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The water in the underburden is characterized as a hard, moderately alkaline <br />saline water with high sulfate concentrations (average sulfate concentrations <br />of 695 mg/1 ). Two wells show a calcium/magnesium sulfate type water while one <br />well shows an alkaline sodium bicarbonate type water. The TDS varies from <br />960-2648 mg/1, averaging 1619 mg/1. Dissolved iron levels vary from 0.02 to <br />2.51 mg/1 and average 0.63 mg/1. The sodium bicarbonate well occasionally <br />exhibits pH levels which exceed the recommended agricultural standard. <br />Another well shows manganese levels which exceed the agricultural standards. <br />All wells meet the recommended water quality standards for livestock <br />watering. The underburden aquifer does not produce acceptable water for <br />domestic purposes; TDS, sulfate and ammonia standards are exceeded. <br />Ground water within 150' of the ground surface has been only minimally <br />developed for use in the Nucla area. High salinities and occasionally high <br />sodium or sulfate concentrations preclude its use as domestic, agricultural or <br />stock water. In addition, moderate hydraulic conductivities are coupled with <br />low sustained well yields (less than 1.5 gpm), discouraging sustained <br />dependence on wells completed within these aquifers. <br />Soils <br />There are two primary soil series present on undisturbed sites within the <br />present Nucla Mine permit area (see Tab 9 of the permit application). The <br />major soil is the Shavano series. It is a fine, loamy, mixed, frigid (ustic) <br />Camborthid. Topsoil quality is good to an average depth of eighteen inches on <br />the gentler slopes and twelve inches on the steeper slopes. <br />The Persayo series is found in conjunction with the Shavano soils on isolated <br />ridges and steeper slopes in the permit area. The surface soils may range in <br />texture from sandy clay loam to clay loam with variable content of shale and <br />sandstone fragments. These steeply sloping, shallow soils are less suitable <br />for topsoil than the Shavano series described previously. An average of six <br />inches of fair topsoil may be obtained from the Persayo Series. <br />There are three major soils types at the proposed Nucla East area (see Tab 9 <br />of the permit revision application): Progresso-Bond Complex, 2 to 15 percent <br />slopes; Barx sandy loam, 1 to 4 percent slopes; Haplaquolls, 1 to 3 percent <br />slopes. <br />The Progresso-Bond complex is comprised of 40 percent Progresso, 40 percent <br />Bond, 10 percent Barx (see below), 5 percent Travesilla, and 5 percent Bowdish <br />series soils. The Progresso series is classified as a fine-loamy, mixed, <br />me sic, Ustollic Haplargid. The Bond series is a loamy, mixed, mesic Lithic <br />Ustollic Haplargid. The main difference between these two is the distance to <br />bedrock; Bond soils are shallow (17 to 19 inches to bedrock) while Progresso <br />soils are fairly deep (36 inches to bedrock). This complex is found on gently <br />to strongly sloping irrigated uplands over much of the Nucla East area. The <br />soils are shallow to moderately deep, well drained sandy loams formed in <br />sandstone derived alluvium. Topsoil quality is good to an average depth of <br />2.1 feet. <br />-12- <br />