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<br />Ground water quality in the permit area has been affected by extensive <br />underground workings, hence, ground waters are no longer "natural", but rather <br />have been affected by oxidation. Increased oxygen in the ground water has <br />accelerated weathering reactions of minerals present in the coal and rock strata. <br />Increased oxygen in ground water or mine waters can increase the concentration of <br />iron, sulfate, calcium and bicarbonate in solution. <br />Ground water in the permit area falls into one of two groups eharacter- <br />ized by TDS levels. High TDS waters (greater than 1000 mg/1) are associated with <br />abandoned underground workings, while low TDS ground water (less than 1000 mg/1) <br />are dominantly "natural" waters with little or no effects from the underground <br />workings. High TDS waters are a sodium sulfate-type water, while low TDS waters <br />range between sodium bicarbonate and sodium sulfate/bicarbonate waters. This <br />variance in the low TDS water chemistries reflect both changes in chemistry which <br />normally occurs along a flow path, and the incorporation of a small component of <br />• ground water from old underground workings. <br />Deep well water quality varies over the site from formation to <br />formation and within formations. Three wells were sampled in Hydrologic Sector I <br />with the types of waters varying from a strong sodium sulfate type at W82-11C to <br />a sodium sulfate/bicarbonate type at W82-12L, to a strong sodium bicarbonate type <br />at W82-lOW. The waters ere moderate to highly mineralized with moderate <br />concentrations of iron and low concentrations of trace metals. This high degree of <br />variation is caused by the degree of oxidation from the underground mine workings. <br />Four wells were monitored in Hydrologic Sector H (W82-4L, W82-4C, <br />W82-5R and W82-8T2). Water quality within in this sector compares closely. The <br />water in all of the wells is a sodium bicarbonate with moderate mineralization, <br />SAR and iron concentrations. All of the wells exhibit low concentrations of trace <br />metals. <br /> <br />-11- <br />