You might want to read further on this topic by visiting the engineering company'a page on this facility's website (Savannah's info on this plant is slender):
Savannah has four water reclamation plants; the one above processes 40 million gallons per day.
You might want to read a brief description of Savanna's "sewer modeling" off of this link:
The facility above is open for tours for schools and some corporations. I am bummed that I am in neither category!