SIOUX FALLS, S.D. (AP) — The operator of the long-delayed Keystone XL crude oil pipeline on Monday formally asked South Dakota’s utility regulators to recertify the portion of the project that runs through the state.

The Public Utilities Commission must recertify that the conditions for construction of that portion of the pipeline haven’t changed since the permits were first issued in 2010. State rules dictate permits must be reapproved if the construction of the project does not start within four years of their issuance.