What situation necessitates the use of a pail latrine?

A pail latrine is specifically designed for circumstances where traditional digging for a latrine is not feasible. This is often the case when the water table is too close to the surface, as excavation could lead to contamination of the groundwater with waste. Pail latrines offer a sanitary and practical alternative in these environments by allowing waste to be collected in a sealed container, which can then be properly disposed of without the risk of polluting local water sources.

While other situations, such as remote locations or specific environmental regulations, might present similar challenges or considerations, they do not specifically necessitate the use of a pail latrine. The fundamental issue that dictates the need for a pail latrine is the inability to dig a proper latrine due to the proximity of the water table. Therefore, understanding this context clarifies why the given answer is appropriate for this question.