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mine. Quantities of mine inflows have decreased by nearly <br />50~ from the period of 1990 to early 1994. The mine has <br />recently experienced a significant inflow of water occurring <br />in the spring of 1994, when a 100,000 gpm flow rate was <br />observed. The mine is presently investigating the source of <br />the inflow and will continue to monitor the inflow in the <br />future. <br />B. Surface water Description <br />The permit area and proposed expansion are dissected by three <br />major drainages: Newlin Creek (a perennial stream), Magpie <br />Creek and Second Alkali Creek (both of which are ephemeral <br />streams). The streams flow to the northwest of the permit <br />area where they empty into Hardscrabble and Coal Creeks. <br />Hardscrabble Creek is an ephemeral stream while Coal Creek is <br />perennial. These two drainages discharge into the Arkansas <br />River which is the major perennial drainage in the area. <br />The base flow of Newlin Creek is diverted by the City of <br />Florence upstream from the Southfield permit area. This water <br />is carried across the permit area by a 12" pipeline. EFCI has <br />monitored both the Newlin Creek streambed and the Florence <br />pipeline for subsidence since 1984. During the following four <br />years of monitoring, maximum vertical changes for the Newlin <br />Creek streambed and the Florence pipeline were 0.6 feet and <br />less than 0.1 feet, respectively. <br />The Magpie Creek drainage was diverted around the mine <br />facilities area by Dorchester in 1982. The drainage and <br />diversion are discussed in the permit in Exhibit 19, "Drainage <br />and Sediment Control". With the approval of Technical <br />Revision 15, December 1993, designs for the permanent <br />retention of Magpie Creek were incorporated into the permit. <br />The creek stabilization will be in three phases, with the <br />first one to begin this year. <br />Monitoring of Magpie Creek to date has consisted of flow <br />measurements on sampling days once each quarter. Peak flows <br />in Magpie Creek need to be measured to provide data for <br />restabilization of the creek for permanent diversion status. <br />Therefore, the following stipulation is included here. <br />Stiaulation No. 14 <br />ALL PEAK FLOWS SHALL BE MEASURED IN MAGPIE CREEK AT THE <br />CURRENT MONITORING STATION. DATA ACQUIRED FROM THIS <br />MONITORING SHALL BE SUBMITTED QUARTERLY AND INCLUDED IN THE <br />ANNUAL HYDROLOGY REPORTS FOR THE MINE. <br />Second Alkali Creek is an ephemeral drainage which crosses the <br />northern end of the proposed permit area expansion. Since <br />there will be no surface disturbance in this area other than <br />possible subsidence, the mine is not expected to affect Second <br />Alkali Creek. <br />36 <br />