My kids learned to swim in our pond. We know what's in our watershed. Livestock is the greatest risk for contaminated water. Drowing is a serious risk, and with merky water, you need to keep an eye on the kids. Our are now 14 and 16, so less of a worry, but we always supervise the swimming. BG will nip, but our son and daughter are tough and such little things don't bother them. Although, we teased my son that he might have to wear a girls bathing suit after he got both of his nipples bit.