Located along the Kennebec River Rail Trail, the wastewater treatment facility is an activated sludge, secondary treatment plant.
Wastewater treatment is a complex process that treats large quantities of water. The wastewater treatment facility treats an average of 4 million gallons per day (MGD) of wastewater, with flows reaching 40 MGD during rainstorms. This requires large and expensive equipment, especially pumps.
Wastewater is screened when it first enters the wastewater facility. Screens made of steel with automatic raking systems remove most of the large "stuff". Next, a grit separation system is used to help remove sandy, heavy materials. The water then flows to the primary clarifiers which "clarify" the water by allowing solids to settle out, leaving cleaner water to flow to the aeration tanks. Our site is "footprint limited" which means it's very small compared to other facilities. This can only be done by making the aeration tanks really small which requires pure oxygen. The oxygen flows into the aeration tanks where it provides oxygen for bacteria that we want to grow so they can get fat and settle out in the secondary clarifiers. These round tanks provide a second means of clarification which removes even more solids from the wastewater. In the winter, the water from the secondary clarifiers flows into the Kennebec River with no further treatment. In the summer, the water from the secondary clarifiers is treated with a disinfectant to kill remaining organisms in the water. Then the disinfection chemical is removed before the water is discharged to the Kennebec. Simple: screen, settle, add air, settle again, disinfect, discharge.
One of our biggest problems is pumps get clogged with baby wipes, which should never be flushed down the toilet. Check out the "Save Your Pipes, Don't Flush Baby Wipes" flyer here.
The image below is an overview of the wastewater treatment process: Click to enlarge