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<br /> <br />flat car which is long enough to span the creek and strong enough <br />to support heavy construction equipment. The bridge will be left <br />in place until reclamation of the portal area is complete. <br />A new drawing number D-2-4 has been prepared to show how the <br />seepage is being controlled and piped to the treatment ponds. <br />The french drain, bentonite filled trench, treatment ponds, <br />bridge and piping system are all shown on the new drawing. <br />SBEPAGB TREATMENT <br />A sample of flow being intercepted and piped to treatment ponds <br />wsa taken on May, 9 1988 and results of the analysis of the <br />sample are as follows: <br />pH 6.8 <br />Temp. ^C 14 <br />E/C mmhos/cm 4.03 <br />Dissolved Solids mg/1 2810 <br />Suspended Solids mg/1 2180 <br />Recoverable Iron mg/1 120.6 <br />Recoverable Cadmium mg/1 0.00090 <br />Oil and Greece mg/1 < 5.0 <br />Flow gpm 30.0 <br />Two separate titration testa were performed on the above sample <br />to determine how to treat this water. The pH of the water was <br />increased with sodium hydroxide and then the sample was allowed <br />to settle .for 24 hours. Results of the analysis oP the water <br />samples after a 24 hour settling period are as follows: <br />Titration pH 8.5 9.0 <br />pH after 24 hrs. 8.05 8.24 <br />E/C mmhos/cm 3.90 3.77 <br />Dissolved Solids mg/1 2780 2715 <br />Suspended Solids mg/1 < 10 < 10 <br />Recoverable Iron mg/1 1.54 0.63 <br />Recoverable Cadmium mg/1 0.0007 0.0007 <br />Oil and Grease mg/1 < 5.0 < 5.0 <br />It was apparent from these testa that the water could be treated <br />by increasing its pH to allow the iron to settle out. A drip <br />feed system has been installed to accomplish this. The drip feed <br />system is using a 25% solution of sodium hydroxide as s buffer <br />feeding at about 2 gallons per minute into the 30 gallon per <br />minute stream. <br />Two treatment ponds were constructed on site, each with a surface <br />area of approximately 5,000 square feet. The ponds are both ap- <br />proximately five feet deep. The depth of the ponds is not as im- <br />portant as the pond's surface area in treating this type of <br />water. The ponds have a combined total capacity of about 75,000 <br />gallons in the top one foot of depth. At a flow rate of 30 gal- <br />