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0.5 HP, 230 volt, 1 phase, and 60 Hertz. Controls will be provided in the plant control panel. A submerged opening will be installed in the wall between the anoxic and aeration chambers to allow mixed liquor flow transfer from the anoxic chamber to the aeration chamber. A partially submerged opening will be installed in the wall between the anoxic and aeration chambers to allow surface scum to transfer to the aeration chamber. Aeration Chamber: The aeration chamber will be of sufficient capacity to provide a minimum of 24 hours retention of the average daily flow, and/or maximum loading of 15 pounds of BODS per 1,000 cubic feet of aeration tank volume. To ensure maximum retention and eliminate short circuiting of raw sewage, the aeration chamber will be constructed with air diffusers placed longitudinally along one side of the chamber so as to, in conjunction with the flow control baffles, enhance the spiral rotation of the chamber contents. To ensure adequate circulation velocity, the proportion of the chamber width to depth, in the direction of rotation, will not exceed 1.33 to 1. The velocity of rotation will be sufficient to scour the chamber bottom and prevent sludge filleting as well as to prevent the escape to the surface of minuscule air diffusion bubbles and by so causing their entrapment to provide maximum oxygenation efficiency. Within the aeration chamber will be a mixed liquor recycle pump rated at a minimum of 100%ADF. The pump will be rated at 0.5 HP, 230 volt, 1 phase and 60 Hertz. Clarifier Chamber: The clarifier chamber will be of such size as to provide a minimum of 4 hours retention, based upon the same design flow rates governing the aeration chamber and will have proper baffling to prevent short circuiting and to provide maximum uniform retention. The total settling volume will include the volume of the upper 1/3 of the sludge hopper or hoppers. Flat bottom area of hopper will in no case be greater than one square foot. The slope of the hopper walls will not be less than 1.7 vertical to 1.0 horizontal. Settled sludge will be returned from the sludge hopper to the aeration chamber by use of an airlift pump. The clarifier effluent will pass over the edge of the baffled effluent weir into the effluent trough and then out of the chamber. The effluent weir trough will be equipped with adjustment to permit precise leveling of the serrated weir after plant installation. Sludge Recirculation System: There will be installed within the clarifier chamber a positive sludge recirculation system consisting of one (1) airlift sludge return assembly with a recirculation capacity ranging Page 5 of 11