I have looked into the commerical Uvs. for this concept for the bacteria concerns. I too looked into swim ponds as you did as its a natural transiton or addition to a business. Everywhere but the U.S. has them for our standards in water quailty for consumption and bathing is 2 even 3 times that of Europe or Asia yet they are fine. Its puzzling to think that a swimmimg pools vs ponds is that big of a debate when it comes to swimmimg or just playing in the water when it comes to the goverment. I remember growing up swimming in lakes rivers streams etc. The fact of the matter is bacteria is always present in wells ponds streams and lakes. The only time its not is when you add clorine. Nature keeps it in check. The plants, coloinzation of healthy bacteria, high oxygen levels all keep it balenced.
Most locals here dont have regs for ponds in fact the state doesnt even have a liabilty standards for homeowners they have been debating it for yours. I talked to some gov officials and they just scratched theirs heads because the concept is so forigein to them. Realistically a swim pond is just a supersized pond that is deep for swimming in. I dont know just waiting on some other info and call backs before i proceed lol..