Florida Drinking Water Operator "B" Practice Test

If using chloramines, what is the minimum required chloramine residual needed in the distribution system?

1. 0.2 mg/l

2. 0.4 mg/l

3. 0.6 mg/l

4. 0.8 mg/l

The correct answer is: 0.6 mg/l

The correct answer is based on regulatory guidelines and best practices for maintaining water quality in the distribution system when chloramines are used as a secondary disinfectant. Chloramines, which are formed by the reaction of chlorine and ammonia, provide residual disinfection potential that helps prevent microbial regrowth in the water distribution system. A minimum chloramine residual of 0.6 mg/l is generally recommended to ensure adequate disinfection. This level is sufficient to provide ongoing protection against bacterial contamination and meets health and safety regulations set forth by entities such as the Environmental Protection Agency (EPA). This target level is particularly important for ensuring that water remains safe for consumption throughout the entire distribution system. Lower levels of chloramine could lead to insufficient disinfection, increasing the risk of microbial growth and potential health hazards. Thus, maintaining a residual of at least 0.6 mg/l in the distribution system supports both public health and regulatory compliance.