A geochemical survey was performed on the Equity Silver Tailings Pond near Houston,
B.C. in the fall of 1995. Replicate peepers were used to collect pore waters from each
of a shallow (~1 m) and deep site (~5 m) within the tailings pond. Ancillary solid-phase
and water column data were also collected.

The distributions of most elements is indicative of small-scale, lateral inhomogeneity.
While dissolved Cu is neither released nor consumed by the tailings, Sb and As display
opposing fluxes. Arsenic is released from pore waters to pond waters at both sites in
all replicates via dissolution of an unidentified solid phase. Conversely, Sb is
consumed rapidly within the surfical deposits, presumably by adsorption to an existing
solid-phase.

Direct determinations of tailings oxidation rates were calculated by measurements of
dissolved oxygen from the peepers cells across the sediment-water interface.
Dissolved oxygen fluxes were determined by the application of Fick’s law of diffusion
across the interface and also through a diffusion-consumption model applied to the
dissolved oxygen data in the pore waters. The tailings oxidation rate (assuming the
entire oxygen flux was consumed by tailings oxidation) was within the range of values
seen for other subaqueous tailings deposits.