There are around 200,000 sewer blockages in the UK every year and, according to industry body Water UK, up to 75% of these are caused by fats, oils and grease.
FOG sticks to the inside of pipes and tunnels, solidifying and accumulating until it restricts the flow of waste water, or even blocks the sewers. FOG disposed into sewers from the UK’s 260,000 foodservice outlets accounts for a significant proportion of this, with the extent of the issue particularly apparent in places where there is a high density of such businesses.
“The FOG problem is also being exacerbated by a number of factors,” insists Martin Fairley at ACO Technologies, a business which has been supplying leading drainage systems for more than 60 years.
“These include climate change, with increased rainfall leading to greater surface water run-off into a combined sewer system, as well as changes in eating habits which mean that people are eating out and consuming fast food more frequently. When you consider that the estimated cost of managing FOG in the Thames region alone is thought to be £12m per year, it’s clear that urgent action is required to tackle the issue.”
Under the Water Industry Act (1991) s.111, discharge of any material prejudicial to sewer function is illegal. However, points out Fairley, it is extremely challenging for water authorities to manage the issue via legislation, particularly as high concentrations of foodservice outlets in one area make it difficult to pinpoint the source of the problem.
“As a result, prosecutions under S.111 are few, with only one case identified where an operation was successfully prosecuted for FOG discharge by Seven Trent Water in 2009,” he says.
Building Regulations (2000) s.2.21 Part H does go some way to addressing the issue, stating: ‘Drainage serving kitchens in commercial hot food premises should be fitted with a grease separator complying with BS EN 1825-1:2004 (design) and designed in accordance with BS EN 1825-2:2002 (selection, operation and maintenance) or other effective means of grease removal’.
However, although new buildings or those undergoing a change of use fall within the remit of Building Regulations, existing buildings and many refurbishments do not.
“Even the smallest grease separator requires substantial space to house and maintain, with many designed to be located in a basement or below ground externally,” says Fairley. “Many smaller businesses — typically those supplying 100 meals or less per day — may not have the space for such equipment.
There is also the issue of large-scale kitchens, where long drain runs and multiple FOG sources at different locations within the building require interception.
In both cases, establishments will often employ alternative methods of FOG management, including smaller separators that are not designed to the Standard, separators incorporating bacteria-based dosing — effectively creating ‘bio-degradation’ vessels — and mechanical skimming devices.
“However, none of these technologies are currently covered by a recognised British Standard — performance and operating conditions must therefore be obtained from the manufacturer concerned. Such a situation is hardly ideal, and should be a cause for concern for users and specifiers alike.”
The current best practice guidance documents relating to this issue largely focus on the removal of FOG before dishwashing and subsequent disposal of FOG-laden waste water into the sewerage system.
However, outside of BS EN 1825, little attention has been focused on the testing, selection, installation and maintenance of products designed to manage FOG. Even knowledge of collected FOG disposal options across the industry is poor, insists Fairley.
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“What is clear is that much more can be done to understand the performance of the various systems now available. Such investigation would hopefully lead to the revision of existing legal and regulatory mechanisms, as well as robust product standards and guidelines, all of which is vital if we are to make any headway when it comes to successfully tackling the problems caused by FOG.
“In the meantime, the existing Standard provides ample, independent, guidance — its complexity can be easily circumvented through liaison with a suitably qualified supplier. Notably, as the Standard is harmonised across the European community, from July 1st 2013 all products must now carry the CE mark as required by the Construction Products Regulation. This alone should ease the process of selection and the ‘CE’ mark question should be the first asked in any prospective procurement.”
Fairley argues that better education and collaboration is also needed throughout all tiers of the supply and waste water chain, from manufacturers and foodservice and catering equipment representatives through to designers, consultants, business owners and water firms.
This must take into account all aspects of the process, including design, construction and operation, to ensure solutions implemented at any point of the chain are fit for purpose and do not impact negatively elsewhere.
“When it comes to establishments with commercial kitchens there are often separate engineers for general and kitchen drainage, so communication between these specialisms is key in order to ensure successful FOG management and minimise any impact in the building drainage and sewers.
Additionally, there are a number of factors that kitchen drainage specialists must take into account when specifying products, including the kitchen lay-out and location of potential FOG sources, operational requirements and maintenance preferences.
“Most importantly, attention must be paid to hygienic factors which are particularly important when considering maintenance,” adds Fairley.
With a quarter of a million foodservice establishments operating in the UK, raising awareness of the issues relating to FOG among the workers in these businesses is imperative. Ongoing training to promote best practice and drive change in kitchens is vital.
“There is a complex web of issues contributing to the build-up of FOG, ranging from economic, environmental and behavioural factors to legislative drivers, so any solution must encompass all of these aspects in order to minimise costs for the operator and prevent this ‘out of sight, out of mind’ problem from spiralling out of control,” concludes Fairley.