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-3- Oak Creek The P&M load-out facility is the only mine related disturbance located in the Oak Creek drainage. Oak Creek is a perennial stream. It's confluence with Trout Creek is located just downstream of the mine site. From the baseline study, peak flows on Oak Creek occur in early May and are usually around 100 cfs. The high flow period runs from late April to early June. Minimum discharge on Oak Creek is 5 cfs and occurs in late fall, just prior to winter freeze-up, and in early spring. For baseline studies there was one station established to monitor surface water flows. The flow patterns for the past 3 years have not differed from the baseline study except that, generally, the flows have been somewhat higher. There were 2 sites established on Oak Creek for water sampling, one upstream from the permit area and the other downstream. These monitoring sites are also part of the continuing monitoring program. Oak Creek generally exhibited poorer water quality than Trout Creek at both the upstream and downstream monitoring sites. Water in Oak Creek is of the calcium sulfate type. TDS levels approach that of the levels at sites TRB and TRC on Trout Creek (average approximately 500 mg/1 with a maximum of approximately 800 mg/1). These higher TDS levels are explained in the permit application as being caused by significant construction along Oak Creek. There are also several abandoned mines upstream from which water empties into Oak Creek. The most often exceeded EPA criteria were those for iron, manganese and zinc at both monitoring sites. As predicted, continued monitoring indicates that mining has had little effect on Oak Creek. All values are within those values established in the baseline study and, due to dilution caused by heavier than normal flows, in most cases a slight decrease is evident. C. Other There are two active irrigation ditches taking flow from Trout Creek near the permit area, the Homestead Ditch whose headgate is adjacent to the Moffat Area and the Koll Ditch whose headgate is upstream of the permit area. P&M has installed flumes to measure the flows in these ditches. The records are presented in the annual reports. When surface water site TRC is reestablished it will provide records of the quality of the flow going into the Homestead Ditch. P&M has tried to install a flume to monitor flows in the drainage between Center Ridge and West Ridge. Because of high flows in 1982 the flume was destroyed. P&M committed to installing a heavier and larger flume in 1983 which was again destroyed. Further discussion can be found in the comments section of this report.