The first rainwater treatment plant is made with monolithic polyethylene tanks, designed to be buried and constructed using rotational molding with a constant thickness. The system consists of four distinct elements:
- Stormwater Overflow Chamber: Suitable for the separation of first rainwater.
- Storage Tank: Sized to retain the first 5 mm of rain that falls on an impermeable surface.
- Calm Chamber
- Coalescence Oil Separator: To remove oils and fats present in the accumulated water.
A submersible pump with a recessed impeller is installed inside the storage tank, which lifts and transfers the accumulated effluent to the next phase of oil separation. The effluent exiting the system can be discharged into surface water or sent for further treatment stages. The structures are equipped with vents, inlet and outlet pipes, and inspection and maintenance caps.
