Package Sewage Treatment Plant of 50,kld capacity consisting of Fiber glass reinforced Plastic (FRP) tank made by filament winding process from suitable polyester resin and glass fiber of the tank with suitable polyester resin and fiber glass to make tank suitable for underground application process variation. The tank to have three zones - the first zone to work as anaerobic septic zone created with the suitable partition of FRP; second zone to be created by the partition of FRP with advanced fab media with a surface area to volume ratio of minimum of 400 Sq. Mtr / Cubic meter suitably encased free movement of the media within fixed space created by the net; the third zone to work as sedimentation zone in the remainder area of the tank. Aerobic zone has Twin Lobe Air Blowers installed for providing air flow coarse aeration in the zone for speedy reduction of BOD. Sedimentation zone have a submersible pump of the for pumping the activated sludge back to the anaerobic zone by way of PVC pipes The whole plant to be controlled by automatic control panel made from sheet molded compound