How often must each filter's turbidimeter be able to measure turbidity?

The correct requirement for how often each filter's turbidimeter must be able to measure turbidity is every 15 minutes. This frequency ensures that operators can closely monitor the effectiveness of the filtration process and quickly identify any issues that may arise, such as an increase in turbidity which could indicate that the filter is becoming overloaded or that there may be a problem with the filtration system. Continuous monitoring helps maintain water quality and complies with water treatment regulations, allowing for timely intervention when necessary. Regular measurements every 15 minutes offer a balance between operational efficiency and the need for sufficient data to track changes in water quality effectively. This is crucial for the operational integrity of water treatment facilities and protecting public health.