What issues does a worn meter cause in water usage measurement?

A worn meter can lead to inaccuracies in water usage measurement, and one of the most common issues is that it under registers the amount of water being used. This means that the meter does not record the total volume of water consumed, resulting in a lower reading than what is actually being used. This can occur for various reasons, such as wear and tear on the mechanical components of the meter or sediment build-up that may affect its ability to accurately measure flow.

Under registering can create problems for both the water utility and the customer. For the utility, it may lead to reduced revenue since customers are being charged for less water than they actually use. For customers, it can result in unexpected charges later if adjustments are made based on accurate readings, creating potential disputes or dissatisfaction.

The other options present different scenarios that do not apply to a worn meter. Accurate measurements of all flows is not possible if the meter is malfunctioning, shutting off service automatically is not a characteristic of a worn meter, and over registering would mean the customer is charged for more water than they use, which typically occurs due to different types of meter issues, not necessarily wear. Thus, the most accurate description of the issue caused by a worn meter is its tendency to under register water usage.