What is a bad way of taking groundwater samples?

Taking groundwater samples is crucial for understanding its quality, but certain methods can lead to less reliable data. The percolation test is primarily designed to assess how quickly water moves through soil, which is important for construction and wastewater management, but it does not provide an accurate representation of groundwater quality at a specific point in time. Instead, it measures the soil's ability to absorb water rather than the actual characteristics of the groundwater itself.

In contrast, grab samples, pumped samples, and composite samples are all methods used to evaluate groundwater quality directly. Grab samples provide a snapshot at a single point in time, pumped samples involve extracting water from a well to analyze it, and composite samples aggregate multiple samples over time to get an overall picture of groundwater quality. Therefore, the percolation test is not suited for sampling groundwater, making it an inappropriate method in this context.