What should homeowners avoid flushing down the toilet to maintain septic health?

Homeowners should avoid flushing harsh chemicals and non-biodegradable items down the toilet to maintain septic health because these substances can disrupt the natural biological processes essential for the functioning of a septic system.

Septic systems rely heavily on bacteria and microorganisms to break down waste. Harsh chemicals, such as bleach, disinfectants, and other household cleaners, can kill these beneficial organisms, leading to poor breakdown of septic waste and, ultimately, system failure. Non-biodegradable items, such as plastics, feminine hygiene products, and paper towels, do not decompose in the septic tank and can cause blockages in the pipes and drain field. This can lead to backups, costly repairs, and environmental harm as the system fails to function effectively.

In contrast, human waste and toilet paper are specifically designed to be processed by septic systems, and while biodegradable items and food scraps might seem like they would break down, they can still disrupt the balance if not managed properly. Flushing only liquids and natural materials is also too restrictive, as it neglects the fact that certain solids, like toilet paper, are acceptable in moderation. Thus, the correct answer emphasizes the avoidance of materials that can disrupt the septic system's biological function.