REV105815 - Laserfiche WebLink

Home Browse Search

L Technical Revision No. 80 ............................................................................................................ Page 3 September 22, 1997 2. A small amount (the actual amount is unknown, but is estimated to be less than ]0 acre-feet per year, based on an average 5 gpm run-off flow from the mining faces) of operational water and small, local inflows not from the B East Mains inflows) gravity flowed along the dip and accumulated in the sealed NW Panels area prior to November 1996. Please note that the significance of November 1996 is that this date was when MCC began to pump and store inflow water from the B East Mains inflow to the NW Panels sealed sump. This occurred on an emergency basis because the sedimentation ponds were full and frozen-over, and could not be effectively treated to allow discharge within effluent limitations due to the TSS problem as described in the TR application. Operational run-off water was generated during the mining process and from dust suppression and cooling of the longwall and continuous miner equipment. This water, as well as minor inflow water, flowed down-dip to "small capacity sumps" (see discussion on page 2.05-238), that were located in the lowest (elevation), accessible areas of the mining section (as typical), and then was pumped from these sumps to the main slope sump and out of the mine to the sedimentation ponds. Until May 1995, when the 1NW - SNW longwall panels were sealed (as required by MSHA), the northeast corners of the 4NW and SNW panels ("sumps" where approximately 100 gallons of water naturally accumulated) and the operational sump developed in the northeast corner (the most down-dip area) of the 1NW panel were typically pumped once a day with small air pumps, and routed out of the mine as described above. Due to the higher elevation of the 8NW longwall panel, operational water, as well as minor inflow water, from the development of this panel also naturally flowed down-dip along the Jumbo Main and B West Main entries to the NW panels. Again, due to the natural dip, water tended to accumulate in the northeast corners of the 1NW, 4NW and SNW longwall panels and was regularly pumped from the mine until the first five longwall panels were sealed (as described above). After the sealing of 1NW - SNW was complete (in May 1995), water continued to flow naturally down-dip to the northeast (and small inflows probably continued to occur within the sealed area), but then seeped through and at times accumulated against the northern- most seals between the SNW and 6NW longwall panels. As these seals were constructed to "seal" the mine air (as required by MSHA) and were not intended to be hydraulic seals, water did move through them, albeit at a very low rate due to the low head of these small accumulations. MSHA also required that these ventilation seals be maintained to serve their function of sealing air, so water could not be allowed to accumulate on the seals and possibly deteriorate them. As such, MCC had to occasionally pump operational water and natural inflow water that was accumulating there to the Jumbo Mains and B West Mains then to the sealed area where it was naturally destined. This comparatively insignificant amount of operational water was the only water that was pumped and stored in the sealed area np 'or to November 1996 (as stated in Item #1 on Page 2.05-244). The water within the