The construction of the pipeline is implementing a landmark American Indian water rights settlement for two tribes in western New Mexico and resolves a 25-year dispute over how much water the Navajo Nation should receive from the San Juan River.
This project was one of 14 high-priority infrastructure projects identified in 2012 by the Obama administration to benefit from an expedited permitting and environmental review process. Ultimately, the entire program features about 280 miles of pipeline, several pumping plants and two water treatment plants. When completed, the program will, for the first time, provide a long-term water supply to 203,000 people in Navajo communities 1,300 people in the Jicarilla Apache Nation, and 47,000 in the City of Gallup.
McMillen Jacob’s contract was to lay about 4 miles of 42-inch diameter water supply pipeline and appurtenant facilities about 8 miles north of Gallup in western New Mexico. Technical aspects of portions of the 4.25-mile pipeline included using hydraulic hammers to break apart and excavate portions of the pipe alignment where hard sandstone and claystone where found, utilizing 100% Navajo Nation workers to perform the work, navigating all the unmarked utilities in the right-of-way as well as coordinating work activities around the monsoon season which was prevalent in the area of the project. Installation of the 42-inch steel pipeline required excavation depths up to 20 feet as the pipeline crossed several county roads, existing buried utility lines, and numerous arroyos or washes on the site. A portable batch plant was also set up onsite to produce all the controlled low-strength material (CLSM) required for pipe embedment along the full 4.25-mile pipeline.
The pipeline was installed up two steep grades with slopes exceeding 80%. In addition to the technical aspects, there was the presence of numerous archeological sites within the project right-of-way. McMillen Jacobs coordinated all work activities with the archeological team onsite and adjusted the work activities as new sites were discovered during the removal of topsoil and excavation of the trench.
Key elements of this project include:
- Special precautions for existing infrastructure
- Coordination with federal and tribe reps and utilities
- Storm water management
- Large concrete pipe collars
- Corrosion monitoring/Cathodic Protection System
- Disinfection of 4 miles of water pipeline with over 1 million gallons of water