Large amounts of fats, oils and grease in the wastewater cause trouble in
the collection system pipes. It decreases pipe capacity and, therefore,
requires that piping systems be cleaned more often and/or some piping to
be replaced sooner than otherwise expected. Oil and grease also hamper
effective treatment at the wastewater treatment plant. Grease in a warm
liquid may not appear harmful. But, as the liquid cools, the grease or
fat congeals and causes nauseous mats on the surface of settling tanks,
digesters, and the interior of pipes and other surfaces which may cause
a shutdown of wastewater treatment units.
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An interceptor is a small reservoir built into the wastewater piping
at least 15 feet from the grease producing area. Baffles in the reservoir
retain the wastewater long enough for the grease to congeal and rise to the
surface. The grease can then be removed and disposed properly.
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An interceptor is a vault with a minimum capacity of 1000 gallons that is
located on the exterior of the building. The vault contains baffles. It
includes a minimum of two compartments, and flow between each compartment
is designed for grease retention. The capacity of the interceptor provides
adequate residence time so that the wastewater has time to cool, allowing
any remaining grease not collected by the interceptors time to congeal and
rise to the surface where it accumulates until the interceptor is
cleaned. To view a FOG interceptor, click here
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All FOG interceptors should be cleaned at least four times each year. Some
establishments will find it necessary to clean their interceptors more
often. If the establishment has to clean it too often, the owner may be
required to install a larger interceptor.
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If the establishment is uncertain whether it has an inside FOG interceptor,
or outside FOG interceptor, the owner should contact the DeKalb County
Department of Watershed Management FOG program at (770) 621-7272 for
assistance.
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Any establishment that introduces fats, oils, or grease into the drainage
and sewage system in quantities large enough to cause line blockages or
hinder sewage treatment is required to install a FOG interceptor. Interceptors
are required for high volume restaurants and large commercial establishments
such as hotels, hospitals, factories, or school kitchens. FOG interceptors
are required for small volume (fast food or take-out restaurants with limited
menus, minimum dishwashing, and/or minimal seating capacity). Medium volume
establishments may be required to install an interceptor depending upon the
size of the establishment. To view a FOG interceptor,
click here
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Please contact the DeKalb County Department of Watershed Management FOG Program
at (770) 621-7272 for proper sizing. Proper sizing will depend on many things,
and is unique in nearly every establishment. The size will also depend largely
upon the maintenance schedule. If a FOG interceptor is not maintained regularly
it will not provide the necessary grease removal.
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If the establishment uses fats, oils, or grease in food preparation, it
will eventually encounter a maintenance problem with a plugged building
sewer line. The blockage can create a sewer backup situation and ultimately
a potential health problem in the establishment. Someone will have to pay
for removing the blockage. If the problem is in the building sewer line,
then the establishment has direct responsibility for paying for the
maintenance. If the blockage or restriction is in the public sewer main,
and it can be proven that the establishment is the cause of the blockage,
then the establishment may have to pay for the public sewer to be
maintained. Blocking a sanitary sewer line is also a violation of the
federal Clean Water Act.
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Contact the Compliance Inspector for your area. Click here
to determine which Compliance Inspector is available for your area. When
the Administrative Authority requires waste pretreatment, an approved FOG
interceptor shall be installed. The rules of DeKalb County will assist
the establishment in determining if a FOG interceptor is required.
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The establishment should contact the DeKalb County Department of Watershed
Management FOG program at (770) 621-7272. This will enable DeKalb County
to assist the establishment in the proper sizing of their FOG interceptor,
cleaning schedules and advise them on kitchen practices.
See the DeKalb County Map for the Compliance
Inspector for your area.
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