Apparently not a single person on here knows how well water systems work, otherwise a dog pooping in a river would be the least of your worries. Allow me to explain. If your house or apartment doesn't have a city water hookup then you have a water well and pump on your property. If you have well water and you do not have a sewer hookup, I have some delicious news for you. Go over to your sink and pour yourself a nice refreshing glass of water and have a drink before we continue. Ok, feel better? That water you just drank used to be the same water that was in your toilet the last time you took a massive dump. Delicious right?

All of the water that goes down the drain in your house goes into a big pipe and out the basement wall usually, and then out into a septic tank, and then that holds the solid wastes, and then the liquid wastes get filtered out through a leach bed which is just gravel and probably sand and dirt. The well and septic tank usually have to be so far apart on a property to keep it safe.