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• -11 • bicarbonate as the dominant soluble ions. Chemical analyses for these wells further show that concentrations of iron, manganese, ammonia, total dissolved solids, hardness, sulfate, and pH may exceed drinking water standards. Trace element concentrations are below detection limits in many samples. These waters are marginally suitable for domestic use, and are adequate for livestock watering. Most groundwater in the general area will present a medium to high salinity hazard for crops according to the U.s. Department of Agriculture Classification for Irrigation Water (USDA, 1969). Occasionally, high-sodium-hazard groundwater may be encountered locally. With the exception of a single high boron value, the concen- trations for all other constituents are below the standards set forth far agricultural use. Low well yields, steep hillsides, and poor water quality throughout the region generally limit developing aquifers for agricultural use. It can be concluded that groundwater quantity and quality in the general and adjacent area is variable and, to a certain degree, unpredictable as a source for beneficial use. GROUND WATER MONITORING The applicant plans to continue its groundwater monitoring program to identify any impacts that mining operations may have had on the hydrologic balance. All moni- toring sites are located in areas which identify pre-mining and post-mining water quality and quantity and will, therefore, be able to detect problems associ- ated with mine hydrology. There are 46 monitoring wells located in the permit area and adjacent areas. !/ater levels are measured monthly and water quality samples are taken in accordance with CMLRD. The applicant proposes to replace any observation wells destroyed during the course of mining with ~veZls completed in spoil materials to monitor water quantity and quality. WATER RIGHTS Present uses of groundwater in the region are Limited to domestic and stock watering supply. Estimated groundwater usage in the upper Colorado Basin indicates that surface water is the main source of water. There are three registered groundwater rights within the area adjacent to the Seneca II mine. Two of these rights lie directly North of the mine permit area. The other right is the Seneca II shop well. The two wells North of the property are completed in younger strata some distance from the mining operation and away from the affected area of mining. The shop well is completed in the Trout Creek sandstone which is stratigraphically below the lowest coal to be mined. Studies performed by the applicant do not indicate that this well is adversely affected by mining. There are no known uses of water for irrigation within a one-mile radius of the area. with the acceptance of the stipulation requiring pump test analysis, the groundwater section is in compliance with Rules 2.09.5, 2.04.7, 2.05.3(4), 2.05.6(3) and 4.05.