2015 Issue

47 CONSTRUCTION MANAGER/GENERAL CONTRACTOR PROJ- ECT DELIVERY Because of the difficulty associated with construction of a large di- ameter pipeline located in residential streets, the increased leakage that was occurring on the existing pipeline, and the desire to ac- celerate the design and construction schedule the District and their design engineer, selected an integrated team approach to deliver the project by using a Construction Manager/General Contractor (CMGC) project delivery method. This allowed the Contractor to provide input during design, and suggestions related to design, cost, schedule, and constructability issues. The project schedule was structured to allowmultiple design activi- ties to occur concurrently and keep the project moving forward at an efficient and accelerated pace. The contractual arrangement and benefits of the CMGC project delivery are discussed below. Contractual Arrangement Once the District was ready to move forward with the design of a new pipeline on a parallel alignment they hired a design engineer to prepare the final design and contract documents for the project. They also asked that the design engineer support the District with the procurement of a contractor to provide CMGC services dur- ing design which also included the option to move forward into construction if the pricing of the project was favorable. Figure 7 below shows the contractual arrangement between the Owner, Engineer, and Contractor. Figure 7. Contractual Arrangement of CMGC Project Delivery Method Using the CMGC delivery process, the District was able to select a contractor during the design phase based on qualifications and best value. The CMGC was asked to provide design reviews at the 30, 60, and 90 percent design phases along with cost estimates at the 30 and 60 percent phase. At the 90 percent phase the CMGC was asked to provide an open book Guaranteed Maximum Price (GMP) so the District could determine if it was competitively priced. If the price was determined to be competitive then the District would move forward with a contract for construction. If the price was not competitive then theDistrict reserved the right to terminate the CMGC contract and competitively bid the project similar to a traditional design – bid – build project. Benefits of CMGC Project Delivery Having a knowledgeable and experienced contractor on board during the design process proved to be very valuable. For a tradi- tional design-bid-build project the design engineer cannot always predict the contractor’s construction methods, plans for staging of equipment and material, proposed backfill material that will be used, plans for dealing with traffic control and surface restoration (paving), and many other items that cannot be established until the construction phase. With the CMGC delivery process many of these unknowns can be established during the design phase and gain endorsement from the owner and jurisdictional agencies. A description of many of these items are summarized below. Early and Consistent Public Involvement Team. The CMGC delivery method allowed the engagement of a public involvement team that started during the design phase and carried through construction. As part of the predesign phase the contractor was required to provide a public involvement firm that assisted the District and Design Engineer with several communication efforts including newsletters, brochures, public open house meetings, and one on one communication with affected residents. With the construction occurring in residential streets, the District knew that strong communications between project participants would be necessary for successful completion of the project. Being able to start the public involvement effort early prepared the community for the construction impact well in advance of any actual construction taking place. It also allowed the contractor to better understand project constraints such as coordination with school bus routes and residents requiring special needs. During construction, the CMGC provided a full-time public involve- ment program that included a 24-hour hotline and a project website where residents can receive important announcements, viewdetour routes, and track progress of the construction. Utility Investigations and Relocations. During the design phase the contrac- tor assisted the design en- gineer with utility investi- gations by potholing and uncovering existing utilities. This allowed the contractor to have first-hand knowl- edge of the location of key utility crossings, better understand soil conditions that could be expected during trench excavation, and pavement conditions of the existing roadways. As part of the potholing and geotechnical investigations completed during the design phase, existing utilities on the pipeline alignment were marked in the field by utility locating crews. This provided the opportunity for the design engineer and contractor tomeet in the field and discuss approaches to utility relocations and installing the pipeline at heavily congested utility crossings and intersections. Installing a large diameter pipeline in residential streets often requires utilities to be relocated and there aremultiple pipeline alignments that can be selected depending on the utilities considered for relocation. Gaining agreement during the design phase between the contractor and engineer on approaches to dealing with existing utilities proved to be very valuable. Figure 8. 36-inch Pipe Installation Near Residential Homes CULINARY PIPELINE | continued on page 48