What is the maximum time recommended to wait before analysis of coliform bacteria samples?

• A. 2 hours
• B. 4 hours
• C. 6 hours
• D. 8 hours

Answer: (D)

The recommended maximum time to wait before analyzing coliform bacteria samples is 8 hours. This timeframe is essential because coliform bacteria can grow or die off depending on conditions such as temperature and nutrient availability. Delaying analysis beyond this period can lead to misleading results and inaccurate assessments of water quality.

If samples are held for too long before analysis, it may result in an underestimation of coliform levels due to die-off or an overestimation if any bacteria were to proliferate during storage. To ensure that the analysis reflects the true conditions of the water being tested, adhering to the 8-hour limit is crucial. This practice is part of standard protocols to maintain the reliability of microbiological testing in water treatment.