City of Monterey Sanitary Sewer Collection System Rehabilitation Project

City of Monterey Sanitary Sewer Collection System Rehabilitation Project

The City of Monterey (City) approved the City of Monterey Sanitary Sewer Collection System Rehabilitation Project (project) on Sept. 3, 2013, which includes repair to or replacement of existing sewer pipelines, sewer manholes, and lift stations. The project includes rehabilitation of 441 sewer pipeline segments, 416 sewer manholes, and 7 lift stations. The Monterey City Council adopted a MND and Mitigation Monitoring and Reporting Program on Sept. 3, 2013, prior to the approval of the project . The current project consists of modification to the approved Sanitary Sewer Collection System Rehabilitation Project with addition of 104 manhole structures that may need to be repaired or replaced when the attached sewer line segment is repaired or replaced. These existing structures were not identified for rehabilitation or repair in the adopted MND; however, all manholes are on sewer lines that were evaluated for repair and/or replacement in the 2013 IS and MND. Subsequent to the adoption of the MND, the City determined that these manholes may be damaged during repair or replacement of the sewer lines and are including the structures for potential repair or replacement. The following repairs are proposed on federally owned lands: 1) three existing manholes have been added at the Naval Postgraduate School (Dept of the Navy); and 2) three existing manholes have been added (600, 601, 602) at the Presidio of Monterey (Department of the Army). Proposed manhole rehabilitation activities may include repair or replacement. Repair would involve the application of a polyurethane coating to the interior of each manhole to reinforce existing concrete or brick walls. The application of this coating would require no ground disturbance. In the event the contractor determines that cured-in-place pipe treatment is not possible, pipe bursting would be proposed, and the connecting manhole may need to be removed/replaced if it cannot be burst through. In the worst-case scenario, replacement of the manhole may be required, which would result in excavation to remove and replace an existing 48-inch diameter manhole. The area of excavation would be an approx. 96-inch diameter area excavated to the depth of the manhole, which can vary from approx. 3.5 to 9.05 feet.

Monterey

Monterey