Construction Practices

Pipeline Construction

Construction of a large transmission pipeline involves excavation of a trench, stockpiling of trench soils, segregation of topsoil, installation of pipe in the excavated trench, haul‐in of select backfill material, haul‐off of excess soil, compaction of trench material, final grading and restoration. These activities require a significant amount of heavy construction equipment, including multiple tracked backhoes, front‐end loaders, dump trucks, dozers, welding trucks and graders. Pipe laying is a linear operation and the pace of the construction depends, to a great extent, on the amount of available space in which to work. The ability to stockpile soils adjacent to the trench and the ability of equipment to traverse ahead of and behind the open trench, while staying within the work zone, mitigates impacts to adjacent roadways by minimizing the entries and exits. It also allows the construction to progress at a reasonable pace, reducing the time that adjacent facilities, roadways and the public are impacted by construction disturbance. Based on past similar large diameter transmission pipeline construction projects, the estimated width of construction activity to efficiently construct this pipeline is approximately 80‐100 feet.

Most of the pipeline route is adjacent to other linear facilities such as roads and existing easements. Available lands within these easements will be utilized for construction activities, thereby reducing the total width of permanent easement acquisition required. Where encountering features such as existing structures and wetlands, or when crossing creeks, this construction corridor has been reduced, for a short distance, to minimize impacts.

Reclamation Procedures

Northern Water works with individual property owners to develop a reclamation plan specific to the property’s needs. This may include specific seed mixes, watering requirements, pasture use, irrigation considerations, etc. The goal of the reclamation plan is to put the property back to its pre-existing condition or better.

These photos show locations where a pipeline is buried below grade in the area and the ground was revegetated. Following reclamation, the land where the pipeline is located can be utilized for farming operations, landscaping, etc., subject to easement requirements.