The Minnesota Public Utilities Commission (MPUC) has tentatively approved plans by Calgary-based Enbridge Energy Partners LP to replace a crude oil pipeline across the state's northern tier.

MPUC plans to hold hearings on petitions for reconsidering the Line 3 project, which calls for replacing pipeline built in the 1960s. Line 3 carries Canadian crude from Alberta through North Dakota and Minnesota to Enbridge's terminal in Superior, WI.

Opponents of the project, including the Sierra Club, filed petitions for reconsidering MPUC's order last month that granted a certificate of need. If the regulatory agency denies petitions to reconsider, opponents may appeal to the Minnesota Court of Appeals. Enbridge urged MPUC to reject the petitions earlier in October.

Last August, Enbridge management said it expects to complete the replacement by the second half of 2019. The firm reached an agreement with the Fond du Lac Band of Lake Superior Chippewa in September. The agreement for the pipeline, which traverses the band's reservation in northeast Minnesota, gave Enbridge easements for six existing oil pipelines through 2039.

Enbridge reported in August that construction was 40% complete on the Canadian portion of the replacement project, measuring 1,660 kilometers (1,031 miles) and at a cost of C$5.3 billion ($4.2 billion). Work is scheduled to begin early next year on the $2.9 billion Minnesota pipeline.

The Line 3 replacement would allow a 370,000 b/d gain in export capacity from the Alberta oilsands. The replacement pipeline would restore deliveries to the original level of 760,000 b/d, after running at about half-capacity since 2010 because of safety restrictions.