A vacuum tank assembly is provided for use on an RV or a boat and includes a two-piece vacuum tank. The two-piece vacuum tank includes a body and a removable top with a gasket located between the body and removable top. A dip tube is integrated into the removable top, thus, forming an opening in the removable top and thereby reducing maintenance problems associated with mechanically attached dip tube assemblies. A vacuum pump is provided to pump the waste out of the vacuum tank into a holding tank.