Black water is water from you home that comes from things in your home that is not clean. For example, clean water comes from the water heater, from the sink when your running water, from the back of the toilet, and in the shower out of the faucet. The black water in the home comes from sources that are not clear, not clean. Black water in the home comes from the toilet overflowing, from the sewage pipes in your home, the release pipes from the washer, from the garbage disposal and similar type areas of your home.