Where should repeat Total Coliform tests be collected?

The correct answer emphasizes the importance of pinpointing contamination sources in the distribution system. When total coliform tests yield a positive result, it's crucial to conduct repeat testing at the same tap. This approach enables water treatment professionals to verify if the contamination is localized to that specific tap or if it's present in the surrounding service connections. Testing up to five service connections from the location of the positive result allows for an adequate assessment of potential contamination spread within that area.

By focusing on the same tap and nearby service connections, personnel can effectively trace the origin of the contamination, evaluate the quality of the water being delivered, and implement necessary corrective actions. This targeted approach is much more effective than collecting samples from unrelated sources since those results may not accurately reflect the issue at hand.

Other options would not provide the same level of clarity or assurance regarding the specific contamination incident, making option A the most suitable choice for ensuring water safety and compliance.