Glycol Recovery in the Golden Horseshoe

The Golden Horseshoe, whose name is derived from the region’s historical wealth and prosperity and the characteristic horseshoe shape, is one of the most populous regions in southern Ontario, Canada. It boasts more than seven million, nearly 60 percent of Canada’s entire population and is home to Air Canada, the world’s 11th largest airline.

Headquartered in Montreal, Air Canada spearheaded the implementation of a country-wide ADF environmental program and is the only carrier to have glycol blending systems in Canada.


Why is so much attention paid to deicing? One reason — safety. Since 1968, at least 10 takeoff accidents in North America have been attributed to wing surface ice contaminations. “NASA’s research has shown that as little as 0.8 of a millimeter of ice on the upper wing surface can knock 25 percent off an airplane’s lift and increase the drag,” says Roy Rasmussen, head of the ground deicing program at the National Center for Atmospheric Research (NCAR) in Boulder, CO.

To ensure safety, removing snow and ice from aircraft is an everyday part of airport winter operations and large quantities of propylene glycol and ethylene glycol based products are used to deice the aircraft. However, due to runoff and toxicity concerns, regulatory agencies such as the Environmental Protection Agency (EPA) and the Canadian Environmental Protection Act have set guidelines for exceedence levels. In Canada, glycol runoff cannot exceed 100 milligrams per liter.

Glycol recovery and recycling processes began in the early to mid 1990s. But it’s only been in the last two and a half years that Air Canada has been working closely with Aircraft Deicing Solutions (ADS) in conjunction with Inland Technologies to set up both stationary and mobile glycol blending stations to not only increase environmental protection but to significantly reduce costs. “Deicing is a tough area to save money because it’s directly related to safety,” says Bruce Johnstone, manager of ground safety and winter operations for Air Canada. “However, in this case, we were able to save money without compromising safety.”


The volume of chemicals used can have significant impacts on the surrounding environment, which is why Air Canada led the execution of a country-wide program for the collection and recycling of glycol effluent three years ago.

“Air Canada and the other Canadian carriers have a contract with Inland Technologies to collect and recycle all the waste chemicals at eight of our largest stations,” says Johnstone. “In a typical year, we can collect over 30 million liters of effluent, which would have an absolute huge environmental impact if left alone.”

Of course a fundamental concern for the airlines is cost. And one of the most expensive aspects of the deicing business has been shipping glycol, primarily due to the wonted 50/50 blend. Historically, Air Canada purchased a “ready-to-use” deicing product from Dow Chemical known as XL54. XL54 contains 45 percent water and 54 percent ethylene glycol, the freeze point suppressant chemical used to remove snow and ice from the wings and leading edges of the aircraft. “As a ready-to-use product, XL-54 covers us for the worse case scenario weather conditions — down to minus 33 degrees Centigrade,” says Johnstone. “Luckily for us, even in the great white north, there are relatively few days where this level of temperature protection is needed.”

Considerable savings are available by purchasing unadulterated glycol and blending it on site, thus reducing transportation costs and storage requirements. A unit called the GlycolPro™ takes a concentrated or “neat” deicing fluid product and mixes it with water based on the temperature and weather requirements at the time of flight operations. “This is a significant departure from the way things have happened in the past,” says Johnstone. “By purchasing a neat ADF and blending it on site, we’re able to save money on transportation, storage, chemical purchases and environmental clean up.”

Johnstone used the example of Ottawa International Airport, where a system was recently installed to illustrate how savings are generated. In an average season, Air Canada will dispense 750,000 liters of ready-to-use deicing fluid at this station. Of this volume, about 325,000 liters are water. “Our transportation fees are five cents per liter right now. By purchasing a neat deicing product that Dow had available, we’re saving around $16,000 in transportation fees alone,” says Johnstone.

“Buying a neat deicing product offers even more ways to save,” adds Johnstone. The deicing fluid manufacturers have prepared a set of data charts called LOUT tables. LOUT, or lowest operational use temperatures, specify the level of deicing agent in the mix required to safely deice an aircraft at various temperatures. “Rather than deicing as if it’s minus 33 degrees Centigrade all the time, we’re deicing based on what is needed,” he says.

An analysis of the weather patterns for Ottawa showed a 20 to 25 percent reduction in deicing fluid consumption was achievable by taking into account outside ambient temperatures [OAT] at the time of flight operations in Ottawa.

“A 20 percent reduction in total consumption is 150,000 liters. Even if we take a minimal chemical fee of one dollar per liter, we’re saving $150,000 a year,” says Johnstone. “For the low capital investment required for this system, the decision is a no brainer, and a system-wide roll out is underway.”


At present, Air Canada operates seven blending stations throughout Canada including Halifax, St. John, Calgary, Ottawa, Toronto, Winnipeg and Edmonton. During the summer, there is an average of two to four employees at each station. In the winter months, November until the end of May, that number usually increases to eighteen.

The first station in Canada to install the GlycolPro™ was Calgary. The local carrier consortium was looking for ways to reduce costs associated with the 1.5 to 2 million liters of ready-to-use ADF sprayed per season at the airport. Fluid blending equipment was the solution. “We were quite interested in fluid blending because of the potential savings,” says Ian Anderson, manager, ground icing & winter operations for Calgary-based WestJet. He explains that significant savings are available on the transportation front. “We no longer have to pay to transport water,” Anderson says. “Buying neat fluid has a trickle down effect in that storage and handling costs are also reduced.”

As always, training and safety are a crucial element to any new technology. New procedures need to be carefully monitored. According to Johnstone, next season, after the learning process has fully taken hold, they will start aggressive blending. In doing so, Air Canada wants to be certain that personnel know what is required. For the highest possible efficiency, glycol concentration levels need to be monitored closely to be safe yet still meet the preferred LOUT (lowest operational use temperature.) “We plan to install truck-mounted

in line refractometers that give a reading of the glycol concentration level. This way the operators know what is required and what they are dispensing, Johnstone says. “Our standard practice is to err on the side of safety.”

To enhance the safety procedures, “Glycol Mitigation Plans” have been installed at all major Canadian airports which subsume qualified deicers, number of deicing trucks, type of tanks and the standards required. The mitigation plans are required as part of a government monitoring system to Transport Canada. The impact of this new equipment and deicing program management will impact positively on the “Glycol Mitigation Plans.” The plans detail specific ways that current environmental legislation will be followed. Airport authorities manage the plans, but the carriers are all signatories.

“Air Canada, WestJet and other Canadian carriers operate under two pieces of strict federal legislation that have a significant impact on how we deice our aircraft,” says Johnstone. “CEPA, or the Canadian Environmental Protection Act and the Fisheries Act both make specific demands of how the runoff from deicing operations must be controlled.”

Section 53 of CEPA states: “The responsible federal department should ensure that the discharge of glycols into surface water resulting from aircraft deicing and anti-icing activities at a federal airport does not exceed a concentration of 100 mg/L.” Sub Section 36 of the Fisheries Act states, No person shall deposit or permit the deposit of a deleterious substance of any type in water frequented by fish. According to Johnstone, that means no glycol.

CEPA guidelines are criminally enforceable under the Fisheries Act. The legislation is strong enough that the carriers and deicing service providers that make up the Canadian airline industry work to ensure strong environmental programs are in place.

“We have an amazing record of meeting the guidelines set out in the environmental legislation, but the GlycolPro™ and using less ADF helps us take our corporate stewardship goals one step further.”


Blending to temperature has been used in Scandinavia for years. Overall, carriers see about 20 percent savings in fluid costs in a season. At that rate the equipment investment is generally recovered in a very short time. And between the cost of shipping and the blending to temperature, Air Canada saves $350,000 each season.

In the future, they hope to come “full circle” in Canada with the recovery process, where they not only recover the ADF but polish it and put it back on the aircraft.