The committee on water supplies of the Sanitary Engineering Section of the American Public Health

Association has recently submitted its report.1 In answer to requests for information regarding the extent and efficacy of the hypochlorite treatment no replies were received. About 75 percent of the waters treated were from rivers, 20 percent from lakes, and the rest from wells. The total daily output of treated water was nearly 2,000 million gallons. The average cost of treatment is 25 cents per million gallons. In very bad waters, such as the Bubbly Creek in Chicago, 60 pounds of hypochlorite per million gallons of water are used. The minimum quantity reported was four pounds per million gallons. Only about 30 percent of the plants reported tested the treated water for free chlorin. Great variations are found in the strength of commercial hypochlorites. The maximum percent of available chlorin was 44 and the minimum 15, and the average, 33 percent. The percent of bacteria removed by the chlorination process is found to be about 98.