Frequently Asked Questions

Q: What is FOG?

A: FOG refers to fats, oils and grease, which are the natural by-products of food preparation and cooking or baking.

While they may add extra flavor to your food, if they are poured down the drain, they can leave a real mess in the sewer collection system by forming clogs and blockages that lead to overflows.

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Q: What is a collection system?

A: The collection system is a network of pipes and pump stations that moves wastewater from homes and businesses to the City’s wastewater treatment plant (WWTP).

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Q: How exactly does FOG clog up a pipe?

A: FOG seems harmless when it is a warm liquid because it goes down the drain so easily. But once it cools off, it sticks to sewer pipes and builds up over time.

Plus whatever you put down the drain or garbage disposal, such as coffee grounds or eggshells, or toss in the toilet (besides toilet paper) – hair, dental floss, cigarette butts, candy wrappers, toys, kitty litter, ANYTHING – get tangled up in that FOG.

This blocks the flow of wastewater through the pipe forcing it back up the drain resulting in flooding of a home, a street, or a stream with wastewater.

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Q: Does it really make a difference if I pour just a little grease down the drain?

A: Yes! If every person in Lawrence poured just one teaspoon of FOG down the drain, it would be the equivalent of dumping over two 55-gallon drums of FOG into the sewer*. Every little bit adds up to create big clogs that cause spills and overflows. In fact, in the past three years, 90% of FOG-related overflows happened on residential lines.

*Based on estimated population of 90,000.

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Q: Doesn’t using soap or the garbage disposal take care of FOG?

A: FOG does not mix with water, and detergents used to “wash it down the drain” typically separate from the FOG after a period of time, which means that it ends up clinging to the pipes, restricting the flow of wastewater.

The garbage disposal just chops up the bits of food you put into it, basically moving the problem downstream. The bottom line is that using soap or the disposal is not the solution to reducing FOG.

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Q: But if I don’t have an overflow, does FOG really affect me?

A: Yes! If you are connected to Lawrence’s collection system, then you have a vested interest in the realiability and life span of the system and treatment plant. Even if you never experience a FOG-related overflow, the rates you pay on your monthly Utility bill fund the maintenance, repair, and replacement of the system.

Plus if there is a spill that gets into a waterway, the City could be fined and have to pay other clean up costs as well. There is also the potential for ecological damage to the City and County’s waterways that contribute to the quality of life for all residents.

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Q: What should I do with leftover oil or grease?

A: You can pour small amounts of used oil back into its original container (or another container with a top) once it has cooled and then put it in the trash can.  The City of Lawrence Household Hazardous Waste Facility accepts cooking oil for recycling. Pour liquid grease into a grease can or another container. Once it has cooled and solidified, you can throw the container away.

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Q: How do I know what foods are a source of FOG?

A: Some common cuprits are food scraps, meat trimmings, poultry skin, the “skim” from soups and gravies, cooking oils, lard and shortening, salad dressings, sauces and marinades, dairy products (including ice cream), and butter and margarine.

And if you use your garbage disposal to dump coffee grounds, eggshells, or other items down the drain this will accelerate FOG related clogs since it provides extra surfaces for everything to stick to.

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Q: Does Lawrence have a serious FOG problem?

A: Although, the City has a strong line cleaning and maintenance program and a very low record of incidence,  we still have basement back-ups due to grease. These back-ups are expensive for the homeowner. And the cost of clearing the lines of grease to prevent the back-ups is significant.

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Q: What if I have a sewer back up on my property? Will the City take care of it?

A: It depends on exactly where it is located on your property. If the backup occurs in your sewer lateral (the pipe that connects the drains from homes and businesses on private property to the collection system) then clean up and repair is your responsibility.

If it is in the main line (the part that the City owns and maintains), then it is the City’s responsibility to handle the clean up on the City right-of-way and repairs.

This is why it is important for property owners to maintain their sewer laterals, having them cleaned out on a regular basis to prevent FOG buildup or root intrusion.

Department of Utilities field crews service City sewer lines removing FOG before it causes problems. They clean over 100 miles of pipeline each year, which is the equivalent of driving from Lawrence to Junction City.

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Q: My neighbor had a sewer back up because of tree roots. Is this a problem too?

A: Yes. Tree roots seek out water as they spread through the ground and can easily crack a pipe in their search, especially if it is an older clay pipe. Tree roots typically “attack” at the joints first.

The combination of tree roots and FOG can very quickly produce a clog in a sewer lateral. The best way to avoid this is to plant any trees several feet away from your sewer lateral.

You can locate the lateral by finding the clean-out pipe in your yard, usually toward the street or sidewalk.

For residents with older, established trees, it’s a good idea to perform regular maintenance on your sewer lateral so that roots don’t have a chance to take hold.

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Q: I live outside the Lawrence city limits or am not connected to the City’s collection system. Do I need to be concerned about FOG?

A: Yes. FOG is a concern to you, because it may cause clogging of the lateral that goes to your septic tank or other on-site treatment system. Avoiding disposal of FOG down your drain is a good practice regardless of the system you are on.

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Q: What about restaurants? They generate more grease than residents do.

A: It is true that restaurants and food service establishments (FSEs) typically generate more grease than residents. However, they must comply with the sewer use ordinance which addresses the use of the City’s collection system. Restaurants and FSEs should have on-site grease traps or interceptors  that must be cleaned on a regular basis.  To learn more about restaurants and grease click here.

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Q: What happens to the grease from restaurants and FSEs?

A: Grease haulers pump the grease from traps and dispose of it properly. Some types of oil and grease can be recycled and used in a variety of everyday products such as pet food, cosmetics, skin care products, soap, and more.

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Q: What can I do to help clear up FOG?

A: Being a part of the solution is as easy as following some standard practices around the kitchen, such as:


  • Wash food scraps (solid or liquid) down the drain, dump them in the toilet, or grind them up in the garbage disposal.
  • Wash contents of soaking pots and pans down the drain.
  • Use water to “pre-wash” plates.
  • Pour used oil down the drain.
  • Pour hot grease (including poultry skimming) down the drain.
  • Pour grease down the storm drain.


  • Use mesh drain strainers to catch solid food scraps for disposal in a trash can.
  • Pour liquid food scraps, e.g. sauces, milkshakes, into a container and place in the trash can.
  • Scrape plates over the trash can or dry wipe with a paper towel.
  • Pour used oil into a container with a top (the original if available) so it can be reused, recycled, or placed in the trash can for disposal.
  • Pour cooled grease into a grease can or other container for disposal and/or absorb with paper towels or newpaper.
  • Pour cooled grease into a container, seal it and place it in the trash.

Other ways to be a part of the FOG solution including reporting any illegal dumping or spills immediately. You can also help by educating your neighbors and others in your community.

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