Transcontinental Gas Pipe Line (Transco) is holding an open season for its Atlantic Sunrise project, which would provide between 450,000 and more than 1 million Dth/d of new, year-round firm transportation capacity by its proposed in-service date of July 1, 2017, the Williams subsidiary said in a notice posted Thursday. The open season is due to end Sept. 27.

The project would provide additional firm transportation capacity for growing supplies of natural gas from northern Pennsylvania along Transco’s existing Leidy Line to premium markets along the Transco pipeline system stretching from the northeastern United States in Transco’s Zone 6, to Zone 5 and terminating in Zone 4, according to the notice.

The primary firm transportation path would terminate at Transco’s existing Zone 4 point of interconnection between Transco’s mainline and Mobile Bay Lateral in Choctaw County, AL (the Zone 4 Pool), and Transco’s existing Zone 4A point of interconnection between Seller’s mainline and Mobile Bay Lateral on the Mobile Bay Lateral (the Zone 4A Pool).

Shippers may request receipt points on Transco’s Leidy Line located between the Grugan Interconnect in Clinton County, PA, and Transco’s Station 515 in Luzerne County, PA.

Details and application procedures are available on the Transco website or by calling Gary Duvall at (713) 215-2589.

The open season comes a year after Williams said shipper interest supported a portion of its Atlantic Access project, an expansion of the Leidy Line in northern Pennsylvania by up to 800,000 Dth/d, but the remainder of the project was shelved due to a lack of interest from shippers (see Shale Daily, Aug. 3, 2012). The resulting Leidy Southeast Expansion project would provide firm transportation from various supply points along Transco’s Leidy Line to delivery points terminating at its Zone 4 Market Pool in Alabama, along its mainline system. The project would increase the Transco pipeline’s capacity by 525,000 Dth/d of natural gas (enough to serve about 2 million homes). It would involve the construction of approximately 30 miles of additional looping, in Pennsylvania and New Jersey, in addition to modifying some existing pipeline facilities.

Last month Transco started service on the first pipeline loop of its major Northeast Supply Link expansion, one of the key links in sending new gas out of the Marcellus Shale (see Shale Daily, July 15). The project, when completed in its entirety later this year, is to provide incremental firm transportation service from the Marcellus to meet growing demand for gas in Pennsylvania, New Jersey and New York City. The Northeast Supply project is fully subscribed to four shippers: Williams Gas Marketing Inc. (135,000 Dth/d), Anadarko Energy Services (67,500 Dth/d), MMGS Inc. (32,500 Dth/d) and Hess Corp. (15,000 Dth/d).

More recently, Williams said it had restricted some natural gas pipeline services on Transco because of capacity constraints in the Pennsylvania portion of the Marcellus Shale (see Shale Daily, Aug. 2). A lack of infrastructure has hindered the pipeline, which has the capacity to carry 9.9 Bcf/d to markets across the Northeast and Southeast. However, Transco said it can’t accommodate gas transportation past the 195 station because receipts can’t exceed deliveries north of it.