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Q: What is FOG?

A: FOG refers to fats, oil, 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 one of the County's water reclamation facilities (WRF).

Wastewater comes from everyday activities we all do, such as washing dishes, taking a shower, running the washing machine, and of course, flushing the toilet. Anything that goes down a drain enters the collection system. Click here to learn more and see the system in action.

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Q: How exactly does FOG clog up a pipe?
Watch this closed circuit TV (CCTV) footage of an actual sewer line inspection in Gwinnett County. FOG has significantly narrowed the opening in the pipe making it difficult for the flow and even the CCTV line to move through it.

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 – gets tangled up in all 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?

*Based on 2007 population estimate of 776,347 as determined by the Gwinnett County Forecasting and Research Division.

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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 Gwinnett's collection system, then you have a vested interest in the reliability and life span of the system and treatment plants. Even if you never experience a FOG-related overflow, the rates you pay on your monthly Gwinnett County Department of Water Resources bill fund the maintenance, repair, and replacement of the system.

Plus if there is a spill that gets into a waterway, the County could be fined and have to pay other clean up costs as well. There is also the potential for ecological damage to the 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 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. 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 culprits 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 Gwinnett have a serious FOG problem?

A: Fortunately, the County has a strong spill prevention program and one of the lowest records of incidences in the metro area. While FOG does not cause every overflow, it contributes to the majority of them.

And it is impossible to entirely eliminate FOG from the system. Even with the low number of backups, the aftermath of FOG-related overflows can be expensive.

In 2008, the County spent more than half a million dollars on clean-up and property restoration caused by FOG-related overflows.

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Q: What if I have a sewer back up on my property? Will the County 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, then it is the County's responsibility to handle clean up and repair. 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 Water Resources' field crews service County sewer lines removing FOG before if causes problems. They cover approximately 600 miles of pipeline a year, which is the equivalent of driving from Lawrenceville to Washington, DC.

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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 in an unincorporated city in the County. Do I need to be concerned about FOG?

A: Yes. FOG is a problem in communities across the country and around the world, essentially in any place that has a sewer collection system.

Also, even though you don't live in an unincorporated part of the County, DWR's collection system serves most of the County with the exception of Buford, Braselton and parts of Norcross and Loganville.  See the service map for details.

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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 County's FOG ordinance which lays out the steps they have to follow to keep as much FOG as possible out of the collection system.

This includes having onsite grease traps that must be cleaned and inspected on a regular basis; they are also required to keep records on hand showing their maintenance practices. The County employs three full-time inspectors who ensure that FSEs in the county are in compliance with the FOG ordinance. In 2008, they completed 3,015 compliance inspections – an average of more than 11 a day!
A well-maintained grease trap (left) vs. a poorly maintained one (right). The one on the left if is in better shape because it has the appropriate liquid level in the trap and the water in the trap is somewhat clear.

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Q: What happens to the grease from restaurants and FSEs?
A: Grease haulers licensed by the state pump the grease from traps and dispose of it properly.  Some types of oil and greases can be recycled and used in a variety of everyday products such as pet food, cosmetics, skin care products, soap, and more.

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.

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 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

Use water to "pre-wash" plates  

Scrape plates over the trash can or dry wipe with a  paper towel


Pour used oil down the drain

  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 hot grease (including poultry skimming) down the drain


Pour cooled grease  into a grease can or other container for disposal and/or absorb with paper towels or newspaper

Pour grease down the storm drain.   Pour cooled grease into a container, seal it and place it in the trash.

Mesh drain screens, paper towels and original oil containers are good tools for fighting FOG


Other ways to be a part of the FOG solution include reporting any illegal dumping or spills immediately. You can also help by educating your neighbors and others in your community; you can even schedule a speaker from DWR for your community group. 

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Download our brochures to learn how you can help "Unclog the  FOG"