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and rainfall could be a likely source of water infiltration through the dumps, which would move metals into Windy Gulch. Six inches of topsoil on the 9700 level dump may be sufficient to control infiltration, if good vegetative cover is established. However, we wonder about the success of getting 6 inches of cover across the whole dump, given the steepness of dump slopes. Infiltration is less of a concern on these steeper slopes, but erosion of metal laden sediments into Windy Gulch is a greater concern. Both infhration through the dumps and erosion of dump material should be dealt with in the reclamation plan. No cover is provided for the 9360 level dump with this reclamation plan. Again it would be very difficult to get a cover on the steep slope above Windy Gulch. There is also very little, to no cover on the rest of the 9360 dump. The overflow channels aze an important component to handle the less frequent storm event flows, but we would recommend that an impervious liner be considered to minimize infiltration of water from these flood flows. Should pipes get plugged or collapse in the future, much more water than is anticipated now could move through the overflow channels. We also noticed the lack ofrun-on controls to prevent runoff from flowing onto the dumps. The Committee has considered this a routine component for other mine sites in the watershed. 3) Maintenance Maintenance of these ficilities will be required over the long-term Pipes that aze constructed several hundred feet through the dumps will eventually require some maintenance. We understand that the existing pipe in the 9360 dump is either plugged or collapsed at this time. Surface coverings of the dumps may become eroded over time. A means of accomplishing long-term maintenance of work performed now, should be addressed and included in the reclamation plan. 4) Performance Standards There is enough uncertainty about whether proposed reclamation will be successful that the Committee would like to encourage the establishment of performance standards. After talking with the State Division of Minerals and Geology and the State Department of Health, we would like to make a proposal The segment of Willow Creek that includes Windy Gulch has designated beneficial uses of agriculture and Class 2 recreation. Performance standazds then could be defined by the water quality standazds for those uses. For example, agricultural use has a standazd of 2000 micrograms per liter for total recoverable zinc. Phil Hageman, with the Colorado Department of Health (phone 303-692-3518) suggested that we use this approach.