Hypochlorination of Wastewater Effluents in New York City

In 1964-65 New York City converted its wastewater treatment plants from the use of liquid chlorine supplied in ton containers to the use of a sodium hypochlorite solution. For their conditions, this conversion has proven safe, simple, feasible, and financially warranted. Studies continue on determining the best solution tank material and linings to be used. All plants have been converted and effluent quality is improved. In general it appears possible to operate at residuals lower than were maintained previously at a savings of at least eight percent in hypochlorite usage. Safety considerations as affected by City codes prompted the conversion.