Mariner West Pipeline

Washington, Allegheny, and Beaver Counties, Pennsylvania

Mariner West Pipeline

Washington, Allegheny, and Beaver Counties, Pennsylvania

Project was to install a new 10” pipeline carrying Ethane from the Houston Plant to a point just south of the Ohio River located at the NOVA Chemicals property. This project was originally designed by two different consultants. Bowman was brought in to provide the engineering component. The project involved designing the valve nests and launchers/receivers for ethane.

Challenges to this project included designing the HDDs due to in-sufficient right-of-way (ROW) and PIs too close the drill sites. We resolved these challenges by working with the client’s land and permitting teams to develop an optimal design within the right-of-way constraints, resulting in timely project completion for the owner.

The ROW also included a 20” HP gas pipeline which had to be included in the HDD and bore profiles. This added a layer of complexity to the project by requiring additional right-of-way for drills, pull back room for pipe and tree clearing. These additional requirements were cause for several issues with landowners and Indiana Bat habitats in the area. We resolved these issues by designing drill paths with multiple mid-welds and recommending the use of specialized drills.

Challenges were also encountered at the Rt 18 crossing where, due to a very steep slope, the ROW began to slide causing dangerous conditions. To address this condition, Bowman provided geotechnical consultation to mitigate the slope stability issues, resulting in safe working conditions and a safe, reliable pipeline for the owner.

During the process, a 36” Transite water main was discovered along the route at the NOVA Plant. This water main was critical to the plant’s operations and was in very poor condition. Bowman safely and effectively designed a solution that ensured the plant to remain operational by negotiating with NOVA Chemicals. This resulted in designing an above-ground solution that minimized impact to the water main.

The original EFRD Report and Plume Study were revised to evaluate the efficacy of the valve station locations. Multiple wetlands, roads and creeks were designed to cross using HDD or conventional bore methods. Project involved one HDD under Wheeling & Lake Erie Railroad and one HDD under Raccoon Creek.

Bowman also assisted in developing the commissioning procedure for the ethane pipeline. This project included T&E Species restriction for Indiana Bat.