Which method is most commonly used for collecting water samples?

The grab sampling method is the most commonly used technique for collecting water samples due to its straightforward and practical approach. In this method, a single sample is taken at a specific point in time, which makes it ideal for quickly assessing water quality at a particular location and moment. This technique is especially useful in situations where immediate analysis is required, such as during pollution events or routine monitoring of water quality parameters.

Grab sampling is versatile, allowing for the analysis of a wide variety of contaminants and water quality indicators. Additionally, it is time-efficient and does not require complicated equipment, making it accessible for many water quality assessment scenarios. While other methods like composite sampling or continuous sampling have their own applications and advantages, grab sampling is favored for its simplicity and the immediate insights it can provide into the state of a water body at a given moment.