Thank you for your question.
Yes, Environment Canada is involved in monitoring the impacts of sewage effluents. I guess some of the main concerns with sewage effluents are about antibiotics, birth controls, and these kinds of endocrine disrupters, compounds that will disrupt the endocrine system or the hormone system.
They do monitoring. Usually sewage effluent is more of a localized problem. Within 50 kilometres of a source, you'll detect a signal, but soon after that.... They say that the solution to pollution is dilution. By the time it reaches the Peace–Athabasca Delta, those levels are near background levels, so it's not a huge concern.