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Section 780.21 (b) Continued. <br />J <br />Increased permeability and exposure of any possible toxic, acid- <br />or alkalinity-producing material to water can result in dissolution <br />of toxic material and possible changes in pH values. If such water <br />comes into contact with a recharge zone, the quality of ground <br />water is similarly changed. <br />Placement of sedimentation points on top of spoils can increase the <br />amount of water available for leaching through spoils. This can <br />cause an increase in the TDS concentrations and a change in the ion <br />balance of water within the spoils which could possibly enter a <br />ground water aquifer. <br />A detailed discussion on leaching and the effects of mining on <br />ground water quality is presented under paragraph (c) of this <br />Section. <br />• Methods of Protection and Mitigation. Leaching within the mine <br /> plan area is unavoidable whenever water saturates spoil material. <br /> Leaching could be avoided by insulating spoil against saturation, <br /> but this is not only impracticable or impossible on an operational <br /> basis, but would prevent recharge of the aquifer adjacent to the <br /> spoils. Once leaching has occurred, there is no practicable tech- <br /> nology currently available to treat the water to decrease TDS <br /> concentrations. The only method, therefore, to minimize the im- <br /> pacts of mining and leaching on ground water quality is to minimize <br /> the amount of water which can pass through spoils. Two types of <br /> spoil disposal are proposed within the permit area. One is to <br /> sidecast or move spoil into the previous cut or mined areas as <br /> mining progresses. The second is to haul and stockpile excess <br /> spoil away from the pits. In the first case, the primary means of <br /> minimizing water flow through the spoils will be to regrade, retop- <br /> soil, and revegetate the mined areas as soon as possible following <br /> coal removal. This will have a dramatic effect on minimizing the <br />• amount of water entering the spoils. In fact, according to Lusby <br />760-166 <br />