Which statement regarding surface and groundwater is true?

The statement that both surface and groundwater can be assessed based on sanitary conditions and the importance of surveying entire watersheds for surface water supplies provides important information regarding water quality management.

Surface water sources, such as rivers and lakes, are often at risk for contamination due to their exposure to environmental factors, leading to a general assumption that they require careful management. While not all surface water is unsanitary, it is prudent to treat it with caution until its quality can be confirmed. Therefore, stating that all surface water must be considered unsanitary highlights the need for rigorous testing and monitoring in environmental health practices.

Additionally, for effective management of water resources, entire watersheds should be surveyed. This includes evaluating the entire area that drains into a particular body of surface water, as various factors within the watershed can contribute to the water quality. This holistic approach ensures that any potential sources of contamination are identified and managed properly.

Thus, the combination of recognizing the risks associated with surface water and the necessity of watershed surveys supports the assertion that both of these concerns are valid and emphasizes the role of environmental health specialists in water quality management.