If a water sample tests positive for coliforms, how soon must repeat samples be collected?

When a water sample tests positive for coliforms, it indicates a potential contamination issue, which may pose health risks to consumers. The standard requirement is to collect repeat samples within 24 hours of the initial positive result. This timeframe is crucial as it allows for prompt investigation and remediation if contaminants are found. By taking these follow-up samples quickly, operators can assess whether the contamination is an isolated incident, a temporary spike, or indicative of a more systemic problem in the water supply. Quick action helps to ensure the safety of the water for public consumption and allows for efficient decision-making regarding the necessary corrective actions.