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~aoniioring of this well. Therefore, monitoring of Well GS-545 PI ~dili cpniinue as approved. RESPONSE: Peabody agrees with this concern. The language in the last paragraph of Tab 7, Section VII b.2.a. has been changed to concur with the above request. COMMENT: (PHC) The Division is concerned that some of the assumptions used to calculate the salt loading impacts to Fish Creek may not be valid. Specificai]y, the Division believes that the use of the Wadge outfall ;eater quality for predictive purposes in the "Caw Camp" and "Bond C~•eek" drainages may not be appropriate. It is felt that such factors as surface water inflows, residence time :•~ithin the impoundment and mixing in the impoundment must be carefully anal;~zed if the outfall water quality is to be used for comparative purposes. Furthermore, the implications that the quality of spoils • spring discharges in the Covr Camp Creek Drainage will reach a worst case condition within eight years should be carefully considered. The Division feels that the time sequence of mining the Cow Camp Creek drainage should be used as a r"actor in the prediction of worst case conditions. The Division believes that to predict the worst case spoils discharges to Fish Creek, the following assumptions must be used. (Z) In a dry season, the majority of flow past points 007, 004 v:ill be contributed by spoils discharges. Surface flow contribution will be negligible; (2) low flow of Fish Creek will approximate base-flow discharge; (3) the quality of spoils discharges will approximate the observable quality of wells GW-525, -526, -527; (4) discharge from spoils springs may be estimated by calculating current spoils spring discharge in Cow Camp Creek versus current disturbance area in this drainage. This discharge per unit area may be applied to projected disturbance in the Cow Camp and Bond Creek drainages. After worst case conditions have been determined, • 20