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Home My WebLink About07-02-2013 c8 sewer line replacement spec 90916b FROM: Daryl R. Grigsby, Director of Public Works Prepared By: Matt Horn, Supervising Civil Engineer SUBJECT: SEWERLINE REPLACEMENT, SPECIFICATION NO. 90916B RECOMMENDATIONS 1. Approve the plans and specifications for the Sewerline Replacement, Specification No. 90916B. 2. Authorize staff to advertise for bids and authorize the City Manager to award the contract if the lowest responsible bid is within the Engineer’s Estimate of $785,000. 3. Approve the transfer of up to $192,900 into the construction phase of the project account at the time of project award from the Wastewater Collections Master Account. DISCUSSION Replacement of wastewater collection pipes is part of an ongoing program to replace aging and deteriorating infrastructure. This program has several objectives: 1) ensure reliable removal of waste; 2) reduce the need for emergency repairs; 3) reduce the need for preventive maintenance; and 4) ensure uninterrupted wastewater flow without health hazard or effluent leakage. This project will accomplish these objectives for part of the City’s wastewater collection system. The scope of this project includes replacing sewerlines in portions of Beach, Islay and Chorro Streets. The existing sewerlines are maintenance intensive and are operating beyond peak capacity. Portions of the existing sewer system will be increased in size from six and eight-inch diameter pipes to eight, ten, and 12-inch diameter pipes increasing the system’s capacity. Maintenance needs will be reduced because of the new and larger sewerlines. In 2011 work was awarded for replacement of these lines using pipe bursting, a trenchless installation method. The discovery of a ConocoPhillips oil line in close proximity to the existing sewerline resulted in some of the work being completed with conventional trenching. The increased cost of trenching and further contractual challenges reduced the project scope and not all the scheduled pipe replacements were completed. This contract will complete the remaining work. Experience and Reference Requirements This project will require the contractor to replace these sewerlines using a predominantly trenchless process. The two specified methods of installation are pipe bursting and pipe reaming. A trenchless process will allow for a high quality seamless pipe to be installed with minimal disruption. Previous bid experience has found that trenchless installations are typically less expensive than conventional trenching. While the trenchless installation process for sewerline replacement is advantageous in this situation, it requires a contractor with specific experience and expertise to complete this work. A contractor Meeting Date Item Number 7/2/13 C8 - 1 Sewerline Replacement, Specification No. 90916B Page 2 with limited trenchless pipe installation experience could damage the sewer system, cause wastewater spills, and increase public inconvenience during the installation process. For these reasons, staff is planning to request the contractors to submit references for prior similar work utilizing the trenchless installation process. CONCURRENCES The Community Development Department has given this project a categorical exemption from environmental review. FISCAL IMPACT This sewerline replacement project was originally identified in the 2009-11 Financial Plan and carried over to the 2011-13 Financial Plan, Appendix B, on page 3-92. Supplement funding of up to $192,000 is requested from the Wastewater Completed Projects account, which has an available balance of $227,900 to support this request. Staff recommends transferring funding from the Completed Projects Account to the project account at time of contract award, based on construction bid amounts. ATTACHMENT Vicinity Map AVAILABLE FOR REVIEW IN THE COUNCIL OFFICE Plans and Special Provisions t:\council agenda reports\2013\2013-07-02\sewerline replacement spec no 90916b\90916b advertise.docx Estimated Project Costs Construction (Engineer's Estimate):$785,000 Construction Contingencies:$78,500 Total for Construction:$863,500 Materials Testing:$11,000 Miscellaneous (incl. printing)$500 Total for other costs:$11,500 Total Cost of Project $875,000 Project Account (90916) Available Funding:$682,100 Completed Projects (99899) Available Funding:$227,900 SEWERLINE REPLACEMENTS (90916) C8 - 2 ATTACHMENT C8 - 3 Page intentionally left blank. C8 - 4