Frequently Asked Questions
About Watling Hope
About FOG
The need for Fat, Oil and Grease Management
Do I need a grease trap or grease treatment system?
'But we don't cook Fatty-Food?'
What is the legislation surrounding grease traps and grease management?
What methods are there for tackling FOG?
Trap It - Grease Separation
Common grease trap systems
How grease separation works
Maintenance of Grease Separators
Treat It - Grease Treatment
How grease treatment works
How biological treatment works
Maintenance of Grease Treatment Systems
Sources
About Watling Hope
Who we are
Established in 1993 Watling Hope are a specialist drainage company primarily serving the UK food service sector. We work with some of the UK's leading food service operators through to independent pubs, cafes and restaurants providing advice, support and equipment to keep drains running, premises compliant and costs at a minimum. We are ISO9001 accredited, Safe Contractor Approved and a member of British Water the trade body for the UK Water Industry.
We're here to help
Watling Hope FOG offers a wide-range of products for the management of fat, oil and grease. All of which you can purchase 'off the shelf' for delivery to site. We also offer a bespoke FOG management service where we will survey your site and design a scheme best suited o your business. Site surveys are offered nationwide at no cost.
Finding the right solution for you
At Watling Hope we are here to help you make the right choice for your business or project - from initial cost through to ongoing maintenance. Please call our FOG Team on 01789 741825 to discuss your requirements.
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FOG Explained
About FOG
Fat, oil and grease enters the drainage systems of commercial premises from washing of pots, pans, plates and utensils. In warm water FOG is in suspension and can be easily washed into the drain-line, however once the effluent cools the FOG comes out of suspension and forms a sticky coating on the walls of the pipe-work.
Left untreated this fatty-coating will build-up and in so doing will reduce the throughput of the pipe. Once the bore has been significantly reduced it is a matter of time before the there is a complete and catastrophic blockage.
The need for Fat, Oil and Grease Management
With up to 70% of drain blockages in commercial kitchens caused by a build-up of Fat, Oil and Grease (FOG) the need for effective grease management is vital for any commercial catering operation. Watling Hope work with some of the UK's leading pubs, restaurants, hotels and commercial caterers. We assess each kitchen on a site by site basis and provide systems to reduce the risk of drain blockages, improve hygiene and minimise the environmental impact of the kitchen on the connecting drainage and environment.
Do I need a grease trap or grease treatment system?
If you produce food and as a result wash-up pots, pans and utensils onsite you will be producing FOG. Even a B&B producing 10 meals per day will be generating significant build-up of fat, oil and grease in the drainage system which will in time lead to bad odours and ultimately a blockage.
'But we don't cook Fatty-Food?'
A common misconception is that fat, oil and grease is only a problem for kitchens where food is grilled or friend. On the contrary - fat and oil in kitchen drainage is derived from oils, meat, fish and dairy preparation and increasingly the use of combination steaming ovens.
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What is the legislation surrounding grease traps and grease management?
For existing premises the reasons for fitting a FOG management system tend to be as a result of drain problems, pressure from the local authority, landlord or environmental health. It is however a requirement under the Water Industry Act 1991 to ensure that your premises does not discharge any product into the drain which may interfere with its operation.
Taken from the Water Industry Act 1991
Provisions protecting sewerage system
111 Restrictions on use of public sewers
(1) Subject to the provisions of Chapter III of this Part, no person shall throw, empty or turn, or suffer or permit to be thrown or emptied or to pass, into any public sewer, or into any drain or sewer communicating with a public sewer-
(a) any matter likely to injure the sewer or drain, to interfere with the free flow of its contents or to affect prejudicially the treatment and disposal of its contents
Thames Water reported that in 2007/2008 over 60,500 sewer blockages reported were caused in part by FOG.
With the cost running into Millions of Pounds Water Authorities are more and more adopting a 'polluter pays' principle where they will trace the problem back to the offender. The Thames Water website states "During 2007/08, we saw the continued success of the fat, oil and grease pollution prevention programme of targeting blockage hotspots, with a further 1,501 visits undertaken at food service establishments across our catchment."
For new-builds fitting a grease trap or grease removal system is a statutory requirement in the UK under Part H of the British building Regulations. Part H states under item 2.21 -
"Drainage serving kitchens in commercial hot food premises should be fitted with a grease separator complying with prEN 1825-1and designed in accordance with prEN 1825-2 or other effective means of grease removal."
PrEN 1825-1 (now BSEN 1825) is the European standard for gravity grease interceptors. The standard provides guidance purely for separators sizes where FOG is to be removed by gravity alone. Gravity separators are very large and not often practical for retro-fit. The British Building Regulations therefore takes a practical view and allows the use of "other effective means of grease removal" which can refer to biological dosing equipment or automatic grease separators.
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What methods are there for tackling FOG?
Although there are many derivatives of each there are in essence two methods of controlling fat, oil and grease build-up. It can either be trapped using a grease separator or treated using biological or chemical dosing.
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Trap It - Grease Separation
Common grease trap systems
" External in-ground grease interceptors / grease traps (inc BSEN1825)
" Internal at source grease traps
" Internal at source enzyme dosing grease traps
" Internal automatic grease separators
" Centralised automatic grease traps
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How grease separation works
Fat, oil and grease has a lower specific gravity than water and as a consequence it floats on it's surface. This principle makes a conventional grease trap extremely simple and very effective.
Typically a grease trap or grease separator is a tank or chamber with an integral baffle-wall. The wall runs from the top of the tank to just short of it's base - effectively dividing the chamber into two compartments.
The system works as follows
1. kitchen effluent passes into the chamber which slows the flow and allows the oil content to separate from the water.
2. Once separated the oil content floats to the surface creating a layer of fat, oil and grease.
3. 'Cleaned' water is allowed to pass under the baffle wall and onto the main drainage system.
This separation principle is employed in grease-traps ranging from indoor under-counter units to large below-ground systems and automatic grease separators.
Watling Hope supply grease traps for all applications from 20 litre stainless steel under sink units to 8000 litre underground separators.
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Maintenance of Grease Separators
Once installed the grease trap or grease separator will require regular emptying using a vacuum unit. Emptying can be carried out by Watling Hope who are a licensed waste carrier. In order to keep the drain-line clear between the grease-trap and the kitchen and to prolong the time between emptying biological grease digestion products can be used. Systems such as the Grease Guzzler and Grease Goblin DTS will seed the trap with colonies of fat-degrading bacteria which break down FOG and control odour - in some cases dosing may reduce the emptying frequency of the trap to Zero.
Treat It - Grease Treatment
Common Systems
" Enzyme dosing systems
" Enzyme and bacterial dosing systems
" Activated biological dosing systems
" Sewage Sump dosing equipment
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How grease treatment works
Traditionally the only option for managing grease was to use a grease trap. However advances in biotechnology have led to the identification of naturally occurring micro-organisms which have an ability to actually break down fat, oil and grease particles.
Watling Hope have been at the forefront of biological grease digestion since we pioneered the technology with a major UK restaurant group in 1997.
Biological systems (sometimes knon as bioremediation systems) work by colonising the drainage system with grease digesting bacteria. Once established the bacteria work to digest the fat as and when it cools on the walls of the pipe, thus leaving the drainline clear and free-running.
There are a number of systems available from simple drip-fed wall-mounted enzyme systems to pumped dosing systems through to pre-activated dosing systems.
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How biological treatment works
Grease is essentially a mixture of long-chain fatty acids and glycerol.
C-g-C-l-C-y-C-c-C-e-C-r-C-o-C-l-C
Biological treatment works by first using enzymes to strip down the bond between the glycerol and the fatty acids.
C g C l C y C c C e C r C o C l C
This reduces the matter into smaller more digestible particles.
C C C C C C C C C
g l y c e r o l
The specially selected bacteria then latch onto and degrade the grease deposits reducing them to their core components - water and carbon dioxide.
C C C C C C C C C
g l y c e r o l => H20 & C02
Watling Hope supply a range of biological grease treatment products which incorporate high performance cultures of micro-organisms for use in a variety of applications. All products have been extensively tested in the field for top levels of performance and environmental impact.
Contained in liquid or powder form these products can be used to treat grease either in an existing grease-trap which will reduce the trap emptying frequency or as a stand-alone drain maintenance product.
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Maintenance of Grease Treatment Systems
Grease treatment systems are reliant on refilling with biofluid or biopowder to operate. This can be expensive but it is often not as expensive as it is to clean out a grease trap - and much less disruptive.
Additional FOG products
" Internal at source food filters traps
" Internal at source coffee sediment filter traps
" In-sink strainers with sink adaptor
Additional FOG services
" Grease trap emptying
" Grease trap servicing
" Grease trap cleaning
" Grease trap user training
" Grease trap installation
" Biological dosing system installation
" Biological dosing system servicing
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Sources
Water Industry Act 1991 http://www.opsi.gov.uk/
British Building Regulations http://www.opsi.gov.uk/
Thames Water Website http://www.thameswater.co.uk/cps/rde/xchg/corp/hs.xsl/6877.htm
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Water UK Guidance on Grease Traps 
