Minnesota pollution regulators will do a deeper inquiry into Enbridge's permit applications for its controversial new oil pipeline, a move that would push back most construction until 2021.
The Minnesota Pollution Control Agency (MPCA) said Wednesday it will conduct a "contested case" hearing on a "401" water permit needed for the $2.6 billion project, which would replace Enbridge's deteriorating Line 3.
The hearing, to be scheduled later this summer, will focus on Enbridge's pipeline construction at water crossings and on wetlands.
"The MPCA is committed to ensuring its 401 water quality certification provides robust and comprehensive protections to Minnesota's waters and that the agency follows all permitting requirements under the law," the agency's commissioner, Laura Bishop, said in a statement.

The MPCA had an Aug. 15 deadline to decide on water-quality permits for construction of the 340-mile pipeline across northern Minnesota. That deadline will be moved to Nov. 14 because of the "contested" status.
Enbridge said Wednesday it expects the majority of the new Line 3 in Minnesota to be built next year, missing the summer construction season for the second consecutive year.
"While the contested case has caused a delay to the permitting process, we believe this additional step will strengthen the MPCA's decision record," said Vern Yu, Enbridge's president of liquid pipelines, in a statement.
The Minnesota Public Utilities Commission (PUC) is the primary regulator of oil pipelines in Minnesota, including determining the risk of oil-spill hazards. The PUC reapproved Line 3 in February after an appeals court kicked it back to the panel.