In the event you are notified that a coliform sample was positive, how many hours do you have to obtain a repeat sample?

When a coliform sample tests positive, the regulatory requirement mandates that a repeat sample be collected within 24 hours. This timeframe is crucial for ensuring that any potential contamination is promptly investigated and addressed.

The 24-hour window allows water operators to act quickly, which is essential for protecting public health. Timely follow-up sampling helps to confirm whether the initial positive result was an anomaly or if there is an ongoing issue within the water system. Delays beyond this period could compromise the safety of the water supply and hinder an effective response to contamination.

In contrast, shorter periods such as 8 or 12 hours may not be sufficient for logistics and compliance, while a longer timeframe like 48 hours does not align with the urgency required in public health interventions regarding water quality.