What must be considered for cross-connection control in plumbing?

When considering cross-connection control in plumbing, the primary focus is on the potential for backflow contamination. Backflow occurs when water from a non-potable source flows back into the potable water supply, which can lead to serious health risks due to the introduction of contaminants. Ensuring that there are measures in place to prevent backflow is critical for the safety of drinking water.

Controlling cross-connections involves using devices such as backflow preventers and vacuum breakers, which are designed to stop the reverse flow of water. This is essential in applications where potable and non-potable waters may interact, ensuring that safe drinking water is not compromised. Therefore, understanding the threats posed by backflow is fundamental in plumbing practices that safeguard public health.

The other options, while relevant to plumbing in various contexts, do not address the specific concerns associated with cross-connection control as directly as backflow contamination does. For example, variations in water pressure can impact system performance but do not directly cause contamination in the same manner as backflow can. Similarly, pipe sizing and water temperature regulations are important aspects of plumbing design and function but do not pertain specifically to cross-connection control.