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Table M87-1 contains the results of the mine inflows study of the Cameo Mine <br />on October 6, -1987. As noted in the surface water section pumping to the surface <br />• was discontinued in October 1986. For the remainder of the water year, the mine <br />inflows were pumped or directed into the No. 1 East Mains seals. The 1987 Mine <br />Inflows map shows the estimated water level behind the seals. The average mine <br />inflows for the first 10 months of the calendar year 1986 was 63 gpm. This inflows <br />study showed 63.9 gpm. The assumptions made in the 1986 Annual Hydrologic Report <br />concerning the mayor sources of water in the Cameo Mine were wrong. This year's <br />study showed two-thirds of the water coming from the portal area underdrains <br />with the balance coming from the floor, roof and ribs in the mine. The mass <br />average pH for these inflows was 8.8 and the mass coverage conductivity was 2150 <br />Iamhos/cm. <br />Table M87-2 contains the results of the mine inflows study of the Roadside Mine. <br />Pumping from the B sump was discontinued in October 1986 and pumping from the <br />East Mains sump was discontinued in December 1986. For the remainder of the <br />year, inflows were directed into abandoned portions of the mine with no pumping <br />being necessary. The additional monitoring locations this year were not new <br />inflows but a more detailed study of existing flows. A portable HS-flume was <br />used to take the flow readings this year. These flows are believed to be more <br />accurate than flows taken in the past with buckets or floating sticks and a stop <br />watch. The measured flows were considerably smaller in 1987 than in 1986 for <br />most of the locations monitored. The decrease in flows at locations 5 and 6 <br />were primarily due to the lack of mining activity. The lower flow at location <br />Z may be associated with the lower flow in the Colorado River. The reason for <br />higher flow of location 3 is unknown. The mass average pH for the total measured <br />flow of 155.9 gpm was 7.7 and the mass average conductivity was 1115 Nmhos/cm. <br />• The water quality was generally poorer where potentially exposed to roof rock <br />such a5 location 2 and sealed areas 3, 7, 8, 9, 11 and 12. These areas had a <br />mass average conductivity of 1730 umhos/cm compared to a mass average of 740 <br />for the remaining inflows. The estimated water level in the abandoned area of <br />the mine is shown on the 1987 Mine Inflows Map. This estimate was made using <br />the average of the 10/86 inflow and the il/87 inflow plus 41.5 gpm for location <br />1 behind the seal. <br />CONSUMPTIYE USE <br />During the 1987 water year, water was consumed in the mining process, in the <br />coal preparation plant and in the surface facilities. Table C87-1 has been <br />prepared to show the water consumed in the preparation plant and the domestic <br />water purchased. (Table C87-1 includes information from the last quarter of <br />the 1986 Annual Hydrologic Report.) <br />The last day of active mining was October 3, 1986 which eliminated mining process <br />usage. The preparation plant continued for another two weeks to finish stockpiled <br />coal at which time coal preparation usage stopped. The employment dropped from <br />210 October 1, 1986 to 11 on January 1, 1987 which reduced the surface facilities <br />usage. Apparently the domestic water billing period begins near the end of the <br />month because the preparation plant usage for the first half of October 1986 <br />did not show up on the October 1986 billing for Meter 2. Several leaks were <br />detected in 1987 which accounted for part of the domestic usage. The following <br />. is a summary of consumptive usage for the 1987 water year. <br />-4- <br />