Laserfiche WebLink
Mill Water Supply Pipeline Replacement Project <br />Project Summary <br />March 2, 2010 <br />Completed by Amanda Hren <br />The Mill Water Supply Pipeline was installed in the early 1970's to transfer water from the East Branch <br />Pump House to the Mill Water Tanks. In October 2009, two excavations of the pipe were thickness tested, <br />as well as the exposed pipe in East Branch Pump House and the Mill Water Tank Valve Vault. The test <br />results stated that the pipe was below the allowable thickness for the stresses put on the pipe; therefore, a <br />new section of pipe was installed. <br />Approximately 1,600 lineal foot section of 36 inch diameter SDR 11 HDPE pipeline was placed in a trench <br />located to the south of the existing 36 inch diameter steel pipeline. The trench was excavated from East <br />Branch Pump House to a location near the sewer treatment plant in the South driveway. All surrounding <br />utilities, including the existing mill water pipeline, remained in service for the duration of the project. <br />An existing blind flange on the end of the discharge header at the East Branch Pump House was removed <br />and the new pipeline was connected. The pipeline exits the building through the exterior wall, and then <br />proceeds underground. <br />The connection of the new pipe to the existing pipe in the South entrance road required a section of the <br />existing pipeline to be removed. At this connection, a vault was installed for future installation of a pipeline <br />to pump directly from East Branch Reservoir. <br />Hydro testing was completed on the pipeline before it was placed in the trench per Plastic Pipe Institute <br />(PPI) recommendations. The test results showed that the pipe contained no leaks. <br />The Project was completed mid October 2010 on schedule and within budget. The pipeline was <br />implemented with no safety impacts and minimal environmental impacts. The completion of this project <br />ensures that the Mill Water Supply Pipeline will be capable of operating at desired conditions for the life of <br />the mine.