Final answer:
The major maintenance concern with open-top drains is the use of strong alkali drain cleaners, which can cause severe burns, contribute to pollution, and lead to pipe damage due to heat generation and pressure buildup from gas generation.
Step-by-step explanation:
The major maintenance concern with open-top drains involves the use of strong chemical cleaners, such as strong alkali drain cleaners which are known to cause severe hazards like burns and disfigurement. For instance, a woman and a small girl encountered serious injuries due to accidents involving concentrated lye and a common lye drain opener, respectively.
These drain cleaners not only pose a risk to health and safety but also contribute to environmental pollution, as they are flushed into the water supply. Furthermore, the heat generation from these chemical reactions can soften plastic PVC pipes, while the gas generation can lead to pressure buildup, potentially causing older pipes to burst. This illustrates that commercial chemical-based solutions can lead to severe corrosion and other forms of damage to pipes and sewer lines.