Yes. The concern about leaving the clause open-ended was that some could put forward any kind of proposal to remediate environmental damage when perhaps it was a question of degrees and might be something that a competent authority, such as a ministry of the environment, the Canadian Nuclear Safety Commission, etc., would not require. Remediation measures would not be significant, and that's why this provision was added into the clause.
On December 4th, 2007. See this statement in context.