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n Based upon the observed flows in the two mines, it appears that the <br />• majori*_y of the inflow is coming from dewatering of the coal beds. <br />Additional flaws are coming from fault zones, and to a lesser extent from <br />pillared areas of the mines. Because water level declines are being i <br />observed in the aquifers overlying (and unaerlying) the mines, it can be <br />' assumed that some of the inflow to the mines is from these aquifers. <br />However, it is not possible to determine whether the sandstone aquifer <br />water is reaching the mine through faults or through general seepace <br />through the- mine top and/or bottom. <br />The water qua 1 i ty data for the fau 1 t zone i nfl ow i n the No. 5 mine <br />(Table III-18) indicates that the water is of virtually identical <br />' chemistry to the rest of the mine inflow. Therefore, it is unlikely that <br />the source of inflow is directly from sources other than bedrock units, <br />which exhibits markedly different chemistry from the mine inflow water. <br />3.4.7.2 Predicted Inflows <br />Ground water inflow analyses were performed on both the Na. 5 and No. <br />9 mine inflows. An additional analysis was also performed on the 2 West <br />Main inflow in the No. 5 Mine. The projected mine inflows were made <br />assuming an aggressive mining sequence in both mines with completion of <br />all mains in the No. 5 mine in 1984 and completion of all mains in the No. <br />9 mine by 1988. Less aggressive mining sequences would produce smaller <br />maximum inflows for the mines. <br /> Three types of analysis were performed to estimate future mine <br />y~ inflows: (1) Theim' s (1906) steady state well formula, (2) Jacob & <br />III-70 <br />