The outlet pipe in a grease interceptor shall originate within ____________ of the tank bottom.

In a grease interceptor, the outlet pipe's placement is crucial for the efficient operation of the system. The code specifies that the outlet pipe must originate from a specific distance above the tank bottom to ensure proper management of grease and other waste materials.

The correct requirement is that the outlet pipe should be positioned no more than 8 inches above the bottom of the tank. This distance is significant because it helps to maintain a sufficient volume of grease and waste in the tank while preventing the potential for solids to escape, which could disrupt the plumbing system downstream. Keeping the outlet at this distance allows for the effective separation of grease from wastewater, ensuring that only the clarified effluent flows out, which minimizes the likelihood of clogging in the sewer lines.

The other options present distances that are either too short or too long, which do not adhere to the necessary operational efficiency stipulated by the plumbing code. Maintaining the outlet at exactly 8 inches maximizes the interceptor's performance by striking a balance between effective grease capture and permitting the outflow of clarified wastewater.