Why is surface water commonly used in public supply systems?

Surface water is commonly used in public supply systems primarily because it is usually less expensive to collect. This is largely due to the fact that surface water sources, such as rivers, lakes, and reservoirs, are typically more accessible than groundwater sources. Collecting surface water often requires less investment in drilling wells or pumping equipment, which can significantly reduce overall costs for municipalities. Additionally, the infrastructure needed to transport water from surface sources is often more straightforward and less costly to implement.

While it is true that some surface water sources may require treatment to meet safety and quality standards, the costs associated with collection and treatment can still be more economical compared to managing deeper groundwater sources. This economic efficiency makes surface water an attractive option for many public supply systems, particularly in regions where surface water resources are plentiful.