What is a major consequence of bladder failure in a storage tank?

Bladder failure in a storage tank primarily leads to air mixing with water, which can have significant implications for the water quality and system performance. When the bladder within the tank fails, it can allow air to enter the water supply. This can introduce oxygen into the system, leading to potential issues such as oxidation of iron and manganese, which can subsequently cause staining and other quality concerns. The presence of air in the water could also cause disruption in the delivery system, compromising efficiency and leading to noisy plumbing or tank issues.

The other options do not directly relate to the consequences of bladder failure. For instance, increased efficiency, enhanced disinfection, and improved pretreatment are typically associated with a properly functioning system rather than being outcomes of a malfunction. Air mixing with water due to bladder failure poses real, tangible risks to water quality, making it the most consequential outcome in this scenario.