As part of Mariner East 2, Sunoco Pipeline identified ways to minimize environmental impacts to wetlands, waterways, wildlife habitats and other sensitive areas, and horizontal directional drilling offered the best construction method to do this. The use of drills well below the surface will reduce the total wetland area impacted by construction from 118 acres to 36. Less than half an acre of wetlands, the approximate size of an NHL hockey rink, will be permanently converted from its original state. HDD allows the pipeline to bypass culturally sensitive areas and avoid traffic disruption, and it further protects the pipeline from third-party damage.

At the same time, horizontal drilling is sometimes accompanied by inadvertent returns of drilling mud, which is made of drinking water and non-toxic bentonite clay. Any ingredients in the drilling fluid must be approved by the DEP and meet safe drinking water standards, and that is specifically in case the fluid escapes through a seem in the geology and into the environment. As part of our permits with the DEP, we have plans to monitor for inadvertent returns, contain any bentonite and water, and recover it.

While we have experienced inadvertent returns in a number of drills, this is not unexpected as the permit applications submitted and approved by the DEP include, among other requirements, compliance with an Inadvertent Return Contingency Plan, which we have followed by responding and containing those returns to avoid any long-term impacts and reporting them to the DEP. We have worked in coordination with the DEP to ensure that the environment is protected and will continue to do so.