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Protecting Your Drains From FOG - Fats, Oil, Grease


Protecting Your Drains From FOG - Fats, Oil, Grease

FOG (fats, oil and grease) are a real threat to your drain lines and grease trap if not managed properly. While you can control debris from getting into your drains you can’t stop FOG. FOG is a slow moving buildup of sludge in the drain lines clogging your plumbing systems while reducing the needed flow. The best practice to remove FOG requires the needed service of a plumber to clear the system in a way that keeps the restaurant running without disruption and damage to your drain lines

The following is a brief tutorial and guide to help manage your drainage systems:


•      Cast iron is the most commonly used and is a magnet for FOG clinging to it. Cast iron is my least favorite as it relates to FOG. It needs to be serviced more frequently and takes more vigor and time by a plumber to properly service the drainage system by a plumber. 

•       ABS or PVC are better in repelling FOG from sticking to it and is much easier for a plumber to service. The down side with ABS/PVC is that it can break easy if a plumber uses a cable to clear a clogs rather than a hydro-jetter 

•      Stainless steel drainage systems are the best of both ABS/PVC and cast iron and fall in the middle as to FOG sticking to it.    

Grease Trap and Interceptors:
Grease traps and interceptors are one in the same and are often used interchangeably when speaking with vendors and those servicing them. Technically, however, interceptors are in ground traps usually 1000 gallons or greater while grease traps are smaller units staged directly under a dish machine when in-ground traps are not able to be installed.  When grease traps/interceptors are installed it is important to implement a proper program to combat the effects of FOG. If the FOG level in a grease trap/interceptors is allowed to thicken or sit too long, FOG can cause the baffles and internal plumbing lines to clog-up leading to over flowing traps or major clogs in a city line or worse. Check with your grease hauler on the proper frequency of service.  The following might be the starting point for your consideration for pumping the grease trap/interceptors.
1,000 to 2,500 gallon trap             Pump Monthly
2,500 to 3,500 gallon trap             Pump Every 3 Months
3,000 to 5,000 gallon trap             Pump Quarterly  
5,000 to 10,000 gallon trap           Pump 3 to 4 times a year

Traps that are 8,000 to 10,000 gallons are not pumped as frequently due to the volume it can hold; however, caution must be taken as less frequent servicing can lead to food and sediment build-up causing high levels of hydrogen sulfate (odors), build up on the traps baffles, clogging of internal drain lines or more than normal debris blocking the outlet lines. 

Enzymes to control FOG levels is somewhat successful but very costly. In most cases an enzyme program can be 3 to 4 times more than hydro jetting.  Keep in mind Enzymes are living organisms and when chemicals, such a degreasers, are used to clean a restaurant the enzymes are killed defeating the purpose of their use.  When considering the yearly cost for the application of Enzymes, hydro jetting your drain lines is more effective

Recommendation to Control FOG:
First, determine and have the grease trap serviced at the proper frequency with the right vendor making sure the trap is thoroughly pumped with the baffles and walls scrapped or pressured washed. Second, set up a service where the drain lines are hydro jetted with 4000 psi once a year. High volume restaurants, if necessary, can be serviced twice a year.  Since it takes time for FOG to build up in a drain line, performing the service monthly is unnecessary. Remember too, when hydro jetting your lines, to also jet the exit line of the grease trap to the city or common shared line, whichever is first.