Which of the following should not be flushed down a septic system?

The choice regarding non-biodegradable products like wipes and grease is essential because these materials can have detrimental effects on septic systems. Septic systems rely on natural biological processes to break down waste, and the introduction of non-biodegradable items disrupts these processes. Wipes, regardless of being labeled as "flushable," do not break down effectively in water and can accumulate, leading to clogs and potential system failure.

Grease poses another significant problem; it can solidify within the tank or in the drain field, creating blockages that impede the flow of wastewater and the performance of the entire system. Maintaining a healthy septic system requires the proper disposal of certain materials to ensure that the tank functions efficiently and to extend its lifespan. Thus, avoiding these non-biodegradable products is crucial for the effective functioning of septic systems.