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SR 12-06-2016 3K Ci ty Council Report City Council Meeting : December 6, 2016 Agenda Item: 3.K 1 of 3 To: Mayor and City Council From: Susan Cline, Director , Public Works, Water Resources Subject: City Services Building Well Construction Contract Change Order Recommended Action Staff recommends that the City Council authorize the City Manager to negotia te and execute a first modification to A greement #10336 (CCS) in the amount of $15,55 4 with BC 2 Environmental, a California -based company, for additional construction services on the City Services Building exploratory boring and water supply drilling proje ct . This will result in a n amended agreement with a new total amount not to exceed $284,59 1 . Executive Summary On July 12, 2016 (Attachment A), Council authorized the City to enter into a construction contract with BC 2 Environmental to drill a 650 foot d eep exploratory well on the west side of City Hall to evaluate regional geology and to potentially install a groundwater supply well for the new City Services Building (CSB) in an amount not to exceed $269,037. Due to construction noise concerns expressed by the community, sound abatement panels were deployed. Further, additional pumping to obtain necessary water samples and disposal of sediment generated by testing activities was also required . Staff recommends that Council authorize the City Manager to e xecute a first modification to construction contract #10336 (CCS) for $15,55 4 with an amended new total amount not to exceed $284,59 1 . Background Drilling for this project commenced on September 20, 2016. A primary objective of this project was to drill and obtain hydrogeologic data from a deep exploratory boring which would be used to assess the quantity and quality of the City’s groundwater resources in this portion of the Coastal sub basin. A secondary objective of the project was to construct a shall ow, small -diameter potable -supply water well to support the proposed City Services Building (CSB ). Once tested and permitted, groundwater from the well w ould be treated and utilized as a supplemental onsite water source for the CSB. The design of the pota ble well w ould be based on the hydrogeologic data obtained from the exploratory boring. 2 of 3 The proposed deep exploratory boring was drilled using standard water well drilling methods to collect samples, evaluate the subsurface geology, and obtain geophysical logging data from the borehole. A critical piece of data the City obtained was the confirmation of fresh groundwater in the subsurface at this location and the depth to the subsurface interface between fresh groundwater water and saline groundwater. A d irect benefit of this data is that it supports the City’s strategic planning for long -term water self -sufficiency. The well wa s completed on October 20, 2016. Discussion This project was procured utilizing the City’s competitive bid process. On April 14, 2016, the City published Notices Inviting Bids to furnish and provide drilling and well construction work in accordance with City specifications. The bid was posted on the City’s on -line bidding site, and notices were advertised in the Santa Monica Daily P ress in accordance with City Charter and Municipal Code provisions. The City received five proposals. BC 2 Environmental was selected based on, among other things, price and experience. Due to construction noise concerns expressed by the community, optiona l sound abatement panels were deployed at the project site during drilling. Additional pumping was also required to obtain necessary groundwater quality samples because of the high clay content in the subsurface at the drilling location . In addition, the clay sediment needed to be vacuumed from the bottom of the onsite Baker storage tanks to provide storage space for development water from the well. The unforeseen additional contractor time and high clay content at the drilling site resulted in change or der costs exceeding the 10% contingency for this project. Two groundwater bearing zones were identified for potential use. The project is now complete. Financial Impacts and Budget Actions The contract modification to be awarded to BC 2 Environmental is $15,55 4 , for an amended contract total not to exceed $284,59 1 . Funds are available in the FY 2016 -17 Capital Improvement Program budget in account C019 0 45.589000. 3 of 3 Prepared By: Thomas Watson, Water Resources Protection Programs Coordinator Approved Forw arded to Council Attachments: A. July 12, 2016 Staff Report - Award Design and Construction Contract for City Services Building Well Reference:    Modify  Agreement  No. 10336    (CCS)