Preliminary Treatment

Bar ScreensBar Screens
The sewage is first pumped using three enclosed screw raw sewage pumps which provide a means of lifting the incoming sewage from the sewer system. The sewage then passes through the bar screens for rag removal.

In this section two automatic bar screen cleaners remove large solids (rags, plastics, etc.) from the raw sewage. The collected material is placed in dumpsters to be later taken to the landfill. The action of the bar screen equipment is paced according to the amount of incoming solids and the flow rate.

Grit TanksGrit Washing SystemGrit Tanks
Next, the sewage moves to the grit tanks. These tanks reduce the velocity of the sewage so that heavy particles may fall to the bottom.

The solids are pumped to an grit washing system which separates the water from the grit while the water moves onward. The grit (mostly inorganic solids) goes to a dumpster which is taken to a landfill. There are two complete grit washing systems which are rotated in operation for equal hours.