Grease Trap 


Fat, Oil and Grease (FOG)

Fat, oil and grease (FOG) are a major cause of preventable sanitary sewer blockages and overflows that can cause health hazards, damage homes and businesses and threaten the environment. 

Food Service Establishments generate FOG through normal kitchen activities.  Fat, oil and grease are common and can be found in items such as meat, food scraps, cooking oils, shortening, lards, dairy products, salad dressings, and butter/margarine and are commonly washed into the plumbing system through the sink during clean-up in the kitchen.  

FOG is an issue, because it doesn’t dissolve in water. When it enters the plumbing that discharges directly into the collections system, it can decrease pipe capacity when it cools down by coating the inside of drain pipes, causing slow drainage, and eventually blocked pipes both within the Food Service Establishments internal plumbing and the Subregional  Wastewater Collection System.  

Program Overview

Food Service Establishments include all restaurants, fast food establishments, caterers, bakeries, donut shops, halls and auditoriums with kitchens, and any other businesses that do commercial cooking or food preparation.

The City of Santa Rosa Utilities Department Environmental Compliance Section regulates, inspects, and permits all Food Service Establishments within the Santa Rosa Subregional Water Reclamation System. The FOG program encompasses Food Service Establishments located in the cities of Santa Rosa, Rohnert Park, Sebastopol,  Cotati and the South Park County Sanitation District who are our Subregional partners.   

The existing program has been an element of the City of Santa Rosa Non-Residential Source Control Program which was initiated in 1986. 

In 2006, the California State Water Quality Board finalized their statewide approach to reducing sanitary sewer overflows and passed Order No. 2006-003, the Statewide General Waste Discharge Requirement (WDR) for Wastewater Collection Agencies.  This WDR requires that all owners/operators of sanitary sewer collection systems develop a Sanitary Sewer Management Plan (SSMP).  A FOG Control Program is one of the elements that is now mandated in the State of California to be incorporated within the SSMP.

Program Objectives

The FOG Source Control Program objectives have remained the same since its initial implementation.  They include:

• Reducing the amount of FOG entering the Subregional Collection System and the   Laguna Water Reclamation Facility originating from Food Service Establishments.

• Protecting the environment by eliminating FOG related collection system backups and overflows.

• Eliminating storm water pollution sources associated with non-permitted outdoor Food Service Establishment activities such as washing kitchen mats and restaurant equipment and other maintenance activities in outdoor areas that discharge to the Storm Water Collection System.

• Continuing to comply with the City of Santa Rosa, the State of California, and other applicable Federal regulatory requirements and with other City goals and objectives.

Grease Removal Devices

All Food Service Establishments that discharge wastewater to the Subregional Wastewater Collection System are required to have City approved and properly sized grease removal device also commonly referred to as “grease traps” or “grease interceptors”. 

Both devices are primary grease removal devices that are designed and work in the same way, by separating and retaining free-floating fat, oil and grease (FOG).  The difference between the two types of grease removal devices is basically the size and physical location of the unit.  Grease interceptors are larger units (with a capacity of 800 gallons and larger) that are typically located in-ground and outside of the building’s exterior.  Grease traps are much smaller units, typically located inside the kitchen directly under the sink(s).   

Minimum Grease Removal Device Sizing Requirements

In all cases of redevelopment and new construction, staff from the Environmental Compliance Section will review and must approve the type and sizing of any proposed grease removal device(s) during the plans approval stage, before a plumbing permit will be issued by the Building Department within the jurisdiction of the City of Santa Rosa or the other Subregional partner where the Food Service Establishment is proposed to be located.


Grease Trap
Grease Trap

 Important Documents