On 08.10.2013 the final breakthrough for the 5.7 km-long New Irvington tunnel was recorded. The new tunnel, parallel to the existing tunnel, connects the Alameda Siphons in the Sunol Valley to the Bay Division Pipelines in Fremont, California used by 2.6 million customers. Excavation started in August, 2011 using three roadheaders from four separate headings at depths between 9.14 m and 213.36 m. The inner diameter is 2.6-3.2 m. The 2.6 m-diameter steel pipe lining will be inserted into the tunnel in 15.24 m sections which will be welded together. Click us/49 for tunnelbuilder archive. Visit http://sfwater.org/bids/projectDetail.aspx?prj_id=138. 45/13.