The Ashland Water Pollution Control Facility is a trickling filter - solids contact treatment process. The raw wastewater enters the plant by gravity at the influent pump station. Prior to pumping, the wastewater flows through a bar screen to remove large debris.
Wastewater is pumped to the intermediate screening building where organic material is removed.
The wastewater is then aerated and grit is removed. All solids, to this point, are landfilled. The water then flows to primary settling. Solids removed at this step are pumped to holding tanks to await further treatment. Water is now pumped to trickling filter towers.