What is unlawful regarding sewage systems?

The correct response highlights that operating a sewage system without following the relevant Act constitutes an unlawful practice. This is significant because regulations surrounding sewage systems are established to protect public health, the environment, and the integrity of local infrastructure. These regulations ensure that systems are designed and maintained properly, preventing hazardous conditions that could arise from non-compliance. Adhering to the specified Act is essential for the safe and efficient operation of sewage systems, making this option the valid one.

In contrast, while the lack of approval from the chief building official can raise concerns, the specific requirement to follow the overarching Act is a broader legal obligation that supersedes individual approvals. Similarly, while maintaining a sewage system according to local codes is important, failing to do so does not directly violate the statutory framework governing sewage systems. Lastly, although engaging a structural engineer may be critical for ensuring safety and compliance during construction, this is not necessarily unlawful in all contexts unless regulations specifically mandate such involvement for sewage systems.