Laserfiche WebLink
4000 0 <br /> 3500.0 <br /> 3000.0 <br /> 2500.0 <br />J <br />E 20000 <br /> 4 <br /> 1500.0 <br /> <br /> 1000.0 <br /> <br /> 500.0 , • • <br /> I ¦ <br />0.0 " <br />0.0 <br />10.0 20.0 30.0 40.0 50.0 60.0 <br />Flow (CFS) <br />Figure 4 - Tuttle Draw TDS v. Flow <br />The above flow and TDS data is from 1981 to 1987 for pre mine, and 2001 to 2008 for <br />post mine conditions. The base flow in the Draw is 0-5 cfs. TDS under these conditions <br />ranges from 500 to 3400 ppm. Upstream TDS at sample point SW-N1 is roughly 1000 <br />ppm lower than downstream TDS shown by SW-N3. This is true in both pre mine and <br />post mine conditions. The Tuttle Draw is the receiving water for a substantial area of <br />agricultural irrigation run off from the north in addition to mine surface run off. This leads <br />to increased total dissolved solids (TDS). <br />The pre mine and post mine TDS values at each sample point are in the same ranges. <br />At base flow SW-N1 has a TDS ranging from 500 to 2000 ppm in both pre and post <br />mine conditions. SW-N3 has a TDS ranging from 1000 to 3500 ppm in both pre and <br />post mine conditions, at base flow. When flows increase due to storms, both SW-N1 <br />and SW-N3 show a corresponding TDS drop off due to dilution from the increased flow. <br />The data shows no inconsistencies that would require quarterly monitoring. <br />Tuttle Draw TDS vs. Flow <br />• SW-N1 Pre Mme <br />• SW-N1 Post Mine <br />SW-N3 Pre Mule <br />SW-N3 Post Mine