MINNEAPOLIS (AP) — The U.S. Army Corps of Engineers on Monday approved one of the last remaining permits for Enbridge Energy's planned Line 3 crude oil pipeline replacement across northern Minnesota, bringing the project a step closer to construction.

In a release from its St. Paul office, the Corps said it determined the Line 3 project “is compliant with all federal laws and regulations.”

“This decision is based on balancing development with protecting the environment,” said Col. Karl Jansen, commander of the St. Paul District commander.

“Our decision follows an exhaustive review of the application and the potential impacts associated with the construction of the pipeline within federally protected waters. Our staff worked deliberately and extensively with our federal and state partners, federally recognized Tribes, environmental organizations and the applicant. I believe our decision is based on sound science and strikes the balance between protecting natural resources and allowing reasonable development.”

All that remains in the six-year-old process now is for the Minnesota Pollution Control Agency to issue a storm water construction permit to protect surface waters from runoff while it's being built, and then for the independent Public Utilities Commission to give a final green light. The commission has already approved the project several times.

Pipeline opponents, including environmental and tribal groups, are still suing and protesting to try to block the project, and an appeal by the state Commerce Department is pending. But there are no injunctions in place to prevent Enbridge, based in Calgary, Alberta, from beginning construction if it gets final approval from the PUC.

Line 3 begins in Alberta and clips a corner of North Dakota before crossing Minnesota on its way to Enbridge's terminal in Superior, Wisconsin. Enbridge wants to replace the Minnesota section because it was built in the 1960s, and its increasing maintenance needs mean the company can run it at only half its original capacity. Replacement segments in Canada, North Dakota and Wisconsin are already operating.

Opponents say the pipeline threatens spills in pristine waters where Native Americans harvest wild rice and that the Canadian tar sands oil it would carry would aggravate climate change.

Enbridge says the $2.6 billion replacement will provide a safer way to transport the oil to Midwest refineries while creating 4,200 construction jobs and generating millions of dollars in local spending and tax revenues.

Democratic Gov. Tim Walz's administration has faced criticism from both sides over its handling of the project. Twelve of 17 members of an MPCA advisory group on environmental justice issues resigned after the agency approved a major water quality permit for the project Nov. 12. The Republican-controlled Minnesota Senate ousted Walz's commerce commissioner in September, after his agency appealed the PUC's most recent approval of the project. The department contends Enbridge failed to meet a statutory requirement for producing a legally adequate long-range oil demand forecast.