Williams Partners LP and Southern Company Gas, a subsidiary of Southern Company, have successfully placed into service their Dalton Expansion Project, which was designed to add 448,000 Dth/d of capacity on the Transcontinental Gas Pipe Line Co. LLC (Transco) mainline running from New Jersey to Mississippi.

The project adds capacity to Transco’s mainline running from the Station 210 Zone 6 Pooling Point in Mercer County, NJ, to an interconnect with the Gulf South Pipeline Co. LP at Holmesville in Pike County, MS. The project also includes a lateral starting at Transco’s Compressor Station 115 in Coweta County, GA. The project was designed to deliver natural gas to an electric generating facility in northern Georgia operated by Atlanta Gas Light, and to the City of Cartersville, GA.

The project “is one of several Transco projects creating much-needed access to gas supplies in the northern portion of Transco’s system to meet growing demand in the South,” said Frank Ferazzi, senior vice president of Williams Partner’s Atlantic-Gulf operating area. “In addition to the environmental benefits of connecting electric power generators with this cleaner energy resource, these natural gas pipeline investments produce stable, long-term returns for our business.”

With the expansion, Transco’s system design capacity increased to 14.2 MMdt/d.

The Dalton Expansion received a Natural Gas Act certificate from FERC a year ago, and was approved to begin service in March [CP15-117]. The pipeline lateral is co-owned by Williams Partners and Southern Company Gas.

The opening of the Dalton Expansion caps a busy month for Transco across the South. The Federal Energy Regulatory Commission recently gave its approval for Transco to restore service on its Mainline A facilities in Prince William County, VA, as their replacement was nearly complete as part of the 1.7 Bcf/dAtlantic Sunrise project. The roughly $3 billion Atlantic Sunrise would open a path for constrained Marcellus Shale natural gas to reach markets in the Southeast through the Transco system.

In Florida, Williams last month placed into service the first phase of its Hillabee Expansion, adding 818,410 Dth/d of capacity in Alabama to the Transco system. The new capacity would be used to supply Transco Zone 4 gas to serve Florida power generators via the Sabal Trail Pipeline, which has been in service since mid-June.

And an environmental assessment of Transco’s Gulf Connector Project, a two-phase expansion of the Texas and Louisiana natural gas system, is scheduled to be issued Sept. 21, with federal authorizations due 90 days later, according FERC. The project would allow Transco to carry gas to South Texas via a proposed interconnection with Gulf South Pipeline Co. LP’s Coastal Bend Header in Wharton County, TX, and a proposed interconnection with Cheniere Pipeline in San Patricio County, TX.

Further north, some Transco expansion plans have hit roadblocks. Last month, the New York State Department of Environmental Conservation told Transco that its application for a water quality certification required by the federal Clean Water Act and other state permits for theNortheast Supply Enhancement Project was incomplete. The nearly $1 billion project would expand Transco to increase natural gas deliveries to National Grid, the largest distributor of natural gas in the Northeast.