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will be cons1derably less than this predictton, due to the lim1ted amount of contributing rainfall. The applicant projects there will be no spoil discharge. Any spoil spring discharge would be of relatively poor quality, perhaps 2 to 3 times higher in Total Dissolved Solids than background water quality, but would be easily diluted to background quality prior to any use downstream. The applicant will conduct an annual spoil spring survey which will verify these projections. Any springs with discharge of at least 10 GPM will be identified and sampled for a full suite of parameters, with a report to be submitted to the Division by June 15 of each year. The applicant has aiso committed to replacement of any adjudicated source of water which may be impacted by the proposed mining operation, as would be required by Colorado water law. Surface Water The probable hydrologic consequences of mining activities to surface water in the proposed Hamilton Mine permit area will result from alterations to runoff characteristics, surface configuration, and water quality. Totai dissolved solids (TDS) for Naturita Creek, vary from 900 to 1,750 mg/1, and are much higher than for the San Miguel River, which has a weighted average TDS of 316 mg/l. According to data provided by Lillylands, Inc. sulfates vary from 500 to 963 mg/1 in Naturita Creek water, whereas San Miguel River water generally has less than 100 mg/1. Levels of calcium, magnesium and potassium are aiso higher in Naturita Creek than 1n the San Miguel River.. Naturita Creek is suitable for livestock use. Mining activities are not expected to contribute significantly to changes in water quality parameters of either of these streams, except for total suspended solids (TSS) which is expected to decrease as a result of interception of water by sediment ponds. Total salt loading is expected to Increase somewhat due to exposure of materials not previously in contact with surface water, breakup of overburden by mining activities and concentration due to evaporation of water during retention in sediment ponds. Samples taken during runoff resulting from 1988 snowmelt and Storm events along Long, Center, Section 33 and Hamilton (referred to as Broad Creek in the permit application) Creeks show a variability in TDS from 5,080 mg/1 on upper Hamilton Creek following a storm, to 110 mg/1 on Upper Center Creek following snowmelt. Sulfates varied from 3,680 mg/1 on Upper Hamilton Creek during the same storm event .- 1: ;,:~ -20-