Fats, Oils & Grease (FOG)
Grease Trap Requirements
Grease traps are plumbing fixtures installed on the interior of the building (above or below the floor line) that collect fats, oils, and grease (FOG) discharged into the waste drainage system (gray water) from sinks and other grease producing fixtures. The purpose of a grease trap is to protect downstream pipes and the City's sewer system by providing enough retention time to allow the FOG to separate from the water and accumulate at the top of the grease trap where it can be periodically removed and discarded along with other solid wastes.
The size of the grease trap is based on the number, type, and flow rate of plumbing fixtures to be connected to the trap. All grease traps must be approved by the city. For approval email the Pretreatment coordinator Dee Russell or call 360-330-7512 for grease trap sizing requirements.
Business Owner Responsibilities for Grease Trap Cleaning & Maintenance
- Each food service business shall be solely responsible for the cost of grease trap installation, inspection, cleaning and maintenance. A business may contract with a grease hauler for cleaning or the business can perform cleaning and waste removal themselves provided the maintenance schedule is properly documented.
- Cleaning and maintenance shall be performed on a routine schedule such that the total volume of captured grease and settled solid material never displaces more than 25% of the total volume of the unit. The cleaning frequency shall be at least every week unless an alternate schedule is approved by the City.
- Grease and solid materials removed from a grease trap shall be bagged and disposed of as solid waste.
- Fats, Oils and Grease Maintenance Log (PDF) shall include the date and time of all cleaning and maintenance of each grease trap. Such records shall be available for inspection by City personnel on demand and kept in a log to be submitted to the City annually.
Grease Interceptor Requirements
Grease Interceptors are installed on the exterior of the building and are designed for the removal of fats, oils, and grease (FOG) in order to protect downstream piping and the public sewer system. Interceptors are required for restaurants, commercial kitchens, school kitchens, grocery stores, hospitals, and other facilities where FOG may be introduced into the system.
The minimum sized Grease Interceptor per City Code is 1,000 gallons available from Oldcastle Grease Interceptor (PDF) approved equivalent, submit all specs to the City for approval.
Business Owner Responsibilities for Interceptor Cleaning & Maintenance
- Each food service business shall be solely responsible for the cost of grease interceptor installation, inspection, cleaning and maintenance.
- Businesses shall contract with an approved grease hauler to perform cleaning. Pumping services shall include the complete removal of all contents, including floating materials, wastewater and bottom solids. Decanting or discharging of liquid waste back into the grease interceptor is strictly prohibited. View a list of FOG Service Providers (PDF), for the City of Centralia, for services that pump out and/or recycle your grease interceptor waste.This list is not meant to be all-inclusive. The City makes no recommendations regarding private firms providing fats, oils, and grease removal and recycling services.
- Each business is responsible for maintaining the grease interceptor in good functioning order.
- The business shall maintain records of the date and time of all cleaning and maintenance and shall make this record available for inspection on demand and kept in a log to be submitted to Centralia Public Works annually,1100 North Tower Avenue, Centralia, WA 98531 (no later than December 31, of each year or a violation may occur.)
- Cleaning and maintenance are required to be performed on a routine schedule such that the total volume of captured grease and settled solid material never displaces more than 25% of the total volume of the unit. The cleaning frequency shall be at least once every 90 days unless an alternate schedule is approved by the City.