YYZ’s grease problem: How GTAA maintenance teams solved it

By Steve Gahbauer   

Facilities Maintenance Industry Manufacturing grease manufacturing

Infrastructure reliability focused on better serving passengers and tenants.

Terminal 3, Lester B. Pearson International Airport. PHOTO: BUFFYJOSSDOLLHOUSE

Rapid growth of Toronto’s Pearson International Airport (YYZ) put strain on mechanical systems, but the maintenance teams found ways to meet the challenge. How they did so offers some useful facilities maintenance take-aways for manufacturers.

The number of travellers passing through Toronto’s Lester B. Pearson International Airport has risen steadily from 41 million in 2015 to 47 million last year. As a result of this kind of growth, new retail food establishments were added. In turn, this and other growth developments created challenges for maintenance teams of the Greater Toronto Airports Authority (GTAA).

In a detailed presentation at a MainTrain maintenance conference convened by the Plant Engineering and Maintenance Association of Canada, Clarence Walters, the GTAA’s manager of mechanical systems, shared his experience with the airport’s projects.

Walters is responsible for the maintenance and repairs of the Life Safety and the plumbing systems.


The rapid growth of traveller traffic has put a heavy strain on the airport’s plumbing infrastructure, with the number of failures climbing steadily. This had an impact on passengers, customer operations and retail tenants. The maintenance team’s main focus had to be reducing the number of failures and improving the reliability of the infrastructure.

One of the issues was cast iron pipes designed to last between 25 to 30 years failing in less than 15 years. The teams used a simple “five why” template and carried out a root cause analysis, which revealed the major problem was grease.

Build-up in the lines not only blocked the drainage pipes but added excess weight to the entire system. Solidifying grease is corrosive and quickly deteriorates cast iron pipes and decaying grease attracts vermin. Although not an immediate threat due to the airport’s stringent cleaning standards, it was an issue that needed better control.

When blockages occurred, the normal response was to snake the lines, but the problem would recur. On one occasion, while snaking the drains, the joint let go and a six-foot section of pipe fell through the ceiling into an unoccupied area. This prompted the maintenance teams to take a serious look at the infrastructure, the causes of failures and to develop a comprehensive plan to deal with the problems.

The first priority was the corroding pipe. Proper maintenance was difficult because cleanouts (installed as per building code) were suspended in the ceiling spaces above restaurants, retail locations, passenger screening areas, and often baggage belts. Maintenance stipulated cleanouts must terminate in the tenant floor space so lines are easily accessible for cleaning.

Piping priorities

The teams also looked at the cast iron pipes, which were not standing up to daily use. Breakdown maintenance was the only type being done because of the few hours available when restaurants were closed, and the inaccessibility of the cleanouts.

Other types of piping were researched, which led to a piping product called XFR, made by IPEX and used by other airports. XFR meets fire code requirements, has a low coefficient of friction and is 75% lighter than cast iron, making it a lot easier to work with. And training was provided by an IPEX representative.

All new restaurants were required to adhere to new standards for drainage piping, the first being the location of the cleanouts and the second the type of material used for the drains. However, the root cause of the problem was grease draining into the pipelines. So the maintenance teams looked at the restaurants and their practices.

All restaurants were equipped with passive grease interceptors relying on the principle that oil floats to the surface and hardens when it cools, which can then be pumped out. However, only the water from the preparation sinks was being plumbed into the grease interceptors. The frequency of cleaning was not adequate because, as the units filled, much of the fats and oils would flow down the drain. With the type and volume of food preparation, kitchens required frequent pump-outs, although they were not being done frequently enough.

Another major issue was water from commercial dishwashers bypassing the grease interceptors and emptying directly into the drains. Checking the plumbing code revealed it wasn’t mandatory to plumb the dishwasher water into the grease interceptors. A dishwasher with a water booster heater puts out water between 1,400 and 1,800 degrees C, which is counterproductive to separating the oil from the water, causing it to flow down the drain.

GTAA business partners approached the restaurant owners and operators to get records and information on how often they were cleaning their grease interceptors.

There was limited success tracking the establishments, and holding restaurants accountable was difficult. Several of the restaurant drains tied into the main lines and at that time the GTAA did not have any standards covering what was allowed to go down the drains.

Subsequent research of oil separation technology revealed limited improvements with the use of passive oil separators. It also found a new type of grease recovery device manufactured by Clearflow Environmental Technologies in the UK. It was marketed and sold in the US and Canada under the name Goslyn. The unit instantly separates fat and oil at the source, collects food particles in a removable strainer, and doesn’t store fats or oils. This eliminates decay and improves hygiene.

More evidence

To ensure this product was the right solution to the problem, further evidence was required. The GTAA is a member of Partners in Project Green. With its help, valuable information was acquired from municipalities. The maintenance teams wanted to see scientific data and standards for oils and fats, biochemical oxygen demands, total suspended solids and PH levels. Goslyn provided all the required information and also supplied a list of several of their installations.

After several site visits, the teams were confident enough to install the units.

Superheated water was diverted from the dishwasher into the Goslyn units, which allowed better control of grease going down the drain lines. The units, and a new dishwasher discharge water-piping configuration going into the unit were added to the Tenant Design Standards for all new GTAA tenants.

The airport has also implemented a recycling program. Oil is collected and moved offsite and repurposed for bio diesel and other uses at a net zero cost to GTAA restaurants.

What started out as a modest initiative to improve the reliability of the airport’s plumbing infrastructure turned into a large-scale project, which addressed all the failures that were encountered. Its initiatives met the three criteria of sustainability: social, environmental and economical, which put Lester B. Pearson International Airport’s water sustainability a step ahead.

Steve Gahbauer is an engineer, a Toronto-based business writer and a regular contributing editor. E-mail

This article originally appeared in the May-June 2018 print issue of PLANT.


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