"One thing we're noticing is that there's not optimal collaboration between the Quebec government, that's now leading a formal investigation, and the federal government," said Patrick Nadeau, executive director of the Ottawa Riverkeeper.

"An example of that is that the Quebec government is refusing to say whether or not it took sediment samples in the Lièvre River, but we know that the federal government has. So are they sharing those results? Are they collaborating on these investigations? It's hard to say."