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 surface represented by water level measurements in the Trout <br />Creek Sandstone 5 Mine well (Fig. 3), has recovered to the levels measured in 1986 <br />through 1988. This recovery is apparently from a reduction in pumping for use by the <br />mining operation. The well is used for water supply as well as monitoring. Historical <br />water level fluctuations of 20 to 200 feet have been observed at this well but no <br />seasonal pattern is evident. An additional Trout Creek Well, the Okie Plaza well was <br />abandoned in June 1994 as mining advanced through its location. See the 1994 <br />Annual Hydrology Report for data on this well. <br />The water levels in the Middle Sandstone formation as measured in wells TRH, TR-7a, <br />81-01, 83-01, 83-02, and 83-03 show fluctuations which are apparently related to <br />dewatering and subsidence associated with Mines 5 and 6. Wells TRH, TR-7a, and <br />81-01 displayed unusually large fluctuations during 1998. The declines in the levels in <br />C-81-044 7998 AHR Page 2 <br />