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<br /> <br />Lafarge North America -Stagecoach Stop Sand and Gravel Mine <br />Groundwater Monitoring Program <br />The following groundwater monitoring program is proposed for the Stagecoach Stop <br />Sand and Gravel Mine and is being provided in conjunction with Exhibit G of the DMG- <br />112 Permit Application. The monitoring program proposed herein will analyze <br />fluctuations in the underlying water table that may be caused by mining operations. The <br />focus of the program will be to compare historical water levels to those experienced <br />during future mining activities. This analysis will assist Lafarge North America (Lafarge) <br />in mitigating possible losses in nearby wells and water storage. The following <br />monitoring program discusses: 1) the installation of six piezometers (monitor wells); 2) <br />frequency of monitoring; 3) duration of monitoring; 4) provisions of baseline monitoring; <br />5) results of data reporting; 6) DMG notification criteria; and 7) mitigation possibilities for <br />drops in water levels. <br />1) Four piezometers have already been installed along the east side of the property <br />(see enclosed map) to a depth of approximately twenty-feet below the surface. <br />The welts were drilled by an experienced drilling crew using a CME 75 drill rig. <br />Each well has been constructed outside the location of the proposed slurry wall <br />with one 10'-2" screen section and one 10' section of 2"- PVC riser casing. Well <br />protection utilized sand pack, bentonite seal, concrete pads, and steel lockable <br />casings. The casings are approximately 3' above ground level. Since the time of <br />the installation of these four monitoring wells, Lafarge has begun monitoring two <br />additional existing wells located on neighboring properties, and has committed to <br />drilling two additional monitoring wells (see attached map) to increase the <br />amount of baseline data available. The additional piezometers that will be drilled <br />will follow the same design criteria as stated above. <br />Locations for the data collection were established to provide information on <br />possible impacts up gradient of the site and along the eastern mining boundary. <br />Due to the possibility of exaggerated water levels along the river, data will not be <br />collected along the western boundary. <br />2) Monitoring data will be collected from all piezometers at least on a quarterly <br />basis. Monitoring may occur more frequently if dictated by conditions. <br />3) The duration for the monitoring program will cover a reasonable period of time <br />prior to mining and will continue concurrently with mining. Monitoring will last for <br />the life of the mine. <br />4) Historic data collected through this monitoring program will determine baseline <br />averages for the area prior to any disturbances below groundwater. This data <br />will be compared with data collected during mining activities to help assess any <br />impacts the mine may be having on local hydrologic conditions. Hydrographs will <br />