OTTAWA -- Major new energy projects will have to be assessed and either approved or denied within two years under a massive new national assessment bill being introduced in the House of Commons.

Environment Minister Catherine McKenna, who introduced the 341-page Impact Assessment Act Thursday morning, said it will provide clarity and certainty about how the process works, what companies need to do, and why and how decisions are made.

"Canada just upped its game today," McKenna said.

She said the new system will help improve certainty to attract investments and prevent the polarization of sides and legal battles such as those currently affecting the Trans Mountain pipeline project. That project, to triple the capacity of an existing line between Alberta and British Columbia, was approved under interim principles put in place by the Liberals in early 2016, but is still mired in controversy.

McKenna said the new system sets legislated time lines for making a decision, lifts the restrictions on who can participate in an assessment process to allow more people to weigh in and requires the reasons behind a decision to be made public, including access to the science used in each case. She believes all those things will help return confidence to a system she says is broken.

Under the new act, the Canadian Environmental Assessment Agency will be renamed the Impact Assessment Agency of Canada and reviews will look at far more than just the impact on environment. Health, social, and economic effects will also be considered, as will the effect on Indigenous rights. A gender-based analysis will also take place on every project.

Decisions will be made based on the pros and cons of a project, including its contribution to sustainability, the extent of any adverse effects and how they will be mitigated, the impacts on Indigenous lands and rights and how it will affect Canada's ability to meet its environmental and climate change commitments.

The assessment agency is to become a one-stop shop for all assessments, including trying to co-ordinate with provincial governments so any project proponent only has to go through one review before a decision. The biggest or most involved projects will be assessed by a review panel appointed by the minister, while smaller projects will be looked at by the assessment agency.

Review panels will have 600 days, rather than 720, to complete their work and cabinet will make the decision whether a project goes ahead, within 90 days. The agency assessments will take a maximum of 300 days -- down from 365 -- and decisions made by the minister of environment in no more than 30 days.

Before a proponent even submits an application for review, they will be required to undergo an early planning phase, of a maximum of six months, to try and work with various stakeholders, including Indigenous communities, ahead of time to see what issues and concerns might arise.

McKenna said "smart proponents already do this."

"If you don't do the work on the front end you're just not going to get to a conclusion quickly and you may end up in court or having protests," she said.

The National Energy Board is being remade into the Canadian Energy Regulator, with some changes including requiring at least one board member be Indigenous and that expert panels used by the regulator include expertise in Indigenous knowledge, municipal issues, engineering and environmental issues. The CER, as it will be known, will remain based in Calgary, an official rejection of a recommendation last year to move at least some of the board's functions to Ottawa.

The federal government will spend $1 billion over the next five years to implement the new process, including hiring more scientists to review impact statements from project proponents.

Both the Canadian Energy Pipeline Association and the Canadian Association of Petroleum Producers said they were pleased with the legislated timelines and the "one project, one assessment" philosophy behind the new act.

Tim McMillan, president of the petroleum producers, said the early-engagement requirement could be great, but he wants more information.

"There may be some work that needs to be done before the clock is started," he said. "If that is more cumbersome or onerous than what we had before, it may actually be a net negative. If this is done really well, maybe that does mean there's a benefit."

The CEPA is concerned issues such as climate change will be taken into consideration, saying it is subjective and could make decisions political.

University of Ottawa law professor Stewart Elgie, who specializes in environmental and natural resource law, says the bill will make Canada the only country in the world with national assessment legislation that requires the government to consider sustainability and climate change commitments when deciding whether to approve a project or not.

"That is real environmental teeth," he said.

However other environmental groups say it's not clear how Canada will determine if a project meets those climate change commitments or not.

Megan Leslie, a former NDP MP and now president of World Wildlife Fund Canada, said climate is only a consideration, not a requirement. Leslie said the increased transparency requirements are a net gain however.