Sunoco Logistics is digging away on its Mariner East 2 pipeline — a project that will quadruple the volume of natural gas liquids flowing across Pennsylvania once the company navigates more than 2,000 streams, wetlands, roads and railways between Western Pennsylvania and the Philadelphia area.

The company says it expects no problems through construction and beyond, though environmental groups across the state fear the worst.

Mariner East 2 will cross 36 miles and 270 properties in Westmoreland County; none of the approximately 250 oil and gas companies with production in the county are currently laying pipeline, according to the DEP.

About 580 miles of existing pipelines form an underground spider web across the county. Those include gas transmission and hazardous liquid lines, according to National Pipeline Mapping System data.

Pennsylvania has more than 12,000 miles of large-diameter oil and gas pipelines, with the miles of natural-gas gathering lines expected to at least quadruple by 2030, according to a February 2016 report from the Governor's Pipeline Infrastructure Task Force.

The Mariner East project of Philadelphia-based Sunoco Logistics carries natural gas liquids from Marcellus and Utica shale gas wells in Western Pennsylvania, Ohio and West Virginia to the company's Marcus Hook Industrial Complex in Delaware County, where it is processed, stored and distributed to market.

To traverse the 306 miles from the border with the West Virginia panhandle to the facility outside Philadelphia, crews installing the Mariner East 2 will cross roughly 750 streams, 575 wetlands, 670 roads and 25 railroads.

Sunoco Logistics plans to use horizontal and conventional bore drilling methods extensively for the Mariner East 2 pipeline to reduce environmental impacts.

According to the Pipeline and Hazardous Materials Safety Administration, a branch of the U.S. Department of Transportation, Sunoco Logistics has had 279 incidents since 2007. A high of 36 occurred in 2013.

Sunoco reported four pipeline leaks in Pennsylvania since 2011. None was related to natural gas liquid lines.

Source: Trib Live The Tribune-Review PA