Colorado Public Works Journal, Spring-Summer 2020

50 Colorado Public Works Journal Woodmoor Water and Sanitation Well 21 Project Sometimes in Public Works, the best solution to a challenge is neither the cheapest nor the easiest. However, these are the times when the opportunity to think out of the box, creates the unique solutions that drive our industry and our communities forward. The Woodmoor Well 21 is one of these projects. Water line instal- lations are generally routine and simple projects. In most cases we trench or horizontal drill a line through relatively flat terrain, with manageable soils. But what is your solution when the water line must run through hard sandstone, and has a significant change in elevation over a very short distance? This is the exact question that Woodmoor Water and Sanitation District asked when approaching the Well 21 project. During a recent lunch and learn event, sponsored by the Rocky Mountain section of the North American Society of Trenchless Technology, Woodmoor Water and Sanitation District put on dis- play their Well 21 Project, and shared with their experiences with creative solutions, a larger price tag, and good public perception. The Project Woodmoor Water and Sanitation relies on a number of Denver Basin wells to provide drinking water supply for the areas that it serves. As the population of the service area grows, Woodmoor drills new wells to increase the raw water supply available to meet the needs of its community. Well 21 is a new well in a residential area. The complete scope of the Well 21 project included drilling the well, constructing a pump house, and installing a raw water transmission line from the well to the main to their water treatment facility. The first phases of the project were relatively routine, drilling the well and constructing the pump house were completed with rela- tive ease and with few challenges. The water line portion of the project was not so simple. Well 21 sits at the top of a hill, with the treatment plant at the bottom. The most direct route for the line is through a narrow easement that is already filled with other utility lines, dense tree cover, and residential fences. Here in lies the challenge for Woodmoor. How do you trench for a water line through a narrow easement such as this? Jessie Shaffer, District Manager for Woodmoor Water and Sanita- tion explained during the RMNASTT site visit, that good public perception was important to this project, and that the board was concerned about the environmental impacts of the project. Using plans developed internally by the District with assistance from Lithos Engineering, Woodmoor put the project out to bid with three specific construction options: • Open cut the complete distance of the water line. • Open cut a small section, horizontal directional drill (HDD) the rest. • HDD a smaller section, open cut the majority of the line. Ariel Hacker, the District Engineer for Woodmoor explained that it was the Board’s decision to move forward with the larger HDD option. There was substantial concern from the Board regarding public perception and public impact, and in the end, this option, though more expensive had less visible impact to the community, reduced impacts to the environment, as well as a heightened assurance that the project completion date would be maintained, if not accelerated. The selected contractor for the project, Colorado Civil and Global Underground Corporation, proposed a project cost of $1.18 Mil- lion, nearly $300,000 more than the cost of trenching. Global Underground Corporation subcontracted with Dewberry and Brierley Associates to do a re-design of the horizontal directional drill, to accommodate the full scope of the almost 4,000 foot HDD. Value Engineering Value engineering is becoming more and more popular with municipal utility projects. It gives the contractor and the owner the ability to make changes in scope that will improve the quality of the project, while at the same time saving money. Benny Siljenberg, Vice President of Lithos Engineering, shared with the RMNASTT group that value engineering played an important part in streamlin- ing the Well 21 project, for both cost savings and time savings. The original project design called for splitting the directional drilling portion of the project into two smaller sections. However, mobilization costs under this option were higher and there was the by Tamara Moon Images © CPWJ