What is the most likely cause of drop in pressure for customers living in higher elevations?

When considering the impact of elevation on water pressure, living on a hill directly affects the pressure experienced by customers. As elevation increases, the weight of the water column above decreases, resulting in lower water pressure delivered to consumers. This phenomenon is due to gravity, where water naturally seeks to flow downhill. In elevated areas, the water must be pumped from a lower source, and by the time it reaches higher elevations, the pressure can decrease significantly.

The other options do not directly address the foundational principle of how elevation influences water pressure. For instance, while faulty equipment or increased distance from the water source could lead to pressure loss, these are not inherent to the geographical elevation itself. Similarly, while higher demand could strain a system, it is not specifically tied to living on a hill. Thus, the most direct and impactful reason for a drop in pressure at higher elevations is indeed the physical aspect of living on a hill, which affects water pressure due to the gravitational pull on the water column.