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1 J &T Consulting, Inc. <br />2013 J&T Consulting, Inc. <br />CONE OF DEPRESSION / RADIUS OF INFLUENCE CALCULATIONS <br />Loloff Construction <br />M1985 -112 <br />Reference: "Groundwater and Wells - Second Edition ", Fletcher G. Driscoll <br />Well flow in unconfined aquifer at equilibrium <br />(Reference attached literature for explanation of methodology & variables) <br />Case 2 - With Recharge <br />K(HZ –h2) <br />EQ9.1: <br />Q— R � <br />H= <br />1055 log <br />ft <br />h= <br />Case 1- <br />No Recharge <br />K = <br />1000 gpd /sq -ft <br />H= <br />37 ft <br />h= <br />Oft <br />Q = <br />3000 gpm <br />r= <br />600 ft <br />Case 2 - With Recharge <br />K = <br />667 <br />gpd /sq -ft <br />H= <br />37 <br />ft <br />h= <br />Oft <br />Q = <br />3000 <br />gpm <br />r= <br />600 <br />ft <br />LK(HZ –h2) log = K 1055 Q z) R = r10 1055 Q <br />R= 1624 ft (From center of pit) <br />R-r(mining limit)= 1024 ft (Beyond mining limit) <br />R= 1166 ft (From center of pit) <br />R- r(mining limit)= 566 ft (Beyond mining limit) <br />Note: Recharge assumed to be 1000 gpm, which equates to 33% of total <br />dewatering pumping rate, therefore inflow (K) reduced by 33% to 667 gpd /sq -ft. <br />1 oft <br />7/3/2013 <br />