It's just a tailings containment area. To go a step further, early testings—and this has to continue—are to try to identify whether there's any hazardous element in the tailings. So far we think it's very manageable. That's what will continued to be investigated during the environmental assessment process, because there are ways to manage these things.
Evidence of meeting #26 for Natural Resources in the 41st Parliament, 1st session. (The original version is on Parliament’s site, as are the minutes.) The winning word was project.
A recording is available from Parliament.