ENFORCE29106 - Laserfiche WebLink

Home Browse Search

' 4 t rate is defined to be perhaps less than the lowest seepage rate calculated in TR 80 per MCC's actual experiences; i.e. there were dry coal faces immediately prior to the high pressure fault inflows, and, most importantly, after drilling the NW Sump #1 horizontal drill hole 215 feet, the ' first water was encountered just 17 feet from the filled sump. No other data, including geologic mapping, permeability measurements, inflow monitoring or other data were obtained and/or provided by Bear -only an observation of a wet or seepy rib in Third West (indicative of a ' dispersed flow, rather than a specific flow from a fracture, fault or other secondary porosity). MCC's records of mining conditions in both the Bear Mine and West Elk Mine did not show any ' fractures or faults in the unmined barrier between the mines. These records did indicate that there were at least two fractures with water encountered (but not reported) by Bear in nearby development in the Bear Mine. ' 9 - 12) See the above discussions and responses #5 and #6, above. ' 13 - 14) Flow meters had not been installed on the pipes when the large volumes of water had to be pumped to the sealed sump during the large fault inflow event in early 1997. The sump was determined to be full in early March 1997, when water was observed seeping from around the ' seals in the 1NW tailgate at 14 crosscut. MCC continued to observe a relatively constant level of water at those ventilation seals until new seals were built up-dip in 12 crosscut. Additional water was pumped to the sealed sump to bring the water level to the elevation of the northern-most ' 7NW seal (also called the Lone Pine seals) at the northwest side of the sump, so that water would reach the elevation of that seal and the dewatering pipe installed through the seal. Then, to get water to flow from the sealed sump through the pipe to sample, more water was pumped to the ' sump, similar to adding water behind a dam to raise the water level to flow over the spillway. Since the connection of the in-mine pumps and pipeline was completed from outside the Lone Pine seal to the Lone Pine Gulch pipeline in late December 1997, water has been regularly ' pumped to and discharged out of the sealed sump to Lone Pine Gulch. 15) See the above discussions and responses #5 and #6, above. ' Fault Water Routine - ' As discussed during previous meetings (and summarized in the attached memoranda), the temperature of the water in the sealed sump has been measured at 74 ° F and the fault inflows ' were about 84 ° F and 89 ° F from the B East Mains and 14 SE Headgate faults, respectively. This ten degree (or more) drop in temperature was documented in water being pumped out of the mine, as well. Whether the water was pumped from the NE Tailgate sump or directly from the ' bulkhead seals in the SE Headgate, the water became cooler as it was circulated through the pipelines. ' MCC has found evidence of continued spontaneous combustion in the C-seam of the Bear Mine. MSHA inspectors interviewed by MCC, stated that Bear had historic carbon monoxide problems with their mine ventilation. Carbon monoxide, a product of coal combustion, would occasionally ' move through (or "in-gas") from behind the C-seam seals in the Bear Mine that bracketed the entire length of their main entries from the portals to the B seam access slopes. MCC believes that spontaneous combustion is a very plausible and the most likely source of heat for the ' Edwards Mine discharge.