OTTAWA - Legislation overhauling Canada's assessment of major energy projects is back in the hands of Environment Minister Catherine McKenna, albeit looking a lot different than when she introduced it.

The Senate passed the Impact Assessment Act late Thursday with more than 180 amendments.

The changes take power away from the environment minister to intervene in or slow the assessment process, reduces the ability for legal challenges of project approvals and adds more emphasis on economic considerations when deciding whether to go ahead with a particular project.

The government now has to decide which of those amendments it will accept as it tries to fulfil a 2015 campaign promise to fix Conservative-era assessment legislation the Liberals say created a broken system that blocked public participation and negated environmental concerns.

Environmental groups felt Bill C-69 originally delivered some balance between the environment and the economy as the country makes its way through a transition to a greener, cleaner energy sector.

Oil industry executives decried it as a bill that would prevent any new major energy projects from ever being built while Alberta Premier Jason Kenney says the bill is a nightmare for national unity.