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That is, there nearly always seems to be some residual error, some excess concentration or not enough of some element to totally explain the geochemistry. In the present case, there appears to be a relatively straightforward solution that closely relates the general geochemistry of the fault waters to the seep water. Moreover, there seems to be an even closer geochemical similarity between the Edwards Portal seep water and the Lone Pine Seal water. Even further, the Lone Pine seal water lies more or less on a trajectory, in Piper diagram space, between the fault waters and the seep water, with very minor deviation being explained by higher Na and K in the Lone Pine Seal and higher sulfate in the seep. Together, these suggest that the Lone Pine seal waters describe an intermediate composition between the faults and the seep, with minor deviations to be explained. The following sections describe a plausible interpretation of the data for the West Elk situation. Maintenance of High Temperature at the Seep. Since the seep was first monitored, temperature has fluctuated very little. Division records indicate variations on the order of tenths of a degree to a few degrees since November 1997. Thus, because the temperature has remained relatively constant, and high, there must be a constant supply of heat to the seep water source. If [he fault waters reach the seep via seepage though the coal wall, down-dip of the sump, then the sump water itself must be the source of the thermal mass. Without a heat source at that point, the seep water could not have maintained the treasured high temperatures. West Elk Mines maintains that the seep water heat comes from thermal waters beneath or close to the seep. An alternative simple explanation seems possible. When warm fault waters (at least 85 to 95 degrees F, and possibly higher) were encountered, they were conveyed to the NW Panels sealed sump. As the sump eventually filled. water was discharged to the North Fork Gunnison River via the Lone Pine Gulch pipeline. Because warm incoming water is eventually discharged via the Lone Pine Gulch pipeline, a relatively high temperature has been maintained in the sump. Thus, a relatively constant, high temperature has been maintained in the seep. Major Element Chemistry and pH. The geochemical composition of the fault waters does not match that of the seep. West Elk Mine maintains that this is evidence that the two waters come from different sources, through different fractures. Waters in the Rollins Sandstone are targeted as a possible source. However, the Rollins Sandstone water is likewise of a composition different from the seep. While [his does not dismiss the Rollins as the direct source of the seep water, it does require an explanation of how the Rollins water evolved into the seep water. That path is at least as complicated as a path from the fault waters to the seep water. a feasible model for evolution of the seep water from [he fault water via interaction with certain minerals and meteoric water can be developed. 4