What does a hydrogeologic barrier do?

A hydrogeologic barrier serves to prevent the movement of contaminants, including pathogens, from one area to another, particularly into water supplies. This is crucial for protecting groundwater sources and ensuring the safety of drinking water. By blocking or slowing down the flow of undesirable substances, a hydrogeologic barrier helps secure the integrity of water quality, thereby safeguarding public health.

In the context of water systems, the presence of such barriers is vital for maintaining clean and safe water sources. Effective hydrogeologic barriers can be natural formations, such as clay layers, or engineered solutions designed to create a protective environment around water supply sources. These barriers are an essential component in the management of water resources, especially in areas vulnerable to contamination.

The other options do not accurately describe the primary function of a hydrogeologic barrier. For instance, enhancing water flow or purifying water chemically speaks to different processes in water management and treatment that involve altering or improving water characteristics rather than preventing contamination. Temperature control relates to the management of water conditions but does not pertain to the barrier's role in protecting against pathogens.