Slippery when wet – avoiding grease management issues
You will always remember your first time. The stench, it’s unmistakeable. It’s truly unforgettable – an experience that certainly stays with you forever.
No matter how many times you are exposed, it’s like no other. If you’ve never had the opportunity of experiencing the results of an accumulation of fats, oils and grease (FOG), the main contents of a grease arrestor – especially one that has been incorrectly installed or maintained – then thank your lucky stars.
For me, my first encounter with a grease arrestor was as a young 18-year-old apprentice plumber. As the novice, I was tasked with resolving the issue, much to my journeyman’s amusement.
I’ll save you the graphic details of the extremely smelly and unbelievably sticky greasy waste I encountered, all while confined to a small courtyard at the rear of an upmarket restaurant. No matter how many times you wash your hands, shower and change your clothes, the smell lingers with you for weeks after.
Fast forward nearly 20 years – I was recently undertaking a due diligence survey in a large shopping mall, where a grease arrestor had been obviously neglected and poorly maintained for a significant length of time.
As the arrestor was located in a small room within a basement, where the mechanical ventilation system was not operational, this resulted in the stench being horrendous. The floor was so sticky it felt as though I was walking on strips of Velcro, having to physically lift each foot, shedding a layer off the sole of my boots with every step.
As with all hydraulic systems that are hidden from view, this particular grease arrestor room was clearly out of sight and out of mind, being so unhygienic that even the cockroaches had given up all hope of survival and were strewn in a large pile behind the door.
What’s the worst that could possibly happen? For many of us, designing, commissioning and maintaining a trade waste installation within any type of facility in a safe and compliant manner requires careful consideration, which cannot be overlooked, without major repercussions.
Because not fully appreciating the maintenance regimes for that far room in the basement of your facility – the one that nearly everyone mentions has a strange lingering odour, the zone where nobody dares to venture and there are always a few spare car park spaces – could have dire consequences.
Nearly all commercial facilities require some kind of trade waste drainage installation. In most circumstances, existing facilities containing trade waste installations undergo multiple refurbishments throughout the building’s design life.
The challenge facing the facility manager is to ensure each new food outlet tenant achieves and maintains compliance with the most appropriate pre-treatment, prior to conveying to the local authority sewer drainage system.
Being unaware of the level of design compliance required, as well as often trusting subcontractors undertaking tenant fitouts, can distract the building owner or facility manager from optimising the client experience and, at worst, can become catastrophic, complex issues.
Adapting and converting lettable spaces from retail units into new food outlets will have a direct impact on the volume of waste in the existing grease arrestor.
Not only does this have an impact on capital, life cycle and maintenance costs, it also has an effect on the available spatial requirements and this can have an impact on available car park spaces, which could have been otherwise rented out.
The facility manager can often be caught in the middle of corporate budgets, advice given from engineering design teams, subcontractors and the client, as well as existing tenants.
The plumbing system doesn’t always get considered and can be perilously overlooked, that is until a problem occurs, and when the problem involves a tenant with a large restaurant that can lead to a very big headache for the facility manager.
When designing a new building, the hydraulic consultant will be on hand to advise on the trade waste requirements. When retrofitting, however, the tenant fitout team can often be focused on the latest or costliest piece of equipment within the kitchen, instead of focusing on dealing with and treating the grease, which can inadvertently result in clogging the drainage system.
Some of the most common issues begin before the facility manager can have any influence at all, occurring early on at the design stage, often due to the wrong information being requested or provided.
With any refurbishment within an existing building, however, the facility manager is a key influencer in determining that the correct type of grease management system is installed, based upon their knowledge and experience of the facility.
The most common issues in existing buildings involve locating food outlets too far from the existing grease arrestor. This can be troublesome, due to the time taken for the grease waste to convey from the commercial kitchen area to the arrestor. This time lag means the grease contained within the wastewater will start cooling down and solidifying.
Over a short period of time this causes blockages within the network, resulting in disruption of the facility and the tenant not being able to operate, foul odours entering the building and trade waste violations – all of which ultimately result in loss of revenue damages to the corporate brand and reputation.
The location of the grease arrestor is paramount to ensure future servicing and maintenance for both emptying and cleaning periodically with little or minor disruption to the occupants.
Retrofitting within an existing facility can always be troublesome; however, every problem has a solution. This issue can be simply overcome by installing a new grease arrestor in close proximity to the source, with alternative methods including heat tracing/insulating pipework – each case is different.
It’s important to consider the equipment and fixture selection, as well as the location. For hygiene reasons, the wastewater discharge can be at a significant temperature as it goes down the drainage pipework, often in excess of 70 to 75 degrees Celsius, making the pipework material selection of critical importance.
The pipework is installed in straight lengths, but if the material has been incorrectly specified it will result in pipework that will sag due to being warped.
Not only does this cause future blockages, it can also be a hazard to the occupants on the level below, who are at risk of scalding, should the pipework give way and burst.
“The challenge facing the facility manager is to ensure each new food outlet tenant achieves and maintains compliance with the most appropriate pre-treatment, prior to conveying to the local authority sewer drainage system.
Another issue of high temperature discharge located in close proximity to the grease arrestor can be the grease effluent being flushed straight through the trap.
This is an example of poor design and one that we remedied recently at an independent survey on a busy building in Bondi, Sydney (with multiple restaurants and takeaway food outlets). The issue was overcome by reconfiguring the pipework arrangement.
Grease bypassing the trap will cause further issues down the line, in particular with the local water authority. A recent example of this occurred in the City of London in the UK, which is plagued with incorrect trade waste installations.
Congealed fat, oils, wet wipes and domestic waste that enters the drainage system often results in large deposits or ‘fatbergs’ floating within the sewer system.
In 2015, The Guardian newspaper reported that a 10-tonne fatberg had been removed from the ageing sewer system, taking over two months to remove and costing the Thames Water Authority in excess of $800,000, resulting in a clampdown on food outlets and fines being imposed.
Various local water authorities in Australia have launched marketing campaigns to raise awareness of disposing of FOG materials from within the sewer system.
So how can we avoid taking shortcuts? The majority of contractors and shopfitters are reliable and professional; however, a good design doesn’t always result in the best installation, or vice versa. The cheapest option is not always the right option to gain compliance. Always look to conduct a long-term workable solution, which will benefit the client and tenant alike, as well as keep servicing and maintenance contracts to a minimum.
No matter how large or small a fitout is, it is always recommended to engage an independent consultant to advise upon issues of compliance with standards and codes, providing piece of mind for both the new tenant and the building facility manager.
As with all systems, the key to a successful design is to consider the whole life cycle of the system installed and its usage, before preparing a regular and routine maintenance regime. In any trade waste installation, the key to avoiding blocked pipework is staff training.
Instigating control measures to avoid large particles entering the trade waste system is crucial. Avoiding cooking oil entering the system requires designated areas for storing and preventing spillage.
Generally, grease arrestors require cleaning every three months, although each case varies and depends totally upon the storage available and usage. In the majority of cases, the local water authority will require a trade waste agreement and the facility will be subject to spot checks.
It is the facility management’s responsibility, however, to ensure regular preventative maintenance is undertaken to avoid costly reactive repairs later.
The author, Paul Angus, is the Hydraulic and Fire Discipline Leader at Erbas & Associates. This article also appears in the April/May issue of Facility Management.