Madam Chair, of the roughly between 1,500 and 2,000 spills that occur across Canada every year, Environment Canada personnel very rarely attend the scene. They do, and there have been instances in recent months, where they have been requested by a lead agency, be it a province or a federal ministry, such as the Department of Transport, for example, with two recent rail accidents. However, for the most part, they support telephonically with advice and scientific data to assist whatever lead agency is in charge with the cleanup.
In the House of Commons on May 15th, 2012. See this statement in context.