What is the hold time for fecal coliform samples?

The hold time for fecal coliform samples is indeed 8 hours. This short timeframe is critical because fecal coliforms are an indicator of recent contamination and their presence can change rapidly over time due to environmental factors. Therefore, it is essential to process or transport the sample to the laboratory within 8 hours to ensure that the results accurately reflect the water quality at the time of sampling. Beyond this period, the viability of the coliform bacteria may decline, leading to unreliable test results.

In contrast, longer hold times, such as those suggested by the other options, would not be appropriate as they could compromise the accuracy of the fecal coliform analysis. Each of the other timeframes exceeds the established standard for maintaining sample integrity, making them unsuitable for this type of analysis. Thus, adhering to the 8-hour hold time is crucial for accurate and reliable water quality assessments related to fecal contamination.