AgdaPkt 2010-08-23 - Laserfiche WebLink

Browse Search

6.1 B REP4RT To the Honorable Mayor and City Council From the Cit Mana er August 23, 2010 SUBJECT Professional services agreement for preliminary engineering design for the Walnut Street Interceptor Sewer Replacement Project. RECOMMENDATION !,, Approve, by motion, the standard form professionai senrice agreement with RMC Water and Environment of San Jose to provide pre[iminary engineering design services for the Walnut Street Interceptor Replacement Project in an amount not to exceed �119,149.00 and authorize the City Manager to increase the contract amount up to 10% if necessary. BACKGROUND A "sewer interceptor" is a large sewer line that collects and directs flows ftom other sewer lines to the treatment facility. The existing Walnut Street Interceptor was constructed circa 1970. It is a 48-inch diameter gravity sewer main that conveys the flows generated by customers within the city's jurisdiction and the county's Sewer Maintenance District (Fair Oaks, Emerald Lake Heights, Oak Knofl, Kensington Square, and Scenic Heights} from the west side of U.S. Highway 1�1 to the Maple Street Pump Station which is located east of the highway. The existing reinforced concrete pipeline is encased in a 66-inch welded steel pipe beneath the highway. All wastewater generated west of U.S. Highway 101 is carried through this single pipeline to the Maple Street Pump Station and subsequen#ly pumped into the South Bayside System Authority's (SBSA) conveyance system for treatment at the SBSA's wastewater plant. The Walnut Street Sewer Interceptor Replacement Project is necessary to ensure the continued reliability of the wastewater collection system as it is a critical component of the collection system. The existing pipeline was assessed using closed circuit television (CCT� and sonar technology in April of this year by AquaCoustic Remote Technologies Inc. The results of that assessment indicate that the pipeline is structurally sound without any noticeable cracks, however the interior walls of the pipe are excessively worn as evidenced by concrete aggregate that's been exposed the entire length of the pipeline. The objectives of the preliminary engineering design for the Walnut Street Interceptor Replacement Project include: • Preliminary evaluation to determine the feasibility of installing a parallel pipeline to provide system redundancy, � Geotechnical investigation to evaluate the soil condition to better assess the suitability of a "trenchless" repair technology alternative, and • Design of transition structures to provide connection points for existing and future collection system pipelines. In April 2010, staff solicited Requests for Proposal (RFP) to four qualified engineering consultants. All four consultants (Kennedy/Jenks, Winzler & Kelly, West Yost, and RMC Water and Environment) responded to the RFP. RMC Water and Environment was