not shown waste tank recess 30 is created by forming surround supports 32 34 and 36 specifically left hand support 32 is situated on the left side of recess 30 rear support 34 is situated on the back side of recess 30 and right hand support 36 is situated on the right hand side of recess 30 further floor supporting structure 24 surrounds recess 30 on a front side thus providing support on all four sides of recess 30 in the preferred embodiment the base structure is a single roto modeled part which is a single integral component further restroom base 20 is configured to cooperate with the other components creating the enclosure as generally illustrated in fig1 referring now to fig4 a bottom view of restroom base 20 is illustrated more significantly fig4 provides additional detail regarding supporting structure 24 which provides an improved floor structure for the portable restroom of the present invention as mentioned above supporting structure 24 bridges the space between first runner 26 and second runner 28 thus providing a base framework upon which the remaining portion of the portable restroom can be formed the supporting structure itself includes a number of main ribs 40 which are each molded into the bottom surface of restroom base 20 these main ribs 40 extend across the entire structure and are configured somewhat consistently with conventional supporting ribs between each of the supporting ribs a support web 42 exists made up of a plurality of arched portions 44 which each extend upwardly to eventually contact an upper layer of floor structure 20 referring now fig7 a more detailed view of this supporting.