Wastewater Treatment Plant Process
When you flush your toilet, wash your hand, use your dishwasher or washing machine it goes down the drain into a pipe. The pipe from your home leads to larger pipes in the street. Those larger pipes lead to the Wastewater Treatment Plant.
Influent is the wastewater coming into the plant. A device called a flow meter measures all the flow coming into the plant.
Headworks is the first step in the treatment process. In the headworks there are barscreens that take the debri out of the wastewater. Debri includes rags, plastic, diapers, food, feces, tiolet paper, sticks, rocks, and sometimes even money. It important to capture the debri because otherwise it can cause damage to the plant equipment.
Primary Clarifier is a physical cleaning process. It is an important part of the treatment process because it removes solids from the wastewater. This is completed over the course of several hours, the heavy solids sink to the bottom of the tank. It becomes a thick slurry material known as primary sludge. The material that floats to the top, such as Oil & Grease is skimmed off the top by skimming arms. Both materials are pumped to the solids treatment process.
Trickling Filter is a (secondary process) biological process to help clean the wastewater. It has arms that spray wastewater over the rocks called media. The wastewater trickles through the rocks. Over time the population of microorganisms creates a layer or film of slime over the rocks.The microorganisms eat the sewage out of the wastewater to help clean it. The aerobic conditions (meaning the movement of the air) keep the microorganisms eating. When too many microorganisms build up they fall (or slough off).
Intermediate Clarifier there are two intermediate clarifiers at the wastewater treatment plant. Both of the units do the same thing and work like the Primary Clarifier by removing solids from the wastewater.
Aerotors is an aerobic process. The wastewater is constantly having air circulated through its several hour stay. The microorganisms are again helping clean the wastewater. Wastewater from this location is sent to one of two Final clarifiers.
Digesters at the wastewater treatment plant are an anaerobic unit. There are two types of digesters, Primary & Secondary and do the same thing. They create an anaerobic environment is created in these tanks. Microorganisms that do not like air live here and eat the sludge. Sludge is kept between these two tanks for about 4 weeks. After that time period, the sludge is wasted, meaning it is pumped over to our drying beds. Methane gas is released and burned off.
Final Clarifiers. There are two final clarifiers at the wastewater treatment plant and they do the same thing as the Primary and Intermediate clarifiers, they remove sludge from the wastewater. The scum from the top of the clarifiers is pumped to a scum box. The sludge on the box is pumped over to the Aerotors and DAF thickener. The wastewater pumped over to the Sand Filters point for further treatment.
DAF Thickener thickens the sludge and put air into it. The sludge goes into the Primary digester to be processes. The wastewater goes back to the primary clarifier and starts the process all over again.
Sand Filters, filter out anything that might have bypassed through the system. It works by the wastewater passing through the sand. Shallow bed and traveling bridge. The microorganisms eat the solids.
Chlorine Contact Basin is where chlorine is injected into the wastewater. The wastewater has to set inside the channels (which look like a maze) of the chlorine contact basin for several hours before it is discharged in the Beer Creek.
Drying Beds are where the sludge from the Digesters and debri from the headworks is dried. We do not sell the sludge, but after it is dried and passes special test, it is hauled up to the landfill where is cannot come into contact with the public for one year. Any wastewater from the sludge is sent back to the headworks. There are nine drying beds with asphalt with under ground drains.
Dewatering Unit has a belt that squeezes the excess water out of the sludge. The sludge is then dropped into the back of the truck and will be hauled to the landfill.
If you would like to learn more about the Wastewater Treatment Plant you can request a tour at 801-465-5277.
To the right is a video from Wastewater Treatment P.S.A. (Metropolitan Water Reclamation District of Greater Chicago) explaining the wastewater treatment process.