Sunoco Pipeline has been ordered to suspend the work associated with the $2.5bn Mariner East 2 pipeline by the Pennsylvania Department of Environmental Protection (DEP), after finding construction permit violations.

The DEP directed the firm to cease all pipeline project construction activity, except for maintenance of erosion controls and limited maintenance of horizontal directional drilling equipment.

DEP said that the permits will be suspended until the company meets all the terms outlined in the order including addressing all impacts to private water wells in Silver Spring Township, Cumberland County.

Sunoco is also required to identify all in-progress or future construction activities as well as detail the specific Chapter 102 and Chapter 105 permit under which the activity is approved.

Additionally, the firm must submit a Operations Plan which would include a detailed additional measures and controls to reduce inadvertent returns.

DEP Secretary Patrick McDonnell said: “Until Sunoco can demonstrate that the permit conditions can and will be followed, DEP has no alternative but to suspend the permits,”

“We are living up to our promise to hold this project accountable to the strong protections in the permits.”

The Mariner East 2 project is part of Sunoco’s Mariner East project, which is expected to provide a combined 345,000 barrels per day of NGL capacity from the shale regions. While the Mariner East 1 project has capacity of 70,000 barrels per day, the Mariner East 2 project is designed to have an initial capacity of 275,000 barrels per day of natural gas liquids (NGLs).

The Mariner East 2 project is intended to deliver NGLs from the liquid-rich shale areas in Western Pennsylvania, West Virginia and Eastern Ohio to Sunoco’s Marcus Hook Industrial Complex on the Delaware River in Pennsylvania.

At the complex, the NGLs will be stored and distributed to various local, domestic and international markets.