The wastewater treatment process begins when wastewater from the collection system enters the Central Treatment Plant at Headworks. Here four Aerated Grit Chambers are used for inorganic compounds removal, such as grit and course debris. This leaves the lighter organic particles which can pass through the tanks to the Primary Sedimentation Tanks. The water is held in the Primary Settling Tanks where the flow of water slows down and gravity removes more than 70 percent of the particles in the water. Lighter solids that float, such as grease and small plastics, are skimmed off the top of the tank.

Next, the water enters the Aeration Tanks. Here, oxygen is added to create an environment where aerobic microorganisms can live in greater concentrations than in nature, effectively speeding up the degradation process. The wastewater interacts with the microorganisms in the activated sludge and the microorganisms feed on the organic matter, forming flocs, which are heavier and easier to settle in the next step.

After the Aeration Tanks, the water moves to the Final Settling Tanks where gravity settles the heavier solids to the bottom of the tanks. The water moves into the Final Effluent Channel, where a chlorine solution is added to disinfect the effluent prior to discharge into either the Raritan River or Raritan Bay. The water is thoroughly tested in accordance with the facility’s Surface Water New Jersey Pollutant Discharge Elimination System (NJPDES) permit before being reintroduced into the environment. Approximately 10 percent of the treated water is used within the plant to cool the on-site Power Generating Facility.