Social & Preventive Medicine The minimum recommended level of residual chlorine in the drinking water is for one hour A 0.5 mg/L B 0.25 mg/L C 1.0 mg/L D 2.0 mg/L 💡 Explanation The minimum recommended level of residual chlorine in the drinking water is for one hour ✓ Correct Answer: A. 0.5 mg/L