Your sewer or septic tank is plugged. If you are in a modile home park or connected according to the old conventions, then you may have a P trap underground at the trailer connection. If so dig it up and remove it.: I have 1996 Belmont Mobile with 2 bathrooms. Does all septic pipes have to be connected in order for drains to work? I have the back bathroom hooked up and the front bathroom is not being used. I have drain water backed up in the back bathroom and the toilet drain is plugged. Water has leaked into the batting under the trailer. I need help ASAP. please call me @ 334-988-1663