What is required for the installation of a dishwasher in terms of its waste piping?

For the installation of a dishwasher in terms of its waste piping, it is required that the waste be piped indirectly through the sink. This method is important for preventing backflow and ensuring that wastewater from the dishwasher does not contaminate the potable water supply or other plumbing fixtures. By connecting the dishwasher indirectly through the sink, typically via an air gap or a standpipe, it creates a physical separation that allows air to break the siphon effect that could lead to backflow. This is a safeguard built into plumbing codes to protect public health and the integrity of the plumbing system.

In this context, choices that involve direct connections to waste lines, like connecting directly to existing waste lines, are not compliant with plumbing codes as they pose a risk of contamination. Similarly, while traps and check valves may be part of a drainage system, they do not specifically address the requirement for an indirect waste connection for dishwashers. Therefore, the indirect piping requirement through the sink is the correct response in line with Omaha Plumbing Code and general plumbing safety practices.