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Mr. John Walters - page 4 • It seems that the major quantity of water inflow into the mine is related to the saturated part of the coal seam, and, in particular, in the zone near the fault where the coal is more fractured. The lower part of the Cameo coal seam seems to be more saturated. The east fault is water bearing only in certain parts. Due to a limited recharge capacity, only short term inflows into the mine along this fault were experienced. The recharge of the fault can be provided by the connection with the upper reaches of McClane Creek at two locations (see Figure 2) and from the upthrown section of the Cameo seam. The quality of the ground water in the mine is known from several samples collected in the mine or from the sedimentation pond during the period between June, 1962 and January, 1985. The water seeping into the mine is of bicarbonate, sulfate type with a relatively low concentration of total dissolved solids (1,526 - 3,260 mg/1), and a pH in the range of 8.2 - 8.95. These chemical characteristics would indicate a similarity to the surface water quality in the upper reaches of East Salt Creek. Water in the alluvial aquifer of East Salt Creek at the confluence with McClane Canyon and in East Salt Creek downstream of the site has a higher concentration of total dissolved solids, • a substantially higher amount of sulfides and generally lower pH. Therefore, the quality of water seeping into the mine indicates the source as surface stream and/or shallow aquifers from the upper reaches of McClane Creek. Unfortunately, no water quality data for the saturated part of the Cameo coal seam or the upper reaches of McClane Canyon are available for comparison. Probable Hydrologic Consequences The original interpretation of the McClane Canyon mine hydrogeology was based on direct observation on the ground surface and evaluation of the results of coal exploration drilling. Using data from electric resistivity logs, a map showing the approximate unsaturated and saturated zones of the ' Cameo coal seam was developed. Boreholes 7-21-1 and 7-15-3 located within the graben mined by the McClane mine did not indicate any water presence in the Cameo seam. Monitoring of the water inflow into the McClane mine indicated that the saturated zone of the Cameo coal seam is extended in the mined graben more to the southwest than originally believed. The original and new interpretations are presented on Figure 3. The absence of measurable water in the Cameo seam in borehole 7-15-3 could be explained by the relatively great distance of this borehole from the east fault and by the observation that the coal seam is more saturated in a more fractured zone along the fault. The quantity of water inflow into the mine was increasing 7 i98~