Final answer:
A cross-connection is a physical link between sources of safe and dirty water, which is crucial to prevent to ensure the supply of clean drinking water.
Step-by-step explanation:
The correct answer is option D: Physical link between sources of safe and dirty water. A cross-connection in the context of water supply is a connection where contaminated water can enter the potable water supply. It is important to prevent such connections to preserve the quality of drinking water, as a compromised water supply can lead to diseases. Safe practices and devices such as backflow preventers are essential for protecting water integrity. The clean drinking water that flows from a faucet is the result of a well-managed water distribution system that avoids cross-connections, ensuring that the water remains suitable for consumption and other uses.
This can occur due to faulty plumbing arrangements, such as pipes connected incorrectly or in close proximity to each other.
A cross-connection poses a significant risk to public health as it can lead to the contamination of the safe water supply. For example, if there is a cross-connection between a drinking water supply and a wastewater pipe, the wastewater can enter the drinking water supply and cause waterborne diseases.
In order to prevent cross-connections and ensure the safety of the water supply, various measures are taken, such as the installation of backflow prevention devices, regular inspections, and adherence to plumbing codes and regulations.