A waste fluid containment and draining system for a motor vehicle, the system comprising: a black waste water holding structure for holding black waste water; a grey waste water holding structure for holding grey waste water; a first valve (22, 120) associated with the black waste water holding structure enabling emptying of the black waste water when the first valve (22, 120) is opened; a second valve (24, 122) associated with the grey waste water holding structure enabling emptying of the grey waste water when the second valve (24, 122) is opened; a macerator pump having an input in flow communication with both of the first and second valves (22; 120) and (24, 122); and a control subsystem 46 in communication with the first and second valves 22 and 24 and the macerator pump 118 for controlling the first and second valves 22 and 24, together with the macerator pump 118, to enable operation of the macerator pump 118 and selective pumping out of the holding structures through a discharge conduit 36 in flow communication with an output of the macerator pump 118; characterized in that the system includes a central tank in communication with both of the first and second valves (22,120) and (24,122); and wherein the macerator pump is disposed in the central tank and in communication with the first and second valves (22,120) and (24,122) or wherein the black waste water holding structure and the grey waste water holding structure are formed in a single holding tank by at least one partition included within the single holding tank, the single holding tank includes a central compartment within which the macerator pump is located. a black waste water holding structure for holding black waste water; a grey waste water holding structure for holding grey waste water; a first valve (22, 120) associated with the black waste water holding structure enabling emptying of the black waste water when the first valve (22, 120) is opened; a second valve (24, 122) associated with the grey waste water holding structure enabling emptying of the grey waste water when the second valve (24, 122) is opened; a macerator pump having an input in flow communication with both of the first and second valves (22; 120) and (24, 122); and a control subsystem 46 in communication with the first and second valves 22 and 24 and the macerator pump 118 for controlling the first and second valves 22 and 24, together with the macerator pump 118, to enable operation of the macerator pump 118 and selective pumping out of the holding structures through a discharge conduit 36 in flow communication with an output of the macerator pump 118; characterized in that the system includes a central tank in communication with both of the first and second valves (22,120) and (24,122); and wherein the macerator pump is disposed in the central tank and in communication with the first and second valves (22,120) and (24,122) or wherein the black waste water holding structure and the grey waste water holding structure are formed in a single holding tank by at least one partition included within the single holding tank, the single holding tank includes a central compartment within which the macerator pump is located.