Sodium hypochlorite dosage for household and emergency water treatment.

NaOCl dosage recommendations for both household water treatment and disaster response water treatment vary significantly. In this study, 106 water samples from a variety of improved and unimproved sources in 16 countries were tested to ascertain whether a standardized NaOCl dosage regime could be developed. Results indicated that for household water treatment with NaOCl alone, a dose of 1.875 mg/L NaOCl proved effective in 86.6% of samples with turbidity < 10 ntu and a dose of 3.75 mg/L NaOCl was effective in 91.7% of unimproved sources with turbidity of 10–100 ntu. On the basis of test results, it is also recommended that POU chlorination programs adopt a proposed criteria for a free chlorine residual of < 2.0 mg/L 1 hour after NaOCl addition and > 0.2 mg/L after 24 hours of storage. Journal of the American waterworks association. 2008;100(8).