Grease Trap Requirements

Fats, oil, and grease, or FOG, can clog sewer lines. For this reason, Charleston Water System requires food service establishments that are connected to our sewer system to install and maintain a grease trap in accordance with our specifications.

Our Wastewater Collection Department reviews and approves grease trap plans, inspects traps after installation, and conducts periodic inspections of grease traps. For complete information about our grease trap requirements, including diagrams, forms, etc., please review the Grease Trap and Grease Interceptor Standards.

Overview of Requirements for Food Establishments

  • Complete the Grease Trap/Interceptor Application Form (page 18 of the Grease Trap Standards) and submit it along with plans, specifications, plumbing diagrams, riser diagrams, etc.
  • After receiving an approval letter from CWS, install the grease trap.
  • Contact CWS to schedule an inspection.
  • Keep a Maintenance Log record. Grease traps/interceptors must be thoroughly pumped out and/or cleaned at least four times a year, or at a frequency determined by the CWS Inspector.


  • Application Fee: $25  
  • Inspection Fee: $50
  • Re-inspection Fee: $50
Application to Install a Grease Interceptor

Grease traps that are found to be unsatisfactory during an inspection will be required to be re-inspected.

For more information or questions contact the Wastewater Collection Department at 843-308-8277 or 843-308-8299.