It depends on what you're talking about as guidelines. In Canada we have 12 different jurisdictions—I guess 13 now—that implement drinking-water controls, and places like Alberta have adopted the health-based Canadian guidelines as regulatory requirements. As I understand the requirements in Ontario, the Ontario drinking water objectives are legally required. I can't argue that drinking water is safer in Alberta than it is in Saskatchewan. But ultimately, it comes back to—and I hate to sound like a stuck record—the focus on operational competence. If you can legislate that, then go for it, because that's what we need. We need to have the support of the systems, the resources, to make sure the job gets done right. Having an open-ended list of chemicals with the most stringent standards in the world will not provide you with safe water.
On March 28th, 2018. See this statement in context.