After a three-year permitting process, Williams Partners LP said Monday that Transcontinental Gas Pipe Line Co. LLC (Transco) has officially started greenfield construction on the Atlantic Sunrise project, which is expected to last 10 months.

Contractors broke ground on Friday in Wyoming and Columbia counties, PA, where they’re working on two new compressor stations. The project would expand the Transco system to deliver natural gas from Northeast Pennsylvania to the Mid-Atlantic and Southeast. Construction started last spring on the mainline portion and some capacity is already in service.

The company has to install more than 180 miles of pipeline. The project would cross 10 counties in Pennsylvania. Pipeline construction is expected to start next week in eight counties in the state, most of which is planned to occur at the same time.

Williams started the pre-filing process at FERC in early 2014 for the nearly $3 billion project and applied for a certificate in March 2015. The Federal Energy Regulatory Commission approved the expansion in February and the Pennsylvania Department of Environmental Protection issued the last of the major state permits last month.

The company made modifications to more than half of the original pipeline route. It has also worked with local stakeholders to provide $2.5 million for conservation projects in the expansion area. The project would provide 1.7 Bcf/d of much needed takeaway capacity for shale gas producers in Northeast Pennsylvania. Cabot Oil & Gas Corp. (1 Bcf/d), Chief Oil & Gas LLC (420 MMcf/d) and Seneca Resources Corp. (190 MMcf/d) have contracted for the highest volumes.

FERC cleared the entire project to start construction on Friday. It is expected to be fully operational by mid-2018. During peak construction periods, Atlantic Sunrise is projected to employ 2,300 people, according to researchers at the Pennsylvania State University.