GENERAL52490 - Laserfiche WebLink

Home Browse Search

The Quaternary terrace deposits aze at best limited aquifers. These deposits have a coazse gravel-boulder layer at their base that tends to drain the deposits to the side slopes of the Animas River Valley. The terrace deposits do not supply subirrigation to crops. These terrace deposits aze currently used regionally for dry land wheat farming. The alluvium of the Animas River is a regional aquifer located 400 feet below the main mining operation. The alluvium is poorly sorted and coarse with ground water levels coincident with the river. The alluvial body thins and becomes narrow at the point where the Animas River cuts through the Pictured Cliffs Sandstone and Fmitland Formation. Surface Water Hydrology The Carbon Junction Mine is located within the Animas River Drainage Basin. The mine is located within the valley of the upper reach of Carbon Junction Canyon. The stream which drains the site is intermittant and has a steep gradient and a deeply incised channel. Stream flow in Cazbon Junction Canyon is directly tributary to the Animas River to the southwest. The drainage basin of Cazbon Junction Canyon is 0.8 squaze miles. The stream flows along the contact of the Pictured Cliffs Sandstone and the Fruitland Formation. This stream rechazges these strata upgradient and receives dischazges from these strata in the form of seeps and springs down gradient. The flows in Ute stream fluctuate seasonally and in response to thunderstorm events. Highest flows occur during snowmelt and during eazly summer when precipitation events aze more frequent. Some baseflow to the stream is provided by springs in the stream channel. Spring and seeps, however, do not provide enough flow to sustain stream flow from mid summer and early fall when evaporation and transpiration aze high. The water in the stream of Cazbon Junction Canyon is not diverted for flood or subirrigation of crops. Any use of water derived from Cazbon Junction Canyon would be through diversion of Animas River water downstream of the confluence of these two streams. The water quality of the stream in Carbon Junction Canyon fluctuates seasonally. The water quality in the stream is generally better during periods of high flow and gradually decreases in quality as spring flows become more dominant. The quantity of water from Carbon Junction Canyon tributary to the Animas River would be insignificant to the overall flow of the river. The drainage basin of Cazbon Junction Canyon is only 0.8 square miles compazed to over 1090 squaze miles for khe Animas River above the Colorado-New Mexico state line. The applicant has installed and will monitor two surface water stations upstream and downstream of the proposed mine. Both stream flows and water quality samples are collected at these sites. Surface water discharges from sediment ponds are monitored under NPDES requirements and copies of monitoring reports will be submitted to the Division quarterly. The surface water monitoring plan is adequate to monitor the effects of mining on the hydrologic balance. Climate The climate of the area is relatively moderate, with a monthly low mean temperature of 25.3°F in January and a monthly high mean temperature of 67.0°F in July. Record temperature extremes range from a high of 99°F,