Yosemite Valley Northside Drive Trunk Sewerline Replacement

Yosemite National Park » Yosemite Valley Northside Drive Trunk Sewerline Replacement » Document List

The work includes replacing 5800 linear feet of the existing clay-trunk sewerline with a new high density polyethylene (HDPE) sewer line of similar diameter. This is the segment of trunk sewerline along Northside Drive between Hanging Valley View and Pohono Bridge. The proposed line placement will be under the road in the southernmost lane of Northside Drive, whereas the existing sewerline is the northernmost lane. Ground disturbance includes a 3' wide and 8' deep trench. The existing clay sewer line is 30 years old with documented cracks. This sewer line needs to be replaced as part of the Yosemite Valley Loop Road project to minimize the risk of spills into the Merced Wild and Scenic River. This sewerline segment of Northside Drive will be completely torn up as part of the Yosemite Valley Loop Road project, so this is the most efficient time to replace this failing sewerline. If we do not replace the line the risk of a spill is considerably greater, given that the new culvert locations will be placed within inches of the existing clay sewerline. Clay sewerline's are very fragile pipes, so the concern is that given the age of this sewer line and the amount of construction occuring in and around the pipe it will crack and require repairs or may cause a spill. Design will be completed by a consultant, Kennedy Jenks. Archeological and Native American monitoring will occur as deemed necessary by the appropriate park specialist.