Laserfiche WebLink
LORENCITO CANYON MINE <br />' ANNUAL HYDROLOGIC MONITORING REPORT - 2002 <br />,__.___ __ _~:.~ __ ~ _-~_~. . _ .~y.__ ~. -- .,._ <br />--- _._.__z~.___ ____._._ _..__.._ __.~____~ <br />SECTION 1 -INTRODUCTION <br />' To fulfill the requirements of the Regulations of the Colorado Mined Land Reclamation Board, <br />the following report has been assembled in compliance with Rule 2.04.7. Since the beginning <br />of 1996, substantial work has been performed at the Lorencito Canyon Mine site to interpret <br />' the hydrology of the area. Specific methodologies employed for this work are described <br />below. Field work accomplished during the baseline period has included the installation and <br />testing of 12 alluvial wells, 16 consolidated aquifer wells, along with the monitoring of 11 <br />' surface water sites, 11 springs and seeps, and 19 pond sites in the area. From the field data <br />collected, insight has been gained into the recharge and discharge characteristics of aquifers, <br />hydraulic properties, potentiometric and water table surfaces, and water quality for each of the <br />t hydrologic units. The program was reduced following issuance of the permit in August 1997, <br />resulting in a reduction of monitoring stations, frequency of monitoring, and water quality <br />parameter analyses. A revision to the program was also approved in early 1999 to reduce the <br />frequency of monitoring during the premine period until disturbance activities begin. <br />' In early 2001, a Permit Revision was submitted for approval of mining operations in the <br />surface mining area. As a result, the monitoring program was adjusted to use only those <br />stations that would detect potential impacts of these operations. These stations and water <br />quality parameters are listed on Tables 1-1 and 1-2. This revision eliminated all deep aquifer <br />wells from the monitoring program. This report presents the results of monitoring for <br />operations in 2002. <br />SECTION 2 -METHODOLOGY <br />Groundwater <br />To determine the presence of alluvial aquifers, wells were installed in the alluvium of major <br />canyons within the permit area. Four wells were installed in Lorencito Canyon, and two wells <br />in Cow Canyon, with the other canyons having one well installed near the canyon mouth. A <br />total of 12 wells were installed. Most wells were installed with ten feet of screen and <br />generally do not exceed thirty feet in depth. Alluvial wells were assigned names based upon <br />location. Each well was designated with an MW prefix, followed by a two or three letter code <br />for the canyon the well was located in, and a number to designate the location with the <br />numbers increasing up the canyon. The location of monitoring wells is depicted on Map <br />2.04.7-1. <br />AHR-00.4]5\March 10, 2003 1 <br />