Enbridge had hoped this month to be building its controversial and much-delayed oil pipeline across northern Minnesota. Instead, the company may miss prime construction season for the second year in a row.
Minnesota pollution-control regulators are expected to announce this week whether to make a deeper inquiry into Enbridge's pipeline construction permits.
If they do — and that seems increasingly likely — Enbridge probably won't be able to start construction until late fall at best.

The $2.6 billion proposed pipeline, which is a replacement for its deteriorating Line 3, has been winding through the state's regulatory process for five years. The Minnesota Public Utilities Commission (PUC) reapproved the new Line 3 in early February.
The PUC is the primary regulator of oil pipelines in Minnesota, including determining the risk of oil-spill hazards once they are in operation. But Enbridge must also get more technical approvals from the Minnesota Pollution Control Agency (MPCA) and other agencies.
The MPCA in February released "draft permits" for the new Line 3 construction. In April, environmental groups and Ojibwe bands that oppose the new line petitioned the MPCA to conduct a "contested case" on the permits.
A contested case usually involves hearings and a review by an administrative law judge. Darin Broton, an MPCA spokesman, said Tuesday that the agency is still reviewing its decision, though he declined to disclose it.
"We are looking at the legal guidance set by the [Minnesota] Court of Appeals in the PolyMet case," he said. "The Court of Appeals made it clear that agencies don't have unfettered discretion to reject a contested case if issues of fact are unresolved."