2015/11/25 Council Agenda Packet

t 4 ■ RFIs—as of August 1st there are 38 RFIs and BHC and the subconsultant team are projected to address 40 additional RFIs for the remainder of the project for a total of 78 RFIs. The Task Order 13 budget for BHC's effort was developed for 20 RFIs. ■ Meetings-Meetings through August occurred weekly instead of biweekly as budgeted. ■ Contractor guidance and claim response-several issues have required extensive contractor guidance and some have included drawing revisions,or contract change initiatives including the following: o Held special shoring/dewatering meeting on June 16,2015. o Provided a large number of submittal reviews for the shoring and dewatering systems proposed at LS33 including Submittals 8,8A,8B,4,4A,4B and 4C. Submittals are budgeted for two reviews,one initial and one resubmittal. The proposed shoring and dewatering systems required a greater number of reviews due to site challenges and quality of the submittals. o Relocated LS33 influent pipe—at the contractors request BHC revised the influent pipe alignment, changed pipe material to accommodate dewatering challenges and modified peat excavationlremoval requirements to accommodate pipe type. o Relocated LS43 at MSI's request to provide additional protection of nearby retaining wall and to accommodate contractors oversized shoring. o Addressed MSI's settlement question for pipes located in 36th street. o Addressed MSI/Axis's claim for additional compensation at LS33. • Geotechnical Support-Geotechnical issues at this challenging site have resulted in additional effort, including: o Increased submittal response effort: Based on the quality of McClure and Sons various geotechnical related submittals,BHC and HWA have had to spend considerably more time responding to submittals and contractor plans than anticipated. o Provided new earth pressure diagram for LS43 retaining wall. o Increased duration of sheet pile installation-HWA has had to spend more time dealing with temporary shoring issues that have come up due to MSI not following recommendations at LS43. In development of the scope and budget,HWA assumed the contractor would require approximately 5 full days to install the sheets for each lift station temporary shoring system. MSI and Axis Crane took longer than the anticipated duration to install the sheets. This hs required HWA to have their inspector on site for a greater amount of time than ant!cip..ated. For LS33,the increased time was largely due to encountering obstructions. The rate of production for LS43 was even worse than LS33 due to refuse and also due to MSI's use of sheet piles that went against HWA's recommendations for this location. o Completed additional resident engineer inspection-The City asked HWA to provide these services while Don Snyder was on vacation and when the contractor encountered more problems with the shoring installation at LS43. o Monitored deep dewatering well installation—The City asked HWA to monitor the installation of the contractor proposed dewatering wells at LS43 that extend down into the confined aquifer below. The purpose of HWA's monitoring was to confirm proper well installation and seal placement for the deep • • wells. If the wells are not installed properly,contamination at this location is possible because leachate from the landfill is perched above a relatively clean confined aquifer. Deep wells and other conduits that pass through the aquitard(hydraulic barrier above the confined aquifer)present a possible route for leachate to pass to the confined aquifer below. Shallow wells that do not reach the aquifer below do not pose this same contamination risk. HWA's efforts to observe the deep well installation were not part of the original Construction Services Scope,because only shallow wells were anticipated for contractors dewatering system. The deep wells were later proposed by the contractor during construction after the scope of work had been established. 21.E r7 20 October 2 P 2g. of S ciDrtcuL P,14f:_