Where effluent discharges are required to be chlorinated, a chlorine contact chamber should be used to disinfect the wastewater before distribution. Calcium hypochlorite, labeled for wastewater disinfection, shall be added in sufficient concentrations to maintain a minimum residual of 0.5 ppm total chlorine in the effluent. To achieve the required contact time for chlorine, a baffled chlorine contact chamber shall be used with recommended gallons per day (GPD) capacities.

Design

The chlorine contact chamber is located after the primary treatment and before the effluent is dispersed through a distribution system like spray irrigation. Standard 4-inch PVC pipes will be used for the connections. In the chamber, a 4-inch minimum PVC tee with a restrictive insert will be used to control the effluent flow. The insert is cemented onto the PVC tee with the restriction pointing down. This allows for the effluent to have more contact time with the chlorine to ensure sufficient treatment. Owners should monitor chlorine residual with a color indicator and record every six months for single homes, monthly for clusters or as required by law for other units. There may be opportunities to adjust residuals by varying the number of tubes to be stocked. Restock chlorine feed tubes as necessary to ensure sufficient concentrations are being maintained. This is roughly an average of every six months for a single home and every month for clusters. For preventative maintenance, it’s best to clean the unit internally every six to 12 months by flushing or pumping out and scraping residual chlorine from the tubing.

Stack Feed Chlorinator