Williams Partners LP (NYSE: WPZ) said that construction is nearing completion on the Atlantic Sunrise pipeline project—a critical expansion of the existing Transco natural gas pipeline to connect abundant Marcellus gas supplies with markets in the Mid-Atlantic and Southeastern U.S.

The project sponsors report that the project is targeted for mechanical completion beginning in August, with full service at about 1.7 Bcf/d anticipated to commence in the second half of the month, assuming timely receipt of the remaining regulatory approvals. A portion of the mainline component of the project of about 550 MMcf/d has already been placed into service.

The mechanical completion date is based upon current contractor schedules and may be affected by weather.

Greenfield construction on the Pennsylvania portion of the project began in September 2017. The project has featured the installation of about 200 miles of large diameter pipeline, two greenfield compressor stations and compressor station modifications in five states. The segment of the project known as the Central Penn Line will be jointly owned by Transco and a third party.

The Federal Energy Regulatory Commission (FERC) authorized the project in February 2017, concluding that environmental impacts associated with the project would be reduced to “less than significant levels” with the implementation of mitigation measures proposed by the company and FERC.