A seven-year dispute has ended in an agreement by Trans Mountain Pipeline to reroute its expansion project by building a bypass around a native rights sore spot in southern British Columbia (BC).

The deal, filed late Friday with the Canada Energy Regulator (CER), charts the new course to avoid risking contamination of a subterranean aquifer tapped by the Coldwater Indian Band beneath its reserve near Merritt.

The detour would only lengthen the crude oil pipeline by 2.9 kilometers (1.7 miles) but requires 18.3 kilometers (11 miles) of new right-of-way. Engineering, construction, environmental and consultation plans for the change fill a 609-page CER filing.

Added costs were not disclosed. The total project estimate currently stands at C$12.6 billion ($9.4 billion) for nearly...