ENFORCE29106 - Laserfiche WebLink

Home Browse Search

1 16) In the Spring and Summer of 1996, no "...BEM water was being pumped to the west side of the mine", as stated by the Division that "two different MCC personnel stated". Instead, Henry ' Barbe recalls that he stated that water was being pumped to the sealed sump (water from the Jumbo North Mains to 29 crosscut) and I recall that I stated that no water from the B East Mains fault inflow was being pumped to the sealed sump. Without clarifying the water source, it is understandable why these statements might appear to conflict or be confused. Phil Schmidt of MCC met with Beaz to inform them of MCC's plans as a precaution (MCC similarly cautioned a ' surface landowner to not occupy his cabin while MCC was mining the SNW panel beneath it, even though no damage or affect to safe occupancy was projected). MCC did not have the pipeline and pump system completed from the B East Mains area to the sealed sump until months ' later. As was reviewed and reiterated during the June 30th meeting, the sealed sump was not utilized to store large volumes (as opposed to the small volumes pumped from the Jumbo area) until November 1996. ' 17) Because of the high levels of suspended solids in the water in the NE Tailgate sump, this water was directed to the sealed sump. In MCC's January 27, 1997 letter, MCC had requested t CWQCD approval to bypass the sedimentation ponds and discharge into the spillways, assuming the water collected behind the bulkhead (hydraulic) seals partially constructed in the 14 SE Headgate entries (more than 1,000 feet outby from the fault inflow) would meet the necessary ' water quality standards. As discussed above, water that flowed on the mine floor or to the NE Tailgate sump had increased TSS levels. As the sealed sump had a limited volume, the cleaner water was pumped outside and discharged to the spillway if standards were met and the dirty ' water from the NE Tailgate sump was directed to the sealed sump, until it was filled in early March 1997. As MCC was working to save the mine, the pipelines were valved in several locations to provide as many options as possible for directing water, including to the sealed sumps ' and/or out of the mine. 18) The NE Tailgate sump was developed after the largest inflows had occurred from the fault in ' the fourth and fifth entries of the B East Mains in March and April 1996, but before development was begun again in the first, second and third entries. Prior to this time water was sumped in the ' initial gateroad entries (called "neck-ins") for the 10 NE and 11NE longwall panels. The slope sump was constructed near the base of the B-seam slopes at the time the slopes and in-mine ventilation raise was being constructed in 1991. ' 19) MCC had no reason to pump clean water directly from the fault inflows to the sealed sump, as this water could be discharged within discharge standards through MCC's surface systems with ' little or no treatment. As discussed above, due to the limited volume of the sealed sump, the higher TSS water from the NE Tailgate sump was the primary source. 20) During the large, 14 SE Headgate fault inflow event, the water flowed across the mine floor and accumulated in the Box Canyon main entries located down-dip. From there the water was pumped to the large NE Tailgate sump and then was pumped through one or two booster pump ' stations set up at 14, 15 and 16 crosscuts in the B East Mains, and then was directed in a series of 6" pipelines to the sealed sump and/or out of the mine to the sedimentation ponds. As the flow rates diminished, MCC was able to direct these flows to the NE Tailgate sump, rather than allow ' continued flooding of the Box Canyon Mains. MCC found though that water that flowed on the