Request for Council Action
Total Page：16
File Type：pdf, Size：1020Kb
REQUEST FOR COUNCIL ACTION Date: 4/26/10 Item No.: 12.c Department Approval Acting City Manager Approval Item Description: Amend Contract for the Design of the Twin Lakes AUAR Subarea I Infrastructure Improvements 1 BACKGROUND 2 On June 9, 2008, the City Council approved a contract with WSB & Associates to complete the design 3 work for the Twin Lakes AUAR Subarea I Infrastructure Improvements. These include: 4 • Intersection improvements at County Road C and Cleveland Avenue 5 • Cleveland Ave / I35W ramp and intersection improvements 6 • Intersection improvements at Fairview and Terrace Drive 7 • Twin Lakes Parkway from Cleveland Ave. to Fairview Ave 8 • Mount Ridge Road from County Road C2 to Twin Lakes Parkway 9 • Prior Avenue south of Twin Lakes Parkway to County Road C 10 • Municipal utilities including sanitary sewer, water, and storm water. 11 This contract is attached, the executed contract does not have line numbers for reference so we have 12 attached a copy with line numbers. There have been many changes to the original RFP scope. While 13 the original contract contained “not to exceed” cost of $458,036.00, the additional work outside of the 14 scope of the contract added to the project work plan, increasing the cost for completing the design of 15 this infrastructure. What follows is a summary of the justification for the change in scope of this 16 project. 17 Project Phasing 18 The original scope of services assumed that these projects would be bid as a single construction 19 package. Much of the change in approach from a single project to a multi phase project occurred after 20 the plans were at the 60% level. These items increased the overall cost to provide these services by 21 $18,798. This created the following additional work: 22 • Temporary Twin Lakes Approach – When switching from full plans to Phase 1 plans, the City 23 directed WSB to design part of Twin Lakes Parkway for temporary connection to Cleveland 24 Avenue rather than the full width, as the Cleveland Avenue and I-35 ramp improvements were 25 not being built. WSB was also directed to avoid demolition of the building to the south 26 (Cummins building) if possible. WSB designed as directed, but noted the difficult grades 27 adjacent to the building. Through right of way negotiations, the City determined that it was more 28 economical to have the building removed as part of Phase 1, and directed WSB to add the 29 building removal back into the plans, and revised the road plans in this area to include the full 30 width and sidewalk for the majority of the formerly temporary area. 31 • Financial Phasing – At the 60 percent level, the City directed WSB to divide the full project into 32 logical portions and prepare a corresponding cost estimate in order to make decisions regarding Page 1 of 4 33 the scope of Phase 1. The City used this information to correlate the limit of the Phase 1 34 improvements with their corresponding funding. WSB coordinated the logical division points 35 with the City, prepared an exhibit to graphically depict the different segments, and split the 36 quantities for the entire project to correspond to these limits. 37 • Alternate Bid Items – To accommodate funding concerns, the City directed WSB and Hoisington 38 Koegler to establish five alternate bid items for the contract. These items included building 39 removal (in case the owners could get better prices), concrete pavers (alternate to colored 40 textured concrete), rain gardens along Mount Ridge Road (base bid was just a sodded area), 41 induction lighting (alternate to conventional lighting in base bid), and remote telemetry 42 (SCADA) system. WSB and HKGi prepared modified plan sheets, alternate and extra 43 specifications, performed product research, and modified the bid documents to accommodate 44 these requests. 45 • Bidding – Bidding services were not included in the original scope of work. At the time of the 46 original RFP, the City anticipated that WSB would complete the development of plans and 47 specifications only. In 2008, the City did not have funding available to construct the 48 infrastructure improvements. WSB handled the bidding process, including questions from 49 bidders and issuing of addenda. The inclusion of the storm water reuse system and associated 50 filtration beds made this more time consuming than a typical level of effort for both answering 51 questions and issuing addenda. 52 • Federal Funding- $1.6 million dollars of Federal UPA funding was provided by Metro Transit to 53 construct Phase 1 of this project. Due to the use of UPA money, the specifications had to 54 include several additional requirements, mostly for DBE requirements. WSB needed to 55 coordinate with Metro Transit personnel, obtained electronic copies of their forms, and reviewed 56 and redlined them for inclusion into the project manual. 57 Comprehensive Storm Water Plan 58 The original scope assumed that much of the water treatment for these public improvements would be 59 accomplished in concert with redevelopment. WSB was responsible for After submittal of 60 percent 60 plans with drainage treatment ponds shown on redevelopment parcels, it was determined that the effort 61 to coordinate a master drainage plan with the use of ponds (and obtaining the additional right of way) 62 would increase the right of way acquisition cost, as well as create potential future obstacles for the 63 property owners to redevelop their sites in accordance with the Twin Lakes design principles. At that 64 time, the City directed WSB to design a storm treatment system that would be located entirely within the 65 boundaries of the right of way that was being acquired for the project. This included a storm water 66 reuse system, complete with underground retention and storage, as well as a force main for conveyance 67 of the storm water to the irrigation system. These items increased the overall cost to provide these 68 services by $81,733. The following tasks were required to complete the final design of the system. 69 Many of these tasks were not contemplated as part of the original proposal, and required the redesign of 70 the storm sewer conveyance system. 71 • Changes in the Storm Water Conveyance System– The original conveyance system directed 72 storm water to a series of ponds throughout the project. Per the City’s direction, all the storm 73 water was now to be directed to a central location for storage. WSB reworked the conveyance 74 system to direct water to the future remnant parcel at the northeast corner of the roundabout. 75 However, through development of the MPCA Response Action Plan, it was determined that this 76 location would not be feasible due to high potential for contaminated soils. Thus, WSB had to 77 design the conveyance system a third time, resulting in two systems – one that drained as much 78 as possible to the new storage location at the north end, and the rest toward Cleveland Avenue. Page 2 of 4 79 This meant redoing spread-runby calculations, modifying catch basin layouts, realigning pipes, 80 adjusting pipe grades, and deleting/adding pipe profiles to the plans. 81 • Storm Water Storage, Reuse, and Infiltration System – Custom design of the storage, reuse, and 82 infiltration system was required. Activities included research of available systems and materials; 83 coordination with potential suppliers to provide a wide variety of alternatives for consideration; 84 schematic design of the system to meet requirements for seasonal considerations, infiltration 85 rates and volumes, storage versus reuse rates, and maintenance access; introduction of lift station 86 and well system design expertise for returning the water to the irrigation system; design of the 87 storm water force main; coordination with and design by an electrical subconsultant to design the 88 power. 89 • Additional Rice Creek Watershed District (RCWD) Coordination– WSB had anticipated 90 coordination with Rice Creek to accommodate traditional approaches to drainage treatment. 91 Because of the custom and unique nature of this system, additional correspondence, negotiation, 92 and discussions with the District were required to establish proper credit and permitting for the 93 new system. Additional time was also spent to resolve interagency coordination between the 94 Minnesota Pollution Control Agency and RCWD. 95 • Biofiltration Beds – Original landscape design for the areas along Twin Lakes Parkway called 96 for planting beds. At the direction of the City, Hoisington Koegler Group and WSB investigated 97 direct application of storm water to these bids, converting them to biofiltration beds. Additional 98 plant types were researched and specified, special soil design to aid infiltration was performed, 99 special direct inlets were designed, tile drain systems were researched and specified, weir 100 systems were designed, specified and detailed for drainage and aesthetic improvements, and 101 overflow/safeguard systems were calculated and designed. 102 Additional Services Phase 2 and 3 103 • Schedule and Budget Tracking / Invoicing: With the additional time added to the schedule of 104 the contract, the project manager must perform additional monthly budget and schedule tracking. 105 The duration of Phase 2 & 3 design is expected to be three months. 106 • Design Review Meetings: Three additional design review meetings are anticipated for Phase 2 107 & 3 (one per month). 108 • Biofiltration Beds: Much of the design detail from the biofiltration beds can be carried forward 109 as a template for Phase 2. However, each bed is custom designed to match road grade, width, 110 length, and sidewalk offset. The proposed hours accommodates these custom calculations and 111 design. 112 • Lift Station Design – Phase 3: In order to ensure to meet Rice Creek Watershed District 113 requirements for Phase 3, it is anticipated that a combination of pond expansion and use of the 114 existing irrigation reuse/infiltration system (installed in Phase 1) will need to be utilized.