I have a few horses, goats and chickens. I was interested in adding ducks for additional pest control. I use a 3/4 acre pond about 20 feet deep for my drinking water and was instructed to keep the ducks and geese out of the water. I was also told that Moscovy ducks are not a threat to my water supply. Can anyone help me? Is one breed of ducks safer for my water supply than another?