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• ground water system. With a consumptive use rate of ten percent, the annual consumptive use of water by the <br />domestic facilities is 0.2 acre-feet. Since there is no outside irrigation and the work force does not fluctuate <br />seasonally, this rate of consumptive use remains constant throughout the year. It should be noted since <br />domestic water will likely be hauled from outside of the Chandler Creek Basin; a credit against consumptive <br />water use of the total mining operation can be taken for the flows returned to the stream system from the <br />imported water. <br />Dust Suppression Inside Mine <br />Water is required for dust suppression inside the mine. The amount of water used for inside dust suppression <br />can be estimated by analyzing the water uses associated with a similar, nearby mine operation and analyzing <br />laboratory moisture analyses. Based on this review, approximately 3.7 acre-feet is estimated to be diverted into <br />the mine for dust suppression purposes. Dust suppression water also includes moisture naturally contained <br />within the coals and mine seepage. The consumptive use of the water used for inside dust suppression is <br />different than the total amounts of water used, because some of the water remains on the raw coal and is <br />transported out of the mine. <br />• Results of laboratory analysis for other similar mines show that 9.58 percent by dry weight of whole core <br />samples is the moisture retained after draining by gravity, or specific retention. This is equal to 8.33 percent by <br />wet weight of the raw coal leaving the mine. The difference in the raw coal between total moisture (15.0 <br />percent by wet weight of raw coal) and specific retention (8.33 percent by wet weight of raw coal) is, therefore, <br />consumptive use (6.67 percent by weight of raw coal). At the projected rate of production of raw coal leaving <br />the mine, this is equal to an annual consumptive use rate of 20.85 acre-feet. This consumptive use rate may <br />increase proportionally with increased coal production to the maximum of 20.85 acre-feet per year at peak <br />production of 425,000 tons per year. <br />Dust Suppression Outside Mine <br />According to a review of other similar mine operations, average work-day water requirements for outside dust <br />suppression are projected to be 5,000 gallons. Outside dust suppression watering is conducted for 8 months of <br />the year, or about 160 working days assuming a 5-day work week. Annual water requirements are estimated to <br />• -18- <br />