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March 2003 Energy Fu<4 Coallnt. - Southfield Mine * 2002 Anxual Hydrology Report ~ Page 8 <br />3.0 GROUND WATER AND SURFACE WATER <br />MONITORING RESULTS <br />3.1 GROUND WATER MONITORING RESULTS <br />Mine Area <br />In the Mine Area, ground water occurs in surficia] alluvialJcolluvial deposits and under water table <br />conditions in the sequence of sedimentary rocks corresponding to the Vermejo, Raton, and Poison <br />Creek formations. Due to semi-arid conditions and the limited extent and continuity of the <br />alluvial/colluvial deposits, these units do not store or transmit appreciable quantities of ground water <br />in the general mine azea. Variable lithology and significant cross-bedding and inter-bedding within <br />the bedrock geologic units results in limited lateral or regional continuity of potential water-bearing <br />units. As a result, there are no known aquifer units and bedrock groundwater occurrences are limited <br />ro isolated units and zones that have sufficient local rechazge and permeability to store and transmit <br />water. In most cases, this translates into isolated perched ground water occurrences and water <br />storage in abandoned and flooded mine workings, which serve as collection and storage reservoirs for <br />minor ground water and fracture flows (refer to Section 2.04.7 of the Southfield Mining and <br />Reclamation Plan document for more details). <br />In the Mine Area, the current ground water monitoring program includes the following monitoring <br />wells, located as shown on Figures 1 and 2, Mfne and LoadoutMonitorrng Stationr. <br />Well Location <br />Depth/Com~etion <br />MW-10 E'1: NE'/< Section 25, T20S, R69W 402'(342-402' <br />MW-16 E'hNW'/. Section 3Q T205, R69W 136'/106-136' <br />MW-23 E'hSW'/+ Section 19, T20S, R69W 179'/149-179' <br />MW-65 W'/~SW'/. Section 24, T20S, R70W 1,448'/968-988' <br />Completion Zone <br />Jack O'Lantem Coal Seam <br />Jack O'Lantem Coal Seam <br />Red Arrow Coal Seam <br />Jack O'Lantern Coal Seam <br />Monitoring wells MW-7A, MW-7B, MW-10, and MW-22 were previously included in the monitoring <br />program, but have since been mined-through and eliminated from ongoing monitoring. Well MW-8 <br />was mined-through in 1993 and immediately went dry. Subsequent monitoring showed that the <br />borehole had collapsed to a point 336 feet below the surface. The water level recovered and gradually <br />increased from the 280 foot level beginning in early 1996. Measured water levels in this well indicated <br />that sub-surface conditions above the point of collapse had stabilized. In the final quarter of 1999, <br />however, ongoing monitoring indicated that the well had again collapsed at approximately 250 feet <br />below ground surface, making further water level measurements impractical. Field and laboratory <br />analysis data for active monitoring wells are summarized in the following discussions. Raw field and <br />laboratory data for the 2002 water year are provided for reference in Appendices A and B. <br />Measured water levels for all Mine Area monitoring wells are summarized in Table 4, Monitor Well <br />Water Levek, and historic water level data aze graphically depicted for the five monitoring wells <br />(includes historical information for Wells MW-8 and M\X/-10) by Figures 3, 4, 5, 6, and 7, Water Levels <br />for We11 MW-XX. Review of historic water level data shows that wells MW-8 and MW-10 caved in <br />late 2000 and have remained dry since. <br />MWH * 1475 Pin< Grove Road, Suite 109 * Steamboat Spring; CO 80487 * (970f 8796260 <br />irwv/[.y rarmuz,a.w ryr~W <br />rlre/ar.x~ <br />