The day before a planned Parliament Hill protest against a proposed oil pipeline that will stretch from Alberta to Texas, the minister responsible for the file says he is confident a main stumbling block has been cleared.

One of the strongest arguments of the Keystone XL pipeline that has emerged from critics in the U.S. is the risk it would pose to ecologically sensitive areas. The most notable of these areas is the Ogallala aquifer in Nebraska, which supplies water to eight U.S. states.

In an interview with CTV's Question Period on Sunday, Canada's Natural Resources Minister Joe Oliver said the safety risks for the aquifer have been assessed.

"It's not up to me to say there is no risk," Oliver said. "It's up to U.S. scientists to make a determination that it is safe, and they did.

"They said this pipeline will be safer than existing pipelines," Oliver said, adding there are already hundreds of kilometres of pipeline going through the area.

"The issues are serious, but they have been dealt with," he said.

Nebraska Gov. Dave Heineman, a Republican, is among the politicians who have gone public with opposition to the pipeline, saying an oil spill in the aquifer is too big a risk to take.

The governor has asked U.S. President Barack Obama and Secretary of State Hillary Clinton, who are responsible for approving or denying the permit for the pipeline, to scuttle the project.

The U.S. State Department will hold hearings in Nebraska before deciding whether to approve the project.

Oliver told CTV on Sunday that he not only expects a U.S. decision on the pipeline will come soon, but he is also optimistic of the outcome.

He said Canadians would benefit from the project through the creation of 140,000 jobs and $600 billion in economic activity over 25 years.

But the minister also conceded that Canada, which now exports 97 per cent of its oil to the U.S., must diversify its markets. He said action must be taken to build a pipeline from Alberta to the coast of British Columbia to export oil to Asia, especially China.

Meanwhile, organizers of the protest planned for Monday on Parliament Hilll said many of the demonstrators are prepared to be arrested to highlight the cause.

The protest will duplicate a similar sit-in outside the White House in Washington, D.C. last month, where scores of people were arrested, including actresses Margot Kidder and Daryl Hannah. The images of celebrities being hauled away hit TV and newspapers worldwide, raising the profile of the issue, just as activists hoped.

The protesters both in Canada and the U.S. have two main arguments. They believe the proposed Keystone XL pipeline extension from Alberta to Texas is an environmental disaster waiting to happen. The pipeline will serve to ramp up production in the Alberta oil sands, they say, and increase greenhouse-gas emissions as a result.

At issue is TransCanada Corp.'s Keystone XL pipeline extension intended to eventually carry 900,000 barrels per day of crude from Alberta to refineries in Texas where it would be processed into oil.

The Council of Canadians, the Indigenous Environmental Network and the Polaris Institute will join the protest on Monday. Actors Dave Thomas of SCTV fame and Graham Greene (Dances with Wolves) also plan to demonstrate.

In an email, organizers said many of those who have signed up to protest "will risk arrest in what is expected to be the largest civil disobedience action in the history of Canada's climate movement."

Where environmental activists weigh in against bolstering fossil fuel development, Canadian unions and even former Alberta premier Peter Lougheed have raised questions about exporting jobs to the U.S.

Lougheed said in a recent interview said the oil should be processed in Alberta to keep jobs in the province.

With files from CTV News and The Canadian Press