Fat, Oil, and Grease (FOG) Program Frequently Asked Questions

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 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, it congeals and decreases pipe capacity both inside the FSE and in the main sewer system. FOG can block your drain, your neighbors’ drain and main collection lines, potentially becoming an environmental and public health risk. Eliminating FOG-related sanitary sewer overflows is the goal of the City of Sioux City FOG program. FOG Inspectors will routinely inspect kitchens and FSEs 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 requirements of the FOG ordinance?

  • Any FSE that serves food 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 FOG 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 (BMPs) 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 City of Sioux City does not allow dishwashers to be tied to grease traps because the hot water (usually 140-180) will re-emulsify the FOG and bypass the trap, so a grease interceptor would be required. Garbage disposals can discharge into a grease trap, if the grease trap is only tied to that one garbage disposal. 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?

  • There is a 25% rule that applies to both grease interceptors and grease traps that states the FOG (floats to the top) and solids (settles to the bottom) content of the device should not be in excess of 25% of the grease interceptor / trap depth. (10in of solids at bottom +2in of FOG at the top/48in total depth = 0.25 = 25%)
  • Per the Ordinance, grease traps (20-55 gpm) are required to be pumped out weekly, or when the 25% rule is met, whichever comes first.
  • Grease interceptors (large, exterior, 500+ gallons) are required to be pumped quarterly, or when the 25% rule is met, whichever comes first.
  • 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 single 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-wiping and scraping dishes into the trash prior to dishes reaching the sink/dishwasher.

May I use chemicals, enzymes or bacteria in my grease control mechanism or in my drains?

  • The 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.
  • The City of Sioux City has only approved bleach in the right concentration for drain maintenance.

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

  • The City of Sioux City will be performing unscheduled compliance inspections. The important items the inspectors will be checking are:
    • The grease control mechanism (interior grease trap or exterior grease interceptor) is under 25% full of FOG and solids. This will be done via physical inspection by the Inspector.
    • That pump out records are on-site and easily accessible. Records must be kept for a period of 3 years.
    • That strainers are in the sinks to catch food scraps.
    • That the rendering container (the container for used fryer grease that you’re paid for) has its lids closed and shows no signs of a spill. If a spill occurs, please use kitty litter/quick dry to soak it up and then dispose of the soiled material.  

What are the enforcement action(s) that could potentially occur if the regulation of the FOG program are not met by my business?

  • Enforcement actions could include, but are not limited to (in no particular order):
    • Notice of violation without fine
    • Notice of violation with fines of $100-$1,000 per violation
    • Civil penalties
    • Submission of a compliance plan
    • Installation of a properly sized grease control mechanism (GCM)
    • Clean-up costs for sewer blockages
    • Termination of services

 Is there a FOG inspection fee? 

  • The City of Sioux City FOG Program does not have an inspection fee at this point in time.