Space ports Enviro tanks

Space ports Enviro tanks‏

Similar to the waste processing tanks of spaceships, space ports, space stations and cities have engineering sections and waste treatment and recycling facilities.

Part of the waste processing is bio digestion and that occurs in bio reactors or more commonly referred to as Enviro tanks.

Side Note: the Port Roaches of Twilight Port  found a spot on sublevel nine, behind the Space ports Enviro tanks for a "Nest" or Dry Pad"