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material removed from the site and water for dust control. In order to enable dry mining, dewatering trenches will be constructed azound the perimeter of the pit. The collected water will be routed and pumped back to the South Platte River. The total exposed groundwater associated with the dewatering trenches is estimated at 1.0 acre. The NOAA Technical Report NWS 33, Evaporation Atlas for the Conti¢uous 48 States (U.S. Department of Commerce) was used to determine gross evaporation. For this location, the annual evaporation is 42 inches. Monthly evaporation percentages as suggested by the Office of the State Engineer were used to calculate monthly evaporation. Precipitation was estimated from the High Plains Regional Climate Center for the Northglenn Weather Station. Annual Precipitation at the site was assumed to be equal to the Northglenn Station, which is 14.08 inches. Effective precipitation was calculated as 70% of the total precipitation. Net evaporation was then computed as the difference between gross evaporation and effective precipitation. The net annual evaporation at the site is 2.70 feet. Thus, the resulting net annual evaporative consumptive use during the mining operation is 2.70 acre-feet. (d) Estimate project water requirements including jlow rates and annual volumes for the development, mining and reclamation phases of the project. Following mining, the material will be conveyed under 104`h Avenue to be processed at the plant serving the Cooley Reservoir and Fulton Wildlife Area -File #M-99-034. The water retained in this material is considered as a consumptive use. The anticipated amount of material that will be mined and washed from the site each year is estimated at 2,000,000 tons of raw material. Assuming 4 percent moisture content by weight as suggested by the State Engineer's Office, the total annual depletion due to water retained in product is 58.9 acre- feet. In addition, water use at the site will include dust control. From previous experience, in mining operations similaz to this one, a reasonable estimation of 2.0 acre-feet per yeaz was used in determining the total consumptive use of the mining operation. The total annual consumptive uses associated with the mining operations are as follows: Eva oration acre-feet 2.70 Moisture Retained in Product (acre-feet) 58.90 Dust Control acre-feet 2.00 Total (acre-feet) 63.60 Please refer to the attached temporary substitute (water) supply plan (TSSP), prepared by Applegate Group, Inc., and submitted to the Office of the State Engineer for more information. (e) Indicate the projected amounts of the water sources to supply project water requirements Replacement water will be provided under Aggregate's South Platte Combined Replacement Plan which has been accepted and approved by the State Engineer's Office. Sources of water AGGREGATE INDUSTRIES - HAZELTINE MINE MLRB I l2 PERMIT