Fats, Oils and Grease Management Best Practices for Waste Water

Protecting the public health and environment are the goals of fats, oil and grease, or FOG, ordinances. Fats, oil and grease accumulation is one of the two most significant contributors to sewer overflows. The most cost-effective way to protect the sewer system from the effects of FOG is to change kitchen practices in order to catch FOG at the source.

FOG is a byproduct that food service establishments must constantly be aware of and manage. Best management practices minimize FOG discharge into the sewer system and keep users in compliance with the city ordinance.

The most important thing you can do to help extend the length of time between maintenance and save your facility in maintenance expense is to use diligence in dry clean-up prior to wet clean-up. Scrape food debris in the garbage and dry-wipe the dishes prior to immersion in hot water (sink or dishwasher).

Best Management Practices

Best management practices that should be implemented at food service establishments:

• Provide regular training to employees.
• Limit or discontinue use of the garbage disposal and dispose of food waste in the trash or compost.
• Scrape food waste into the compost or trash, and dry-wipe cookware and utensils prior to washing.
• Do not pour fryer oil or grease down the drain.
• Use fine-mesh drain screens.
• Place “No FOG” signs near all sinks.
• Place best management posters near sinks or on employee bulletin boards.
• Inspect and clean grease traps and interceptors frequently.
• Keep records of FOG pick-up by waste haulers onsite for at least of two years. Submit FOG reports to the City of North Liberty by email to [email protected].
• Store recyclable fryer oil in leak-proof containers with lids.
• Clean all vent hoods regularly.
• Do not introduce enzymes, emulsifying agents or bacteria to grease traps, grease interceptors or drain.

Frequently Asked Questions

What is FOG and why should I care?

FOG refers to fats, oil and grease that are generated from normal business operations of food service establishments (FSEs). Grease is commonly washed into the plumbing system during cleanup through the kitchen sink. As it cools, fats, oil and grease congeal and decrease pipe capacity both inside the FSE and in the main sewer system. FOG can block your drain, your neighbor’s drain and main collection lines, potentially becoming an environmental and public health risk.

Eliminating FOG-related sanitary sewer overflows is the goal of city FOG-related ordinances. Kitchens and FSEs must submit completed FOG Reports to ensure compliance with regulations. It is the responsibility of each business to develop an effective FOG waste management plan and properly dispose of FOG waste on a consistent basis.

What types of facilities are required to meet the directives of the ordinance?

All commercial and institutional cooking establishments as well as some non-cooking FSEs will be required to meet the regulations set forth in the ordinance. This includes, but is not limited to, restaurants, bars, schools, daycares, churches, nursing homes, bakeries, grocery stores, caterers and other food preparation operations.

Will my existing grease trap (indoor, under the sink unit) be sufficient to comply with the ordinance?

A grease trap that is properly sized and installed to remove the FOG at your FSE is important. Following the suggested best management practices and routine maintenance of the trap will increase the probability of meeting the discharge limits of the ordinance. Indoor grease traps are much smaller in design and therefore need more maintenance to prevent the FOG from reaching the sanitary sewers. Make sure baffles and deflector shields are installed properly. The North Liberty water pollution control plant also recommends dishwashers and garbage disposals bypass small, indoor grease traps as fats, oils and grease are emulsified by the soap’s detergents. If the trap is not cleaned frequently or correctly, it will not perform well and could put your FSE at risk of violating FOG discharge limits.

How often does my grease interceptor or grease trap need to be maintained?

A 25% rule applies to both grease interceptors and grease traps. This rule requires that the total of FOG, which float to the top, and solids, which settle to the bottom, should not exceed 25% of the grease interceptor or trap depth. Typically, cleaning frequencies for grease traps may be in the range of daily to weekly. Cleaning frequencies for grease interceptors can be expected to be monthly to quarterly.

This 25% rule allows the wastewater enough residence time inside the device to effectively remove the FOG and solids from the wastewater before it reaches the sanitary sewer collection system. The best way to reduce maintenance is scrape food debris in the garbage or compost and dry wipe dishes prior to washing them in the sink or dishwasher’s hot water.

May I use chemicals, enzymes or bacteria in my grease removal device or in my drains?

City ordinance prohibits the use of enzymes, emulsifying chemicals, hot water or other agents as a grease abatement method to grease removal devices or drains. These chemicals keep the FOG emulsified long enough to become a serious problem downstream as dilution of the chemical allows for the FOG to congeal and decrease pipe capacity, having the potential to cause a serious blockage and sanitary sewer overflow.

What are the most important things for me, the business owner or operator, to know about the FOG Program?

The North Liberty water pollution control plant may perform unscheduled compliance inspections. The important items our team checks for are:

1. The grease removal device (interior grease trap or exterior grease interceptor) is under 25% full of FOG and solids. This will be done via physical inspection by the NL WPCP Inspector.
2. Maintenance records, including accurate measurements (if required), are on-site and available at the request of the inspector. Records must be kept for a period of 2 years. Maintenance reports shall be submitted every 3 months or earlier to the City of North Liberty by emailing reports to [email protected].
3. Any additional requirements requested from the official inspection report.