Overview

A confidential client had several stretches of natural gas transmission pipeline in need of replacement. The pipeline sections were nearing their end of useful life and had begun to leak, becoming a safety concern. The high demand pipelines also needed to remain operable through construction. Additionally, the client had abandoned pipelines that were raising environmental concerns and needed to be removed.

Solution Details

Our role as prime engineer included: pipeline design, civil site design and engineering, engineering alignment sheets, purge and blowdown plan, estimate of construction costs, IFB and IFC sets, and as-built drawings and documentation. We re-designed 11,260 feet of existing faulty piping over 3 transmission pipelines. Three types of pipe were used in these projects, which included: 6-inch high density polyethylene (HDPE) SDR11 pipe, 10-inch FBE coated steel pipe, and 20-inch FBE coated steel pipe. Throughout the project, 6 tie-ins and one road crossing were also designed.

Due to the high demand, a temporary 2-inch bypass line was designed to circumvent a loss of service during maintenance. To service the lines, several new Right-of-way (ROWs) were established in addition to utilizing preexisting ROWs. The final stage of the project was to re-route a 4,686 foot stretch of pipeline. This section had been out of service for three years due to a surface mine expansion that resulted in a fractured line and an unusable route. The abandoned section was then removed.

With the pipeline successfully rehabilitated, the client can be confident in its safety and reliability for many years to come. They will also be free from any potential liabilities the abandoned pipeline presented.