Bill C-39 is largely about process. The primary change is to do assessments and permitting in a concurrent way as opposed to a consecutive way.
Most of the changes you see through Bill C-39 are changes to process to make things run quicker. There aren't any changes to environmental standards. For example, the environmental criteria that are set up in the Impact Assessment Act remain and the environmental criteria in the CER Act remain.
The environmental standards remain the same in Bill C-39, as they were pre-existing. It's a bill about process.