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-~ 71 <br />FEB 1 g 1980 <br />1985 HYDROLOGIC REPORT ~,,,_ <br />11 iii ~~rl! q}J~'~ ~, ., „~77 <br />- .. .:Ira,. <br />SURFACE WATER <br />The winter of 1984 - 1985 was a good year for snowfall. The estimated 25,000 <br />acre-feet of flow from Hubbard Creek for the year was considerably below the last <br />couple of years estimates. The spot monthly readings used to calculate the total <br />flow for the years were probably not representative of the entire month. Spring <br />runoff for 1985 was more gradual and uniform than the past two years. High flow <br />occurred May 4 with an estimated flow of 700 c.f.s. The lower sampling location <br />on Hubbard Creek was changed in April from near U.S. Steel's Hubbard Creek fan <br />to a location 500' south of our permit boundary. Between the upper and lower <br />Hubbard Creek sample points the mass average TDS declined from 205 to 144 mg/1 <br />while the mass average conductivity for the same samples rose from 138 to 165 <br />umhos/cm. The TDS appears to be a lab error but the sample location will also <br />be checked for inadequate mixing. <br />The 111 Pond Discharge (NPDES 001) continued on a regular basis until October when <br />the mine discharge was changed to direct discharge into Hubbard Creek via NPDES <br />004 discharge point. The total flow from the pond for 1985 was calculated to <br />be 156 acre-feet of which 85 acre fee[ was from mine discharge. The majority <br />of the remaining flow from the pond was springs. The water level in [he pond <br />was kept low in the pond until the first week in November when the recovery of <br />dirt stored in the pond for the bench project was completed. At that time the <br />water storage drain was closed to allow [he water level to reach the dewatering <br />device for discharge. By the end of the year the water level was within a Eew <br />inches of the dewatering device. The mass average TDS for the year was 673 mg/1 <br />which would have had an average affect of 4.2 mg/1 increase in TDS for Hubbard <br />Creek. Due to total iron problems with discharge in the past an application was <br />made to the Colorado Department of Health to raise the limit Erom 1 mg/1 average - <br />2 mg/1 maximum to 3.5 mg/1 average - 7 mg/1 maximum. These new limits were approved <br />in a new permit issued September 26, 1985. <br />Ponds 113 and 114 had no reportable discharge during the year. <br />Due to problems with continuous discharge from the 111 pond associated with mine <br />discharge an application was made to the Colorado Department of Health for a new <br />