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filled areas. The salient results and conclusions of the report are used as the basis for the following dl$CUSSIOn. <br />~s previously discussed under Section 779.14, no toxic or acid-forming materials have been identified in the <br />overburden, so the potential for degradation of groundwater quality due to increase levels of toxic elements or <br />acidity is limited. During 1984 and 1985, monitoring and sampling of groundwater discharges from reclaimed <br />spoil material near Sediment Pond F yielded direct information on backfill water quality. The results of these <br />analyses were included in the report, Backfr/I Hydrologic Evaluation, Eckman Park Mrr:es. The results showed <br />that water quality was very consistent and showed little variation with Flow rate. The flow rate does respond quite <br />markedly to increased recharge during snowmelt periods. The water quality of backfill discharge, based on <br />analyses of the Pond F spring discharge is typically acalcium-magnesium-sulfate type leaving a total dissolved <br />solids concentration of about 4,000 mg/l. <br />Recharge to reclaimed areas tends to be higher than in undisturbed areas. The increased permeabiliq~ of disturbed <br />lands may decrease with time as revegetation and consolidation of backfill material progresses. Rainfall <br />simulation studies indicate that infiltration rates for reclaimed lands may be slightly lower than pre-disturbance <br />conditions (Lusby and Toy, 1976). Lysmeter studies performed by the USGS at the nearby Seneca II mine <br />indicated a recharge rate of about 3 inches per year. Recharge at a similar rate has led to saturation of the older <br />~eclaimed areas at the Eckman Park operation and surface discharge at the toe of the reclaimed slopes from spoil <br />springs. The Eckman park mining operation has left backfilled areas updip from the unmined Wadge Overburden <br />sequence. Recharge to this bedrock unit will, therefore, be through the backfill material in this area. Based on <br />water balance calculations presented in [he report, Backfil! Hydrologic Evaluotron, Eckman Park Mines, it was <br />estimated tlta[ less [Ilan 5% of the recharge Co backfilled areas would eventually recharge the bedrock aquifers. <br />This is consistent with data that indicate that [he permeability of the undisturbed bedrock downdip from the <br />backfilled <br />f~ <br />1996 Permit Ren. Permit Renewal 780-144-15 Revised 3/18/97 <br />