Portable holding tank

A portable tank for waste liquids comprising, in combination, a receptacle molded of a synthetic plastic material having upper and lower portions, a front side, a rear side and lateral sides, an inlet port defined in said upper portion, an outlet port defined in said receptacle in one of said sides adjacent said lower portion, a valve defined in said outlet port movable between open and closed positions controlling liquid flow through said outlet port, said receptacle lower portion comprising surfaces inclined downwardly toward said outlet port, said valve including a gate, guide means defined on said valve adjacent said outlet port, a gate handle defined on said gate for moving said gate between open and closed positions, a wheel mounted on said receptacle adjacent each lateral side and located adjacent said rear side, a steerable wheel mounted on said receptacle adjacent said front side and a tank handle pivotally mounted at said receptacle front side.