What is a hydrant used for in water distribution?

A hydrant plays a crucial role in water distribution by serving as a point of access for emergency services, particularly for firefighting purposes. Fire hydrants are specifically designed to allow firefighters to quickly connect their hoses to the municipal water supply in order to combat fires effectively. They also provide access for maintenance activities, ensuring that sections of the water distribution system can be flushed or inspected as necessary without disrupting the entire system.

The other choices, while they address aspects of water distribution, do not accurately describe the primary function of a hydrant. For instance, cleaning residential pipelines is typically done through different methods and equipment that do not involve hydrants directly. Measuring water pressure is performed with specific devices designed for that purpose and not through hydrants. Additionally, filtering impurities from the water is part of the treatment process that occurs at water treatment facilities, not at the hydrant level. Therefore, option A encompasses the main functions of a hydrant in the water distribution system effectively.