How long should water be collected after the Fossett has run to adequately flush out the service line?

The correct choice emphasizes the importance of adequately flushing the service line to ensure that any stagnant or potentially contaminated water is removed before the water is used. When flushing a service line, the objective is not solely to meet a specific time limit but rather to ensure that fresh, clean water reaches the point of use. Factors such as the length of the service line and the flow rate must be considered to determine the appropriate duration for flushing.

While the other options suggest specific timeframes, they do not take into account the variability in systems based on factors like pipe size, flow velocity, and volume of water needed for effective turnover. Thus, flushing should continue until it is clear that any residual or stagnant water has been fully replaced by fresh water from the main supply. By focusing on the goal of thorough flushing rather than a preset timeframe, the chosen answer aligns with best practices for water quality and safety.