Laserfiche WebLink
<br />GROUNDWATER MONITORING <br />BEDROCK <br />Three sandstone aquifers are monitored at the site. They are, in ascending order: <br />Trout Creek Sandstone (1 well), Middle Sandstone (6 wells), and Twentymile <br />Sandstone (3 wells). The #5 and #6 Mines are between the Trout Creek Sandstone <br />and the Middle Sandstone. <br />WATER LEVELS <br />The potentiometric levels, represented by water levels in Trout Creek Sandstone well <br />(Fig. 3), recovered to the levels measured in 1986 through 1988. This recovery is <br />• apparently from reduction in pumping for use since the well is used for water supply <br />as well as monitoring. Historical water level fluctuations of 20 to 200 feet have been <br />observed but no seasonal pattern is evident or expected. An additional Trout Creek <br />Well, the Okie Plaza well was abandoned in June 1994 as mining advanced through <br />its location. See the 1994 Annual Hydrology Report for data on this well. <br />The water levels in the Middle Sandstone (Figs. 4 to 9) show fluctuations which are <br />apparently related to dewatering and subsidence associated with Mines 5 and 6. The <br />declines in the levels in Wells 81-01 and 83-01 between 1988 and 1990 appear to <br />have leveled off since the middle of 1990, and have recovered to initially monitored <br /> <br />C•81-044 1995 AHR Page 2 <br />