Grease Traps

Fats, Oils, and Grease (FOG)

Fats, Oils, and Grease (FOG) in sanitary sewage will stick to the inner surface of pipes and build up over time. FOG hardens as it oxidizes and can become very difficult to remove. Unless steps are taken to prevent buildup, FOG can cause blockages. Blockages can occur in the internal plumbing or the lateral serving a building, causing backups of sewage in the building and costly repairs and remediation for the property owner. Blockages can also occur in the public sewer causing backups in buildings, overflows in the street, and loss of sewer service to upstream homes and businesses. Sanitary sewer overflows can have significant detrimental public health and environmental impacts. The Sewer Department spends considerable time and effort to prevent blockages in the public sewer by regularly cleaning pipes affected by FOG. You can help too by stopping FOG at the source. 

Most FOG in residential and commercial settings comes from cooking and subsequently from cleaning cookware and tableware. Scraping and dry-wiping excess FOG and other solids from pots, pans, utensils, and dishware before washing can greatly reduce your chances of FOG related issues. Excess FOG and food solids should be disposed of in the garbage or compost. Allow FOG to cool to room temperature before disposing of it in the garbage or compost if necessary. Fats, Oils, and Greases should never be poured down the drain. Dish soap doesn't prevent FOG from building up in pipes. Even oils that are liquid at room temperature will build up in pipes and harden over time. 

Grease Traps

Restaurants, cafeterias, and other commercial establishments that produce larger amounts of FOG are required to use grease traps (including grease interceptors) to prevent FOG from building up and causing blockages. Grease traps are designed to separate FOG and other solids from the wastewater stream. It's important that grease traps are used and maintained properly so they function according to design. Grease traps should be cleaned to remove accumulated FOG and solids before 75% of the volume of the grease trap is full or more frequently as necessary to ensure the grease trap is working properly. Water above 140° F, surfactants, solvents, or emulsifiers should never be allowed into a grease trap because they can interrupt the proper function of the grease trap and cause FOG to bypass the trap and contribute to blockages downstream.

The Sewer Department routinely performs grease trap inspections to ensure grease traps are being used and maintained properly. Inspections are conducted annually or more frequently as necessary. Grease trap inspection appointments may be made for 8:00 AM, 9:00 AM, 10:00 AM, 11:00 AM, or 1:00 PM, Monday through Friday. Inspections should be scheduled at least one week ahead and are on a first-come-first-served basis. Grease trap inspections should be scheduled at the same time the grease trap is being cleaned or as soon as possible afterwards. Please use the form below to request a date and time for your next inspection that coincides with your regular cleaning schedule. Sewer Department staff will contact you to confirm your appointment if the requested appointment time is available.

A manager or other staff member must be on site to meet the Sewer Department inspector and open the grease trap. Maintenance and cleaning logs and cleaning/disposal invoices must be made available to the Sewer Department inspector at the time of the inspection. 

Please review the Grease Trap section of the Municipal Code before your next inspection.