Using CMAR Contracts for HDD Projects

Construction Manager at Risk (CMAR) contract mechanisms have been used for decades in other types of construction around the world. CMAR contracts are a relatively new concept in horizontal-directional drilling projects, but this type of construction with a high risk is suited for this type of contract instrument. This paper will cover the Bartram/US1 24″ Water Main project that consisted of three HDPE horizontal directional drills: one across I-95, one across Durbin Creek, and one across wetlands. The purpose of this project was to provide a dedicated fill line to the Bartram Repump Station. The current water supply source was also used as a distribution main for the surrounding area. When the station is filling, the existing main could not meet the demands of the surrounding area, which results in low water pressures within the grid. As development continues in the area, the duration of low water pressures would have continued to increase, further decreasing system reliability without this new 24″ water main. This required the line to be put in across a high-risk corridor utilizing three horizontal directional drills quickly before more low-pressure events happen and to meet the growth in the area. It was decided to use the CMAR with guaranteed maximum price (GMP) contract mechanism to shorten the procurement time for the construction contractor and to reduce the risks of the HDDs across sensitive infrastructure and waterways. An overview of the project phases with CMAR procurement and collaboration will be covered, as well as risk register development, GMP negotiations, project cost auditing, and final schedule and cost analysis.