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EFFLIIENT MONITORING <br />• Two sediment control structures M3-S (Station 76) and M3-N (Station <br />24) are monitored at Mine 3. Pond M3-N (Station 24) is located at <br />the reclaimed area immediately north of the confluence of Foidel <br />Creek and Middle Creek and controls runoff from reclaimed areas <br />from the abandoned Middle Creek underground mine. Site 24 is <br />subject to the limitations set forth under NPDES Permit COG-850013. <br />Pond M3-S (Station 76) is located south of the confluence and east <br />of Middle Creek and controls runoff from reclaimed areas east of <br />Middle Creek. Site 76 is subject to the effluent limitations set <br />forth under NPDES Permit CO-0027154. <br />Flows <br />The flow rate data for the effluent sites are provided in the <br />tables attached to the report. Maximum 1992 flow rates are <br />compared with historic maximum flows in Table 14. Discharge from <br />these ponds is low and infrequent. Discharges from these two ponds <br />occur only as a result of large precipitation events. Only six <br />discharge events were detected at Station 24 during 1992 and only <br />seven discharge events were detected at Station 76 in 1992. All <br />the 1992 discharge events occurred during spring runoff, with the <br />exception of a single discharge from Site 76 in July. This <br />discharge was in response to a convective storm event which <br />• produced locally heavy precipitation. <br />Water Quality <br />The water quality data for 1992 for the two effluent sites are <br />provided in the tables attached to the report. Specific <br />conductance plots are also included on Figure 21. Record summaries <br />included on Tables 21 through 24 shows that the discharge from <br />these sites did not contain constituents that would have a <br />detrimental effect on the water quality in Middle Creek. Neither <br />site is exhibiting any long term trends in specific conductance. <br />• Paqe 8 <br />