What is a recommended practice when storing collected water samples?

Refrigerating collected water samples until they are delivered is a recommended practice because it helps to preserve the viability of the microorganisms present in the sample. Legionella bacteria, for instance, can grow or die off if the samples are not kept at appropriate temperatures. By keeping the samples cool, specifically in the refrigerator, the conditions that inhibit bacterial growth are maintained, thereby ensuring that the samples remain representative of the water source being tested.

This method is critical for accurate analysis and helps ensure that any Legionella present in the sample can be detected during testing. In contrast, other options, such as storing samples at room temperature or in direct sunlight, could lead to changes in the bacterial population, potentially causing false results or misinterpretation of water quality. Allowing samples to evaporate would not only alter their concentration but could also affect the microbial community, leading to unreliable results. Therefore, maintaining the integrity of water samples through refrigeration is essential for accurate water quality assessments.