At which locations can compliance sampling occur?

Compliance sampling can occur at both the point of entry and the point of use, making this the correct choice. The point of entry refers to the location where water enters a distribution system, which is critical for testing the quality of water directly as it is treated and before it is distributed. On the other hand, the point of use represents the location where water is utilized by consumers, such as households or businesses. Testing at the point of use is essential for evaluating the water quality that consumers actually experience, which can reflect any changes that may occur in the distribution system or due to household plumbing.

This approach is fundamental in ensuring that the water meets safety and quality standards dictated by regulatory authorities. Such sampling practices help verify compliance with health and safety regulations, monitoring contaminants that may arise through various stages of the water delivery system. Therefore, conducting compliance sampling at both of these critical locations enables comprehensive oversight of water quality from source to consumption.