Abstract: A self-contained wastewater treatment system is provided, comprising a vessel having a bottom, side walls and a lid defining a hollow interior for containing wastewater, the vessel being adapted for installation underground; an influent line; an effluent line; and a baffle disposed within the interior, generally between the influent line and the effluent line and extending transversely toward opposing side walls of the vessel. The baffle includes a bottom edge separated by a predetermined distance from the bottom of the vessel to define a flow opening. The position of the baffle defines an upstream aeration chamber and a downstream clarifier chamber within the vessel. The side walls include a downstream end wall, the downstream end wall having a lower inclined wall which intersects the bottom of the vessel adjacent the flow opening.

Abstract: A self-contained wastewater treatment system is provided, comprising a vessel having a bottom, side walls and a lid defining a hollow interior for containing wastewater, the vessel being adapted for installation underground; an influent line; an effluent line; and a baffle disposed within the interior, generally between the influent line and the effluent line and extending transversely toward opposing side walls of the vessel. The baffle includes a bottom edge separated by a predetermined distance from the bottom of the vessel to define a flow opening. The position of the baffle defines an upstream aeration chamber and a downstream clarifier chamber within the vessel. The side walls include a downstream end wall, the downstream end wall having a lower inclined wall which intersects the bottom of the vessel adjacent the flow opening.