Laserfiche WebLink
2.04.7 Hydrology Description <br />Lower Perched Water Zone and Rollins Sandstone <br />A sufficient number of data points were obtained from the drill holes to plot <br />potentiometric surfaces. As seen on Maps 10A, 10B and 11, the <br />potentiometric contours generally fit the geohydrological setting of the permit <br />area in that the saturated horizons (or potentiometric surface) gently dip <br />northward, following the structural attitude of the bedrock horizons. East of <br />Terror Creek the lower perched water bearing zone is more continuous than <br />the upper perched water bearing zone. Map 11 projects the piezometric <br />surface of the lower perched water bearing zone in the northeastern portion <br />of the permit area. Map 11 -1 is a fence diagram showing the lower perched <br />water bearing zone in relation to monitoring wells and the underling B -Seam. <br />The lower perched water bearing zone contours were not projected into the <br />west mining area since the geohydrologic setting changes west of Terror <br />Creek and most of the projected contours would be located north of the <br />western mining area. Map 10A presents the regional projection of the <br />potentiometric surface above the B -Seam. <br />The Rollins Sandstone in the permit and adjacent area is characterized as <br />dry along the outcrop and develops piezometric head as the formation dips <br />to the north. Monitoring well DH -34B, NM4 -98 -29 and TC -03 -01(R) are <br />completed in the Rollins Sandstone. The water level in all three wells is <br />under artesian conditions ranging from 200 to 475 feet. Monitoring well <br />NM4 -98 -29 was located underground in the Bowie No. 2 Mine, D -Seam north <br />mains. Oxbow has two wells completed in the Rollins Sandstone (SC -1 & <br />SC -2) and they are also reported to be under artesian conditions (SMC <br />permit section 2.04.7). Mountain Coal Company has one well completed in <br />the Rollins Sandstone (SOM- 128 -H) which is also under artesian conditions <br />(MCC 1994 AHR). The quality of the water in the Rollins Sandstone is poor <br />with the Bowie No. 2 Mine wells exhibiting better quality than adjacent mines. <br />The following table presents typical values for selected chemical parameters <br />from the water in the Rollins Sandstone from the three mines referenced <br />above: <br />PR-14 2.04-41- 03114 <br />