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<br /> <br />BO CW 55 <br />Peabody Coal Co. <br />Page 9 <br />calculations of anticipated dewa tering rates <br />and volumes. 'The drawdown in the shallow <br />aquifer (ovetburd en) due to dewa ter ing and <br />the volume of pit in Flow resulting were <br />- calculated. After five years of mining <br />activity [he drawdown will reach its maximum <br />amount and will remain constant the reaftzr. <br />The maximum drawdown will be 1.0 feet at a <br />distance of 0.7 miles from the [JUCla East <br />- pit. The volume of water entering the pit <br />is calculated to be 43.8 of per. year. ' <br />(d) Mitigation is only required whe re existing <br />water users might be impacted. An an al ys i.s <br />of existing surface and groundwater uses in <br />the vicinity was made. All.but two, of, the <br />existing domestic wells in"'the area use a <br />different (deeper) aquifer than the. one <br />affected by pit dewa tering. The two <br />remaining wells are in the impacted aquifer, <br />but should not be adversely impacted because <br />. of the moderate drawd owns occurring.. <br />Applicant proposes to monitor the se~~o <br />('" wells and wi I'1 mitigate any impacts <br />• _ demonstrated"although none.are, an.tic,ip~ted. <br />The Court rs"chntinuing jurisdiction will <br />allow a review of monitoring results and <br />modification of this of an of augmentation if <br />additional mitigation is required to prevent <br />adverse impacts on these shallow wells. <br />(e) The engineering study determined that only <br />surface water users might be adversely <br />~impac ted by _pit,dewa tering. These-users <br />only. diver t_dur. ing tt~e historical~~irri~ation <br />~seaso ~,'and`mit ig ation `is only requl fed <br />ducing~ this ~period.~ P.q.~infl ow~Gil1•occur <br />a t'~a ~~un ifo nn rate of 0_.12 of"per„day, <br />throughout the'~year .~~DUr ing the irrigation <br />season, pit inflow will total 24.1 af. It <br />is conservatively assumed that all pit <br />inflow during the irrigation season will <br />impact the identified surface rights. The <br />amount~of impact o.n each user was determined <br />from calculated drawd owns at that user's <br />point of diver. Sion. To adjust for'"~t im ing <br />delays, delivery losses, and any variation <br />in assumed conditions, the mitigation water <br />• <br />REVISED MARCH 2006 Attachment 2.05.3(3}16-30 <br />