AgdaPkt 2014-06-09 Closed and Joint SA

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7.1.D. - Page 1 REPORT To the Honorable Mayor and City Council From the City Manager June 9, 2014 SUBJECT Additional Construction Budget Request — Carson Reservoir Seismic Improvement Project RECOMMENDATION By motion, authorize the City Manager to increase the contract contingency amount from 10% up to 35%, as necessary to perform additional unforeseen essential repairs and complete the construction of this project. BACKGROUND On February 10, 2014 the City Council awarded the Contract for the Carson Reservoir Seismic Improvement project to the lowest responsible bidder, Anderson Pacific Engineering Construction Inc. of Santa Clara. Their bid was $579,210.00 and the approval authorized the City Manager to increase the contract amount up to 10% if necessary. Five bids were received at the bid opening on December 18, 2013. The low bid of $579,210.00 from Anderson Pacific Engineering Construction, Inc. was approximately $221,000.00 or 28% lower than the engineer's estimate of $800,000.00 for the cost of construction. The bid was also 26% lower than the average of the five bids. Work on the project started on April 3, 2014. The contractor completed 25% of the required work which focused mainly on mobilization, draining and cleaning the reservoir, lumber damage inspections, and installations of hurricane ties and reinforced nailing on existing roof rafters. Staff processed the first payment request for $150,700.00, and issued additional work change orders for $25,343.00 (4.4% of contract amount) to date. ANALYSIS The 82-year-old, 3.75 million gallon, concrete-lined Carson Reservoir is one of the oldest underground potable water storage reservoirs in the city. It is covered by a 61- year-old rectangular gravel roof that is one acre in size. To extend the useful life and improve the seismic performance of the reservoir the project will replace the damaged wood roof system lumber and repair damaged roof area. Structural modifications will be made to the roof system. Improvements also include installing water-sampling stations to monitor water quality, installing an access ladder, and replacement of the inlet pipe to improve water circulation within the reservoir. Necessary repairs to cracks within the reservoir will be made.