To protect the public from disease-causing organisms commonly found in wastewater, the plant is required to disinfect the finished wastewater before discharging it to the Tioghnioga River. Disinfection is required from May 15 to October 15.
Disinfection is achieved at this facility through chlorination using chlorine gas followed by dechlorination using sulfur dioxide gas. The plant employs an automated chlor/dechlor system. Chlorine feed-rate is adjusted by microprocessor-based process loop controllers actuating gas feed units. A process chlorine analyzer continually monitors the actual chlorine residual in the Chlorine Contact Tank. Enough chlorine is added to achieve a 1.2 milligram per liter dosage. The purpose of the Chlorine Contact Tanks is to allow sufficient time for the chlorine to disinfect the water.
The chlorinated wastewater enters the tank at the far left as shown in the photo. The baffles ensure maximum detention time by preventing short-circuiting. At the last baffle (at the left of the photo) sulfur dioxide is added to neutralize the chlorine prior to discharge to the receiving stream. The final section of the tank is aerated to increase the water’s oxygen content before discharge to Tioghnioga River.