An open season announced last week by TransCanada Corp. on the eastern leg of its Mainline has prompted two other pipelines to jump on board with complementary eastbound Marcellus Shale-oriented projects of their own.

Iroquois Gas Transmission System LP and Portland Natural Gas Transmission System (PNGTS) on Tuesday each launched open seasons offering capacity intended to complement that being offered by TransCanada Corp. on the eastern leg of its Mainline (see Daily GPI,Dec. 2).

Iroquois isproposing a system reversal, called the South-to-North(SoNo) project, to provide access to TransCanada at Waddington, NY. Separately, PNGTS reopened a bindingopen season for its Continent 2 Coast (C2C) Expansion, which would expand capacity of its system from 168,000 Dth/d to about 300,000 Dth/d from Pittsburg, NH, to Westbrook, ME.

Iroquois is holding a nonbinding open season for SoNo, which would transport up to 300,000 Dth/d from Iroquois’ existing interconnects with Dominion Transmission in Canajoharie, NY, and Algonquin Gas Transmission in Brookfield, CT, as well as the proposed Constitution Pipeline in Wright, NY. With “minor modifications” Iroquois could achieve a November 2016 in-service date.

“Traditionally known as a north-to-south pipeline, we are excited to offer customers the ability to physically transport Marcellus Shale gas to the U.S.- Canada border,” said Scott Rupff , Iroquois vice president of marketing, development and commercial operations. “As our connectivity to competitively-priced Marcellus Shale supply continues to increase, Iroquois is well-positioned to deliver these new sources of supply to eastern Canadian and northern New England markets.”

Iroquois said SoNo and the PNGTS open season along with TransCanada’s “will provide markets in eastern Canada and northern New England with the opportunity to transport gas from Waddington and access Marcellus Shale volumes delivered into Iroquois.”

The Iroquois system runs 416 miles from the U.S.-Canada border at Waddington, NY, through Connecticut to South Commack, Long Island, NY and Hunts Point, Bronx, NY. SoNo bids will be accepted through Jan. 24. For information,

The PNGTS mainline consists of 144 miles of 24-inch diameter pipeline starting at an interconnect with TransCanada near Pittsburg, continuing to Westbrook and then on to Dracut, MA. The 30-inch diameter section of pipeline between Westbrook and Dracut is jointly owned with Maritimes & Northeast Pipeline and is contractually operated as two separate pipelines.

PNGTS said customers interested in C2C capacity may bid on any delivery point between Westbrook and Dracut, but additional capacity is only being contemplated between Pittsburg and Westbrook. Capacity along the jointly owned stretch of pipeline is to remain at 210,000 Dth/d. The PNGTS project is expected to be in service Nov. 1, 2016. PNGTS said it would consider capacity turnback offers from existing shippers for the project. The open season ends Jan. 24.