A citizen advisory group at the Minnesota Pollution Control Agency (MPCA) has collapsed following the regulator's decision to issue a water-quality permit to Enbridge Energy for its Line 3 oil pipeline cutting through Minnesota.

The bulk of the agency's Environmental Justice Advisory Group has resigned in protest over the permitting decision, saying in a letter Tuesday to MPCA Commissioner Laura Bishop that "we cannot continue to legitimize and provide cover for the MPCA's war on Black and brown people."

A dozen of the board's 17 members signed the letter, which called the water-quality permit the "final straw" in a series of MPCA actions that they said sidelined the advisory group. Among those resigning is Winona LaDuke, a member of the White Earth Band of Ojibwe and executive director of Honor the Earth who strongly opposes the pipeline.

In an interview, LaDuke called the decision "a slap in the face."

"The people who are most impacted are Indigenous people, and for seven years we have tried to make the system work," she said. "If the MPCA actually valued Indigenous people and environmental justice they would not have issued that permit."

LaDuke called her four years on the advisory group "a waste of time."

Commissioner Bishop issued a statement praising the board for making a "significant" difference at the state agency.

"I recognize the disappointment of some advisory group members regarding the Line 3 decision," Bishop said. "The MPCA will continue to eliminate and reverse environmental and health inequities and disparities in overburdened communities and ensure engagement remains at the forefront of our decisionmaking."

The environmental justice advisory group was created in 2016 by former MPCA Commissioner John Linc Stine, with unpaid members appointed by the commissioner. Many members work for advocacy groups or nonprofits. The group currently meets with the commissioner every other month for about 1 ½ hours, it said.

The state Public Utilities Commission is the primary regulator of pipelines in Minnesota, but last week the MPCA issued Enbridge a crucial permit for the project known as a "401 water quality certification." Denying such a permit could derail a project.

The certification takes its name from Section 401 of the country's Clean Water Act, and regulates pollutants discharged into nearby waters.

The $2.6 billion Line 3 oil pipeline would cut underground across northern Minnesota, crossing more than 200 streams, and affect more than 700 acres of wetlands as it carries oil from tar sands in Canada to Enbridge's terminal in Superior, Wis. The company says it needs the new pipeline to replace one that's worn.

Opponents say the project represents an unacceptable risk to the Native American tribes whose land and wild rice stands it crosses, and undermines the state's climate change goals to reduce greenhouse gas emissions from burning fossil fuels.

A number of groups challenged drafts of the water-quality permits last winter in a contested case hearing — including Friends of the Headwaters, Honor the Earth, the Sierra Club and the Red Lake and White Earth Ojibwe bands — but an administrative law judge sided with the MPCA. Meanwhile, three tribes are fighting the project in court for violating treaty rights.

The MPCA last week said the permit it issued to Enbridge was "its most stringent 401 water quality certification to date." It listed nearly three dozen conditions. For example, it prohibits releasing drilling mud into any water or wetlands, and bans construction in or near wild-rice waters or sensitive wetlands between April 1 and mid-July.

The permit does touch on pipeline operation. One condition says Enbridge must not discharge any crude oil from the pipeline into nearby waters, including groundwater, and that if it does it must immediately notify the state Department of Public Safety and MPCA, and clean it up.

Steve Morse, executive director of the Minnesota Environmental Partnership, said the MPCA took too narrow a view of its role in considering the 401 permit. He said the agency could have denied the permit on the grounds that construction alone of such a project would have caused unavoidable degradation to state waters.

The regulator is "constrained by historic business as usual," he said.

Staff writer Mike Hughlett contributed to this report.

Jennifer Bjorhus • 612-673-4683