The B.C. government has filed to register as an intervenor in the National Energy Board's reconsideration of aspects of the Trans Mountain pipeline expansion.

But Environment Minister George Heyman questions whether the 22-week timeline set by the federal government is sufficient.

"The courts found, as we had said, that the marine impacts haven't been properly considered, so of course we are going to intervene in the NEB process to ensure it's a robust process," he said.

"The federal government should not have pre-determined the amount of time the NEB should take. It's important that the process is thorough."

The new NEB process was announced following a Federal Court of Appeal decision in late August that halted construction of the pipeline's expansion.

The court found the regulator failed to adequately consider the impact of tanker traffic on the marine environment.

The ruling found the federal government also failed in its constitutional duty to "engage in a considered, meaningful two-way dialogue" with First Nations affected by the project.

Natural Resources Minister Amarjeet Sohi said Ottawa will appoint retired Supreme Court Justice Frank Iacobucci to oversee the new round of consultations with 117 First Nations.

As an intervener in the NEB process, the B.C. government says it will advocate for meaningful engagement with Indigenous groups and a proper assessment of the effects of increased shipping on marine life, including southern resident killer whales.

B.C. Green Party Leader Andrew Weaver and Green MLA Adam Olsen, the party's spokesperson for Indigenous relations and reconciliation, have also applied to intervene in the NEB hearings.