B.C. Environment Minister Mary Polak is defending her government's decision to approve Kinder Morgan's Trans Mountain pipeline expansion project.

On Wednesday, the provincial government issued an environmental assessment approval for the project which will triple the capacity of an existing pipeline between Edmonton to a terminal in Burnaby, B.C.

The provincial government was required to conduct its own environmental assessment as per a Jan.13, 2016 B.C. Supreme Court ruling.

Earlier last year, the B.C. provincial government said the project had fallen short of its five provincial requirements particularly with regards to marine spill preparedness.

On CBC's The Early Edition, Polak said things have changed since then.

She pointed out that the federal government approved the project and made a serious investment in marine safety.

"Not only has there been an incredible investment on the coast by our federal government, the lion's share of that $1.5 billion investment is going to go to B.C.," she said.

As for whether more should be done to protect B.C.'s marine environment, Polak said much of it was out of the province's jurisdiction.

"The court decision was very clear in saying — in fact, explicitly — that B.C. had no jurisdiction to place conditions on a certificate for this project that would frustrate those things that are within the federal control," she said. "The effects on the marine environment is squarely within the jurisdiction of the federal government."

She said the provincial government has made 37 conditions within its own jurisdiction to support the 157 conditions the federal government has imposed.

The provincial approval hasn't stopped opponents.

Mayor Lisa Helps of Victoria and Mayor Derek Corrigan of Burnaby both expressed a commitment to continue their opposition.

"The conditions are better than nothing, [but] I am still not in favour of the pipeline because the risks are too great based on the benefits we would accrue," said Helps.

Corrigan said people can use the May 9 provincial election to decide whether, "they want a weak provincial government."

The project is still subject to two court challenges before the Federal Court of Appeal and the B.C. Court of Appeal, he added.

Charlene Aleck, a councillor with the Tsleil-Waututh First Nation, whose traditional territory lies across from the pipeline's terminus in Burrard Inlet, also expressed disappointment.

"If this project goes through, a spill in our inlet would drastically change so many things. Not only culturally, but our way of life … The ecosystem, the animals, the fish, the crabs."

Aleck has also vowed to fight the project through the courts.