Laserfiche WebLink
-. 1943 Annual Hydrologic Report <br />Page 2 <br />Surface Water <br />Water flow and quality on the Colorado River is monitored by the <br />U.S. Geologic Survey (USGS) at various locations. The closest <br />location is Station No. 09095500 which is located upstream <br />approximately 7 miles north east of the mine site. This location <br />is noted on the 1993 Hydrologic Monitoring Location map as being <br />5.1 miles upstream of the top edge of the map. Water quality and <br />flow from this site are used as a general representation of the <br />Colorado River upgradient of our mining operation. There is a <br />diversion to the Government Highline Canal, the addition of <br />Plateau Creek and the addition of other minor drainages between <br />the monitoring site and the mine site. Data Pages SQ-# will be <br />used this year and in the future to include information supplied <br />by USGS on this site. The total flow at this site for the year <br />was 3,379,000 acre-feet which amounts to 121% of the 1934-1993 <br />average flow. The estimated TDS load for the year was 1.57 <br />million tons. This estimated is made using a mass average <br />conductivity calculated with the monthly average flow and the <br />monthly average conductivity, total flow for the year and a <br />conductivity/TDS ratio. A conductivity/TDS ratio of 1.72 was <br />calculated from information on data page SQ-2. The low flow for <br />the year was recorded as 1150 CFS on December 20 & 21, 1992 and <br />January 5, 1993. As can be seen on data page SQ-4, conductivity <br />was not recorded on any of these days but a reading of 1200 was <br />made on December 19,1992. The closest pH reading to these dates <br />was 8.7 on December 15, 1992. <br />During the year there was discussion with the Division of <br />Minerals and Geology (DMG) concerning the significance of <br />monitoring the Colorado River above and below the mine site. <br />Primarily due to the dilution ratios, reinstatement of river <br />monitoring was not done during the 1993 permit renewal. Potential <br />for lab error is greater than measurable affects of our <br />operation. One set of river water quality samples was taken on <br />during the year while discussion was going on. The analysis of <br />the samples is given on data pages SB-2&3 and SC-2&3. Tables <br />593-1&2 have been prepared to summarize quality information <br />collected at these sites since 1979 and diagrams 593-1 thru 4 <br />have been prepared to graphically represent TDS and Total Iron <br />using a Lowess Smooth Plot. Diagrams 593-5&6 were prepared to <br />show a trilinear representation of the river water quality. <br />Comparing this the calculated TDS load in the River and the <br />potential maximum discharge of TDS near the end of September <br />1993, the maximum increase in the River's TDS as a result of mine <br />discharge would have been 0.3% <br />As noted in the introduction, a new flume was installed on upper <br />