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The replacement pipeline section is about 5,700 feet long out of a total pipeline length of <br />about 12,600 feet It is constructed, for the most part, from 24 -inch HDPE pipe. The <br />replacement pipeline does not connect directly to the 3 Dam collection pond, but <br />connects to the existing 14 -inch seepwater pipeline at the "1/2 way cutout' valve. The <br />existing 14 -inch HDPE pipeline conveys the seepwater the rest of the way to the 3 Dam <br />collection pond. <br />The 14 -inch section of the existing seepwater pipeline was not replaced as ` part of this <br />project because it will be abandoned when the mine starts up. Tailing deposition will <br />occur on the Mayflower Tailing Storage Facility (TSF) and the 5 Dam seepwater will be <br />discharged into the TSF water pool, eliminating the need for the 14 -inch section. <br />To address the issue of the removal of scale in the new seepwater pipeline, a pig <br />cleaning system was installed as part of the new construction. This system will allow the <br />new section of pipeline to be cleaned at any time during the year. In addition, cleanout <br />tees were installed in the pipeline at approximately 900 -foot intervals to allow for the <br />traditional hydro-jetting process to be used, if necessary. <br />Pipeline <br />While most of the new seepwater pipeline is constructed from HDPE, the first section of <br />the pipeline from the pump station to the pigging vault is constructed from 316 stainless <br />steel. This was done due to pressure limitations of the HDPE pipe and fittings. The <br />stainless steel portion of the pipeline is constructed from 12 -inch pipe. While this size is <br />smaller than the rest of the pipeline, the length is short enough not to cause significant <br />pressure Toss. <br />The majority of the 5 Dam Seepwater pipeline is constructed from 24 -inch HDPE pipe of <br />various wall thickness. The wall thickness of the pipe is decreased as the pipeline gains <br />in elevation and the operating pressure is reduced. DR 7 pipe was required at the pump <br />station end of the line and the pipeline wall thickness was reduced to DR 17 at the upper <br />end of the pipeline, which is relatively low pressure. All of the new HDPE pipe sections <br />had a 12 G copper wire installed above the pipe to help locate it when buried. The <br />copper wire daylights at the vaults and deanouts and connects to test stations at these <br />locations. <br />Page 2 of 6 <br />