The Palo Alto Regional Water Quality Control Plant owns and maintains a 72-inch diameter underground trunk sewer constructed in 1972 and known as the Joint Intercepting Sewer (JIS), which conveys raw sewage from Mountain View, Los Altos, Los Altos Hills, and a portion of Palo Alto to the plant for treatment. Phase 1 of the Joint Intercepting Sewer Rehabilitation Project (this project) will rehabilitate the downstream portion (2,363 out of the 9,000 linear feet) of the sewer pipeline between Manhole No.4 (located on a gravel road adjacent to Byxbee Park) and the plant’s influent structure named JB-0. The proposed pipe rehabilitation will be of cast-in-place pipe (CIPP) method, which inserts a resin-impregnated cured-in-place liner into the existing sewer pipe though existing manholes. The liner is then filled with water that is heated to cure the resin and harden the liner in place. Temporary bypass pumping of sewage around the section of the sewer pipe being rehabilitated will be required to facilitate cleaning and inspection of the pipe as well as installation of the CIPP liner. The project will also include non-structural rehabilitation (concrete repair and corrosion protective coating application) of two manholes (MH-03 and MH-02) and a sewer junction box (JB-1).
Rehabilitating the sewer pipeline is necessary to support the Regional Water Quality Control Plant’s operation and to restore the sewer pipe’s service life.