of similar simulations applied to the analyses of July and August 1992 samples from the same sources. The prime objective of this exercise would have been to elucidate the effects of the various ditches constructed at the site. No simulations have been performed, however, because the analyses representing the July and August 1994 samples from these sources are incomplete, missing all major ions. Available analyses for samples collected from a number of selected points at the South Bay site, between October 1986 and September 1994, have been plotted to determine where heavy-metal concentrations are increasing or decreasing with time. In the graphs, the lines representing [Cu] and [Zn] are drawn heavy to make recognition easier. It has been assumed that the analyses are representative for the chemical composition of the various sources at the time of sample collection. If additional analyses exist for the locations represented by these graphs, incorporation of such analyses should probably be considered. It should be kept in mind that the detection limits for the heavy metals were apparently set at 1.0 or 0.1 mglL, rather than 0.01 mglL or lower, for some of the pre-1994 analyses. Thus some of the graphs may give the erroneous impression of very low metal concentrations during the early 1990’s.