The first step to the process Wastewater flowing into the plant first passes through bar screens, to remove larger and stringy material, then grit basins, to settle solids significantly heavier than water. Both steps serve mainly to protect downstream equipment. Material collected from the screens and grit basins is sent to landfill. Large pumps lift wastewater leaving the grit basins into the primary tanks.
Continuous scrapers push collected material to one side of the tank.
Heavy material settled out is included in feed to the anaerobic digesters and floating material is sent also to landfill. After preliminary and primary treatment about half of the pollutants in the wastewater entering the plant will have been removed. Microbes hard at work To further reduce organic pollutants the biological, activated sludge process is employed. The process is accomplished in two steps. Air is blown through the aeration basins to provide oxygen for the microbes to breathe and consume the pollutants.