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ENVIRONMENT, INC. <br />APRIL 26, ZO1 O <br />PAGE 4 <br />Yes, there is a monitoring plan. It is the same as in place <br />now, we will continue to check groundwater levels in the <br />monitoring holes monthly during the life of the mine. Some <br />monitoring wells will be removed during mining but there are <br />enough wells around the perimeter of the site, which will not <br />be disturbed, to provide the information-needed. We believe <br />that as the slopes are rebuilt-around the mined area the <br />amount of ground water entering the excavated area will be <br />reduced significantly.to the point that there will be little <br />ground water drawdown outside the mining area. <br />During the 3 plus years of data we have collected analysis <br />shows that the ground water level varies as much as 8 plus <br />feet from month to month, year to year. The largest average <br />change-has been 8.06 feet in one month for MW5. This was when <br />no dewatering was taking place on.the site. MW5 is located at <br />the highest point on the mine in the-southeast corner. On the <br />lower level the largest fluctuation was in MW6 which usually <br />occurs between August and September, where the average drop is <br />6.16 feet. Because of these highly variable changes, we <br />believe that choosing a set elevation or depth is impractical. <br />It will take a case by case review each month to find any <br />changes that could affect outside the mine area. L.G. <br />Everist, Inc., proposes implementing corrective actions when <br />groundwater level at the exterior monitoring holes have <br />dropped'5.0 feet or more from the monthly average drop <br />established during monitoring. Corrective actions may include <br />but are not limited"to any one or combination of.the following <br />actions, halting dewatering; constructing an aquifer recharge <br />trench between the dewatering area and the affected well; <br />supplying water to the affected well owner until the impacts <br />are mitigated, deepening the affected well or drilling a new <br />well. <br />What is the anticipated pumping rate for the site? <br />Our NPDES permit.currently.allows for 8.6 Mgd. We estimate <br />the water pumping rates could vary between 1.0 Mgd and 8.6 Mgd <br />depending on the dewatering needs as mining progresses. <br />Has there been. any aquifer drawdown modeling done for this site? <br />There has been no aquifer drawdown modeling done for this <br />site. <br />How will water that is currently captured by the "Seep Ditch" be returned when this ditch is removed? Or <br />will irrigation of these areas cease prior to removing the ditch? <br />It will enter the lake area during mining and be.discharged <br />-under our NPDES permit. Once the lake is complete it will <br />enter the lake area and be returned to the ground water system <br />via absorption. From what I can tell most of the water in <br />this seep ditch occurs when the ground water raises during <br />irrigation season and the ditch acts as a ground water <br />elevation control ditch. The irrigation on the mine site <br />south of,the ditch will be suspended but we suspect some <br />seepage that enters the seep ditch is from up gradient.. <br />irrigation and leakage from the Sidehill Ditch that <br />subirriga.tes this area. A previous owner built this private