[yaroslavvb]

Stricter (but not looser) standards can be imposed on state level. Canada has no binding national drinking water law, they leave it to territories/provinces to decide how to implement guidelines.

[sgnelson]

Watersheds don't follow political boundaries.

[8note]

sometimes they do.

the Alberta/British Columbia border is defined by which direction water drains off the mountains

[BobaFloutist]

That sounds like the political boundary follows the watershed.

It also doesn't actually refute the actual point they were making.