Maintaining minimum operating pressure in the distribution system helps to prevent which of the following?

Maintaining minimum operating pressure in the water distribution system is critical for preventing backflow contamination. When the pressure in the distribution system drops below a certain level, it can create a vacuum effect or a negative pressure condition. This pressure change can allow water from non-potable sources or contaminated areas to flow back into the potable water supply, leading to backflow contamination. By ensuring that there is always adequate pressure in the system, utilities can effectively mitigate the risk of contaminants entering the drinking water supply and protect public health.

While customer complaints, waterborne diseases, and cross connections are important considerations in water system management, they are not directly related to the specific threat posed by backflow contamination. Customer complaints might stem from issues like low flow or service interruptions, waterborne diseases are typically associated with inadequate treatment processes, and cross connections involve physical links between potable and non-potable systems rather than pressure conditions specifically. Thus, the focus on pressure maintenance directly correlates with the prevention of backflow contamination.