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mg/l for 1993. This value is both lower than the baseline average of 697 mg/l and the • <br />baseline range of 620 to 768 mg/l. <br />NPDES 006. This site is located on a tributary to Hubberson Gulch referred to as the 006 <br />Gulch. Construction of the 006 Pond was completed October, 1989. This pond collects all <br />mine discharges from the south mining area. Site SG6 was located at this site prior to <br />the construction of the 006 Pond and, therefore, water quality data from Site SG6 will be <br />used for the baseline conditions at this site. Samples from NPDES 006 display a MgOa-SO <br />4 <br />type water with an average TDS value of 831 mg/l in 1993. This value is toner than the <br />baseline average of Site SG6 (1,969 mg/l). This decrease of TDS values is the result of <br />the impoundment of low TDS spring runoff. Review of the flow hydrographs indicate typical <br />seasonal variation due to snowmelt runoff in the spring. The first hydrogra ph supplied <br />shows data for 1993, the second shows all date collected since the site began discharging. <br />The TDS average this year is lower than that of last year (891 mg/l) due to an increase in <br />snowpack runoff. <br />The yearly average flow (from weekly measurements) since this pond began to discharge are: <br />1993 0.127 cfs <br /> <br />1992 <br />0 <br />036 <br />f • <br /> . c <br />s <br />1991 0.062 cfs <br />1990 0.055 cfs (pond did not completely fill until March 29, 1990). <br />Surface Water Site SW-52W-FG1. This site is located on Hubberson Gulch downstream of the <br />006 Gulch confluence. It has been monitored since July, 1979. Review of its hydrograph <br />shows the highest peak flow since 1986. Samples at this site display a MgCa-SD4HCO4 type <br />water with an average TDS value of 765 mg/l in 1993. This value is .lower than the 942 <br />mg/l baseline average but falls within the baseline range of 290 to 1632 mg/l. Water <br />quality data from NPDES 006 indicate that mining has had very little influence on TDS <br />values at Slte FG1. <br />NPDES 005. This sediment pond is located in the north mining area on a tributary to Dry <br />Creek referred to as the 005 Gulch. Construction of this pond was completed in July, 1992 <br />and the first discharge occurred on April 22, 1993. In 1993, samples from this pond <br />exhibited a MgCa-S04 type water with an average TDS value of 1,094 mg/l. The value is <br />loner than the baseline average of 1,788 mg/l (from baseline Site SGB). Due to a leak • <br />that was discovered in the dewatering line, this pond was deuatered from May 11 to June <br />10 <br />