Yes it was manure run off that caused Walkerton. Manure management is a self policed, un-regulated statement. I live in factory farm turf? 1000's of acres managed by number'd company's? Mostly cash crop with desveristied interest in pork or birds? I get that before a pig/chicken shit factory can be built, they have to show on paper their waste management plan, acre's equal barn size, simple math.
Once twsp approved, good to go. I also get tanks/barns have to be emptied? Depending on the crop, starting at pea harvest to hard corn last week, rain or shine, if the field is harvested, empty the tanks, dump it?
Tractors hauling tandem honey wagons run here all day, and night.
Yey, London dumping after that rain, un-exshuseable, but what is pushed down field tiles to drains, to creeks and rivers, every day?