Approximately what percentage of public water systems utilize surface water?

The correct answer is 40%. This figure reflects the significant role that surface water plays as a source for public water systems. Surface water, which includes rivers, lakes, and reservoirs, is utilized widely because it can be more easily accessed and treated compared to groundwater in many regions.

The reliance on surface water is especially prominent in urban areas where population density creates a higher demand for water supply. Furthermore, surface water sources are often replenished over time through rainfall, making them sustainable options for many communities.

While other percentages represent varying levels of surface water usage in different contexts, 40% is recognized as an established estimate for public water systems across many jurisdictions, reflecting both historical data and current practices in water supply management. Understanding this statistic helps to highlight the importance of both managing surface water resources effectively and considering their impact on overall water quality and availability.