When must repeat samples be collected after a positive coliform result?

Repeat samples must be collected within 24 hours after a positive coliform result to ensure timely monitoring and response to potential contamination in the drinking water supply. This prompt action is critical because coliform bacteria are indicators of fecal contamination and can pose serious health risks.

Collecting repeat samples within this timeframe allows water system operators to quickly assess the ongoing quality of the water, identify the source of the contamination, and take necessary corrective actions if further positive results are found. This timeframe is aligned with standard health guidelines and regulatory requirements aimed at protecting public health, highlighting the need for rapid response in monitoring drinking water safety.