Which type of water is primarily handled by a drain?

The correct answer is waste water, as this type of water consists of used or contaminated water that has been discharged from various sources, such as sinks, toilets, showers, and industrial processes. In plumbing systems, drains are specifically designed to remove this water from buildings and transport it to sewage treatment facilities or septic systems for proper disposal and treatment.

Potable water refers to water that is safe for human consumption and is typically supplied through pressurized pipes to faucets and other fixtures. Fresh water, while it can also refer to naturally occurring water sources, does not specifically relate to the plumbing system's waste management function. Storm water is the runoff that occurs from precipitation, which requires separate management strategies, often involving drainage systems distinct from those intended for waste water. Thus, the primary role of a drain is to handle and efficiently remove waste water, ensuring sanitation and public health.