Wastewater flows into wells at the wastewater treatment plant. Raw wastewater pumps carry the effluent to primary treatment facilities consisting of a flash mixer (which mixes chemicals in to the water), flocculators (which allows ferric chloroide to adhere to particles) and primary settling tanks. Most settable solids (those that settle out) and 40 to 60% of the suspended solids (those that float on the surface or are suspended in the wastewater) are separated and removed from the effluent.

These are the settling tanks, where all of the solids settle to the bottom of the tank. This will make it easier to separate them.		Mixed liquor tanks start the process.
This is the grease removal tank. The skimmers move across bottom to separate the solids and the liquids.		Here, the solids are removed from the bottom of the tanks. They will be sent to the sludge thickener.