Enbridge Energy Partners LP urged regulators with the Minnesota Public Utilities Commission (MPUC) to reject calls for it to reconsider its authorization of a crude oil pipeline replacement project across the state’s northern tier.

Calgary-based Enbridge has proposed replacing Line 3, which was built in the 1960s and carries Canadian crude from Alberta through North Dakota and Minnesota to its terminal in Superior, WI. But opponents of the project, including the Sierra Club, filed petitions for reconsideration of the order since MPUC issued an order granting certificate of need last month.

“The commission’s decision to grant a certificate of need for the Line 3 replacement project fully complies with the law, is consistent with decades of commission precedent, and is supported by the voluminous record developed over the past four years,” Enbridge said in a filing last week. “Therefore, the commission should deny the requests.”

Enbridge disputed assertions by the project’s opponents that it didn’t submit a forecasted demand for crude oil to MPUC, or that regulators failed to consider viable alternatives.

Last August, Enbridge told stockholders that it hopes to complete the Line 3 replacement by the second half of 2019. The firm reached an agreement with the Fond du Lac Band of Lake Superior Chippewa over the project in September. The pipeline traverses the band’s reservation in northeast Minnesota. Financial terms were not disclosed. The agreement 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 part of the project.

The Line 3 replacement is a 370,000 b/d gain in export capacity for 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.