Dominion Transmission (DTI) on Monday estimated North-to-South capacity for nominations on its system for Feb. 1 at 850,000 Dth/d. The volume may be adjusted “on a daily or periodic basis as required by operational conditions,” the company said in an informational posting.

The announcement came just days after DTI said a surge of natural gas from the Marcellus Shale and the demands of this month’s frigid weather across its footprint would force it to limit north-south nominations (see Daily GPI, Jan. 24).

Historically, supplies received in the north have benefited DTI operations, company officials said during a winter operations update conference call Wednesday. But “extreme volumes” in the north, particularly from the Marcellus, combined with a reduction in physical supplies in the south, are “impacting our ability to manage the loads, to balance the markets between the north and the south, and could potentially jeopardize our ability to fill our firm requirements and particularly stress out our storage system,” said Joe Kienle, DTI’s director of systems planning.

The recent polar vortex underscored the need for such limits, the company said. Jan. 6-8 was the coldest period in DTI’s market area since early 1994, forcing restrictions in Ohio and Central markets for the first time in the company’s operating history. And voluntary responses during the cold snap “fell far short of DTI’s receipt requirements at southern interconnects,” the company said.