What is a recommended action when there is a positive test result from a distribution sample?

When a distribution sample yields a positive test result, it indicates the potential presence of harmful bacteria or contaminants in the water supply, which can pose significant health risks to consumers. Therefore, the recommended action is to notify the public and arrange for retesting. This approach is crucial for maintaining public safety and trust, as immediate communication ensures that those affected are aware of the situation and can take necessary precautions.

In addition to notifying the public, arranging for retesting serves to confirm whether the initial positive result was a true positive or a false positive, ensuring that appropriate measures can be implemented based on accurate information. This dual action demonstrates a responsible and proactive approach to safeguarding water quality and public health.

Other options would not appropriately address the situation. For example, reducing chlorine levels or increasing water temperature could exacerbate the problem rather than solve it, and ignoring the result dismisses the potential health risks involved. Thus, notifying the public and retesting is the most appropriate and responsible action following a positive test result.