Journeyman Plumber ExamDrainage, Waste, and Venting (DWV) SystemsEasy

A plumber is installing a floor drain in a commercial kitchen. The drain is subject to heavy grease discharge. What type of interceptor is required to prevent grease from entering the building's drainage system?

  1. ALint interceptor
  2. BSand interceptor
  3. COil separator
  4. DGrease interceptor
Show answer & explanation

Correct answer: D. Grease interceptor

Commercial kitchens are known for producing significant amounts of grease. A grease interceptor is specifically designed to separate and retain fats, oils, and greases (FOG) from wastewater before it enters the public sewer system.

Why the other options are wrong

  • A. Lint interceptors are used for laundries or places with fibrous waste, not grease.
  • B. Sand interceptors are used for situations where sand or other heavy solids are present, such as car washes or garages.
  • C. Oil separators are used for petroleum-based oils, typically in automotive or industrial settings, not cooking grease.

Grease Interceptor

A plumbing device designed to intercept and retain fats, oils, and greases (FOG) from wastewater before they enter a sanitary sewer system, preventing blockages and environmental contamination.

  • Required for commercial kitchens.
  • Separates FOG by buoyancy.
  • Must be regularly cleaned.
  • Protects public sewer lines.

Memory trick: Interceptors Catch Specific Waste, Keeping Drains from a Nasty State.

More Drainage, Waste, and Venting (DWV) Systems questions