Every RV with a black tank will have a connection point for a sewer hose. Put on latex gloves and attach one end of your sewer hose to the RV and the other end to the ground sewer connection. Make sure the sewer hose is securely attached to both the RV and the ground sewer connection in order to avoid leaks or spills. Open the black tank valve so the waste can empty into the sewer. It is good practice to empty the gray water tank immediately after to help completely flush out any waste. Make sure to invest in a quality sewer hose long enough to reach sewer connections often located at the rear of campsites. While it is perfectly acceptable to keep the sewer hose attached to the RV and sewer connection at a full hookup campsite, remember to always keep the black tank valve closed until you empty it.