This invention relates to an ecologically and environmentally friendly mud-gas containment system. Specifically, this invention relates to a mobile device that is capable of receiving waste gas and, in emergency situations, a volume of a mud-gas mixture from a drilling operation. The waste gas is communicated to a removable flare stack through a vent line. The mud-gas is received at a containment vessel. The impact of the mud-gas within the containment vessel separates the mud-gas into mud and waste gas. The mud is collected for recycling and/or environmentally sensitive disposal. The waste gas from the vessel is communicated to the flare stack. Separate removal ports and conduits are used to remove any residual mud or mud-gas from the vent line and/or containment vessel. Excess mud or mud-gas is communicated to an overflow catch tank for removal. The entire assembly is mounted on a mobile skid sized for highway transportation.