What is NOT one of the five major sludge waste applications commonly practiced?

Composting is not typically classified as one of the five major sludge waste applications commonly practiced. The primary methods for managing sludge include incineration, land application, ocean disposal, and others.

Incineration involves burning sludge to reduce its volume and destroy pathogens. Land application refers to the practice of spreading treated sludge on agricultural land, where it can act as a fertilizer and soil conditioner. Ocean disposal involves discharging treated sludge into ocean waters, a practice that can be controversial due to potential environmental impacts.

Composting, while a method for organic waste management that can include some forms of biomass and green waste, is not primarily associated with the management of sludge. In the context of sludge management, it is less recognized as a mainstream practice compared to the others listed.