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-2- Prior to September of 1982 the monitoring requirements for these sites were quarterly with TRC eliminated from monitoring until one year prior to mining in the Moffat Area. In addition, P8d~1 committed to monitoring site TR-E to be located at the flow monitoring site on the draw between West Ridge and Center Ridge and to collecting samples for water quality analysis from the sediment ponds. As far as the Division's records show, no samples have ever been taken from the above mentioned areas. In September 1982 the Division approved a revision to monitoring frequency and parameters. As apart of this revision sampling is now tri-annually. This will be discussed in further detail in a later section. Based on data received from ongoing monitoring at sites TRA, TRB and TRD it is difficult to substantiate the predicted effects of mining of the water quality of Trout Creek. This is due to several factors outlined below. The predicted impacts of TDS levels on Trout Creek from mining in the West Ridge Area were estimated to be an average increase of 3 mg/1 with a maximum increase of 16 mg/1 during low flow periods. (I find their calculations to be in error and my numbers are an average of 8 mg/1 with a maximum of 28 mg/1). The data from the last several years of monitoring indicate a probable increase in TDS levels, to a maximum high value at TRD 640 mg/1 in 1982, but several things must be taken into consideration when evaluating this data. Monitoring frequency is such that the maximum and minimum TDS levels may have been missed. That would mean maximum TDS levels are actually higher than it appears on the included graph. In addition, TRC has been eliminated from monitoring until one year prior to mining in the Moffat area. This means that there is no data from this site which showed the consistently highest TDS levels in the baseline study. While it would be logical to assume that these levels have not increased since baseline, there is no evidence to support that assumption. Therefore, it can not be concluded whether there has been an increase in TDS levels directly related to mining in the West Ridge Area. In fact, data is such that it is difficult to predict if there has actually been an increase. Since flows have been so much greater the past 2 years especially during late summer - early fall, it does appear that during this period there has been an overall decrease in TDS levels. During the period Trout Creek has been monitored TDS levels have not exceeded 1,000 mg/l. The maximum observed levels at site TRC (indicative of waters entering the Homestead Irrigation Ditch) and at TRD (indicative of water as it leaves the permit boundary) are just over 600 mg/1. This is of special concern at site TRC because the high levels occur during a time when this water might be used for irrigation and because levels at this site will probably increase when mining begins in the Moffat area. This will need to be closely watched in the future with the monitoring program revised to reflect this. The high levels at site TRD occur during low flow in spring and late fall. THese will also need to be watched but dilution will have an effect on these levels prior to use downstream.