The Minnesota Public Utilities Commission has given the state commerce department 60 days to fill in gaps in its environmental assessment of Enbridge’s controversial Line 3 pipeline replacement project.

By a 4-1 vote, the PUC “essentially told the Commerce Department to rejigger three relatively small parts of the doorstop-sized EIS, and do so within 60 days,” the Star Tribune reports. “The PUC was reacting to criticisms of the EIS by Indian bands and environmental groups.”

“I am not looking to make a finding that the EIS is generally inadequate,” said PUC Commissioner Dan Lipschultz. “The EIS is quantitative, robust, and detailed,” but it needs to be “supplemented”.

Even so, “this is a big deal,” noted Youth Climate Intervenors, one of the community groups fighting the pipeline. “It’s not often that an EIS gets deemed inadequate, and the PUC went against Judge Lipman’s recommendation to make this decision. It adds more than two months to this rushed environmental review process—which means a stronger environmental review and more opportunity for public comment on the EIS.”

At the same time, the decision is “far from a perfect outcome,” YCI added. “The PUC decided that the vast majority of the EIS is fine, and only listed three very specific things that need to be fixed. The revised EIS will be an improvement, but it still leaves gaping holes (especially around long-term impacts and Indigenous rights).”

Pipeline opponents “have criticized the EIS on several fronts, including for the lack of a detailed assessment of a potential large oil spill into sensitive waters and wilderness areas,” the Star Tribune notes. They say the line “would expose a new region of Minnesota—including pristine lakes and wild rice waters—to degradation from oil spills.”

MN350 noted the PUC’s ruling also requires an ongoing study of tribal cultural properties to be “complete before Enbridge can start construction. We agree with many parties that this study should instead be finished before approvals are made, and with time for public input/engagement, but today’s decision represents progress.”

The PUC will decide in April whether the Line 3 replacement is needed, and if so, what route it should take. In September, the Department of Commerce stated that the 1960s-era line should be shut down, and that no replacement was needed. “This document will arouse considerable controversy,” Governor Mark Dayton told media at the time. “That discord should be recognized as part of the wisdom of the process.”