Ventilation for sewage lift station

there is a design drawing, which shows air blower sucking from lifting station and throwing up in air. And there is no vent pipe shown on drawings.Lift station has cover.

Can any one suggest, what will be best way to ventilate the lift station?

As i know that stagnant sewage water produce Methae and Hydrogen Sulphide , which are very dangerous.

How to size the blower and and how its running time to fixed? and how can i put manual (GHOOSE neck) vent pipe.

thanks in advance.