‘The cardinal rule of cooking: your kitchen must be clean, and by clean I mean spotless!’ - Gordon Ramsay
In our previous blog post on kitchen hygiene, we looked at the risks associated with dirty kitchen equipment. In this post, we take a look at many a kitchen manager’s nemesis: the grease trap!
‘What on earth is a grease trap?’ I hear you thinking. Grease traps have been used since Victorian days, with Nathaniel Whiting from California obtaining the first patent for one the late 1800's. The design has remained largely the same since then, and utilise the same laws of physics: that grease and oil are lighter than water and will rise to the top when the mix is allowed to stand for a time.
A grease trap is therefore a plumbing device designed to slow down the flow of greasy wastewater and separate out the grease and solids before they enter the wastewater system. The water then flows down the pipe to the sewer, and the grease floats to the top and is retained in the trap.
Why are grease traps necessary?
Sewer and stormwater reticulation systems are under tremendous stress because they are being abused - often unknowingly - by residents who do not know where or how to safely dispose of their waste. The sewer reticulation system is only geared to accept toilet, sink, basin and bath waste, whilst the stormwater system is only geared to accept rainwater. Anything else - such as large volumes of grease - puts severe strain on the system and ultimately causes blockages.
Because restaurant and foodservice kitchens produce a large volume of waste grease which is present in the drain lines from various sinks, dishwashers and cooking equipment (such as combi ovens and commercial woks), all premises engaged in the cooking and preparation of food are therefore required by law to install and maintain an adequately sized grease trap.
So what happens to the fats, oils, grease and starch (FOGS) that are separated by the grease trap and prevented from entering the wastewater system, you may ask? These form a scummy layer in the grease trap that needs to be disposed of regularly. If not regularly cleaned out, the accumulation of FOG’s and foodstuffs can start to rot and give off the characteristic bad odour of hydrogen sulphide (rotten eggs).
It is the kitchen occupier’s responsibility to ensure the proper design and maintenance of their grease trap, and that it is proactively maintained in an effective working order. If the grease trap is not properly maintained, the occupier may be liable for any damages to the sewer system, have their industrial effluent permit withdrawn and/or have their entire industrial effluent discharge blocked off from the municipal sewer (as per Wastewater By-Law: Ch1 Section 3).
The risk of accumulated waste decomposing in waste pipes causing offensive odours, coupled with the fact that grease traps regularly become blocked and overflow, means that grease traps can pose a multitude of problems for kitchen managers. Mechanical cleaning methods such as high pressure water jetting or rodding are often unsuitable as they can cause damage to the drainage system, and may be the cause of bacterial contamination if not operated with care. Grease and sludge in the grease trap support bacteria and encourage pests such as cockroaches and flies.
Grease trap maintenance
Biological Dosing – offered as part of Initial’s CaterClean service or as a stand alone service - is an environmentally friendly, non-chemical maintenance program for grease traps. The biological enzyme, which is dispensed into the system in a metered dose, digests FOGS, thereby eliminating blockages. Installed, serviced and maintained by Initial, bio-dosing results in a free-flowing drainage system.
How does Biological Dosing work?
The Biological dosing unit pumps a measured dose of bio-enzymes into the grease trap. This initiates a biological process which digests and liquefies solid organic waste including oils, grease and fat. This keeps the organic waste free-flowing, and improves the quality of the effluent released into the municipal sewerage system. It also prevents pests and odour by reducing bacteria levels.
Improving the quality of the effluent is important because effluent water quality is governed by municipal bylaws**. Grease Traps must also comply with SANS 10 252-2, which means they must have solids separated out before FOGS separation. A correctly implemented Bio-dosing programme will cause these FOGS and foodstuffs to break down to water and carbon dioxide which comply to regulations and disappear from the system. The Bio-dosing treatment has no effect on non-FOGS and non-food type blockages such as plastic.
If you have a grease-trap that does not have a bio-dosing system that breaks down FOGS into water and carbon dioxide, then it needs to be skimmed regularly, and the solidified FOGS are to be collected regularly by a licenced waste oil collector. A copy of the waste transfer certificate must be kept for at least 2 years and be available for inspection, as per the Wastewater by-law.
Initial offers 2 types of bio-dosing unit: the type 1 pump is installed internally into waste water pipes, whilst the type 2 pumps are installed on outdoor grease traps which are usually located at the back receiving area of restaurants, where waste water exits the kitchen. Units are serviced regularly and after-hours services are available for busy restaurants.
When aiming for a spotless kitchen of which even Gordon Ramsay would approve, it’s critical not to overlook the risks (both hygiene and legal) that may be caused by not adequately maintaining your grease trap.
*Legislative Requirements for the Maintenance of Grease traps:
The General Hygiene Requirements for Food Premises and the Transport of Food (R.918/1999) corrected by Govt notice No 638 of 22 June 2018 specify that food premises must have a wastewater disposal system approved of by the local authority, and that the duties of a person in charge of food premises include ensuring that wastewater on the food premise is disposed of to the satisfaction of the local authority.
**Western Cape Provincial Wastewater By-Law: 1 Sep 2006. Section 3: Protection of Municipal Sewers
No person shall discharge, permit to enter or put into any municipal sewer -
- Any petrol, oil, greases, waxes, fat or pesticides, insecticides or paints
- Any liquid that has a pH value of less than 5,5 or greater than 12
For more help of getting your restaurant hygienic and safe, contact us and one of our specialist will assist you.