Akron-Canton Airplane Deicing System

23044.00 a k r o n - c a n to n a i r p o r t De i c i n g s ys t e m North Canton, Ohio Engineering Sustainable Practice 2008 o u ts ta n d i n g ac h i e v e m e n t awa r d e n g i n ee r i n g E xc e l l e n c e Awa r d s The American Council of Engineering Companies, Ohio

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To an air traveler scheduled to depart in the middle of a winter storm, the sweeping arms of the deicing truck spraying the aircraft before takeoff is a welcome sight.

Because this process makes air travel safe in treacherous weather, passengers are glad this process exists. But they probably don’t consider what happens to the deicing fluid, the primary constituent of which is propylene glycol, after it is sprayed onto the aircraft.

Akron-Canton Airport (CAK) in

North Canton, Ohio, has served record-breaking numbers of passengers over the last several years, and has seen a rapid expansion in its aircraft operations as a result. Up to 3,000 aircraft per month are deiced each winter, with 300 to 500 gallons of deicing fluid applied to each aircraft. If significant quantities of the applied propylene glycol reach streams through the airport’s drainage system, the aquatic life in the water can be negatively affected.

Prior to 2007, the airport did not have a system in place for managing the environmental impacts of deicing fluids.

In response to the EPA’s National Pollutant Discharge Elimination System (NPDES) permit program, CAK engaged the project team, led by RS&H, in 2004 to evaluate the effectiveness and cost of potential deicer collection, storage and treatment systems. The system chosen is a state-ofthe-art facility that is only one of three systems of its kind currently operating at airports worldwide.

It consists of three components: (1) two containedarea aircraft deicing pads, (2) a deicer/storm water collection and storage system including

two 750,000-gallon concrete storage tanks, and (3) a deicer fluid treatment plant featuring Anaerobic Fluidized Bed Reactor (AFBR) technology.

“Before starting,” GS&P project engineer Tim Arendt, P.E. explains, “the team built a sophisticated computer model in our Columbus office to simulate all the various possibilities for the different system elements. We looked at a lot of possibilities utilizing this homegrown model and basically found the system combination that would meet the client’s regulatory obligations while minimizing cost.”

The deicing pads include several in-pavement catch basins that capture the effluent, or runoff and overspray, and route it to diversion structures, as well as a system for monitoring the concentration of pollutants in the deicer fluid. Depending on the level of contaminants found, diversion valves release the effluent either directly into the storm sewer or to storage tanks for detention prior to treatment.

It was imperative that the tanks neither interfered with airport operations nor became aesthetically unbearable for neighboring communities. They were

Cover GS&P performed the modeling for sizing of the storage tanks. The tanks are partially buried and conceal the bulky 750,000-gallon structures which hold up to 1,500,000 gallons of glycol-contaminated water known as effluent. The positioning of the tanks allows gravity to guide the flow through the drainage system, avoiding interference with airport operations and minimizing the visual impacts of the tanks on the surrounding community.

partially buried in an area that slopes downward from the main airfield, leaving only the domed roofs of the bulky 750,000-gallon structures exposed.

well as in business and industry-related media, the project has received an overwhelmingly positive response for its innovation, cost-effectiveness and green design. Local congressional representative Ralph Regula noted, “As a matter of public safety The team chose the AFBR and responsible environmental treatment method due to its stewardship, the Akron-Canton “The advanced engineering ability to treat high concenAirport is moving in the right in this system will surely be trations of glycol-contaminatdirection with the introduction helpful to airports around ed effluent at a low operating this new technology to its the country that are looking of cost and its environmental operations.” to CAK as a model to build benefits. Prior to treatment, their own deicing systems.” “This system goes beyond simply the effluent is heated and is then run through two 10compiling with State mandates — Rick McQueen, foot diameter, 32-feet high for water discharge by setting a Akron-Canton Regional Airport Director bio-reactors. Both reactors new standard in environmencontain a community of tally friendly processes and anaerobic bacteria which “eat” the glycol, removrecycling,” said airport director Rick McQueen. ing it from the contaminated runoff. Methane gas, “The advanced engineering in this system will a by-product of the bacterial buffet, is captured surely be helpful to airports around the country and burned in the plant’s boilers to heat incoming that are looking to CAK as a model to build their effluent and the building itself. The sustainable own deicing systems.” process nearly eliminates the plant’s reliance on external fuel sources.

As CAK continues to grow and expand as one of the Midwest’s busiest airports, the vast improveThe deicer management system serves as a model ment to its deicer management capabilities will for effective, sustainable engineering.* Covered stand as testament to the very best in engineering, extensively by local and regional news sources, as design and civic responsibility. ■

Propylene glycol is a colorless, odorless liquid soluble to various extents in a wide range of organic materials.

Although propylene glycol is used in benign concentrations in things like carbonated beverages, salad dressings and baking products, its biodegradation in streams can result in oxygen depletion, resulting in ecological harm to aquatic plants and fish.

Molecular formula: C3H8O2

*How it works: glycol, which also is used in many household products removes snow and ice from planes. But glycol also removes oxygen from water that can cause ecological harm to stream plant life and fish. The run-off flows into a drainage system where it is stored in two storage tanks constructed to hold glycol contaminated water known as effluent.

The Anaerobic Fluidized Bed Reactor System (AFBR) uses a biotic community, the bugs, to eat the glycol out of the effluent. It’s first pumped into the treatment plant, heated and ran through a large reactor where the bugs eat the glycol leaving the water. The water is then re-oxygenated and released into a detention pond downstream.

There are two by-products of this process: bio-sludge and methane gas. The small amount of bio-sludge is dehydrated through a gravity sand filter, which uses no external power, while methane is reclaimed and burned in the plant’s boilers to heat the incoming effluent and the building itself. This process almost eliminates the plant’s reliance on fossil fuels and allows it to operate with minimal additional costs to the airport. The building was designed by Reynolds Smith and Hills Inc. while the glycol treatment system was completed by GS&P. As for the little bugs, they hibernate in the summer when they’re not being used. A little sugar helps the biotic community grow and restores the bugs again for next winter.

Gresham, Smith and Partners provides design and consulting solutions for the built environment that contribute to the success of national and international clients. For more than 40 years, GS&P has focused on enhancing quality of life and sustainability within communities. GS&P consists of industry-leading professionals practicing architecture and engineering design as well as scientists and highly specialized planning and strategic consultants in Environmental Compliance, Aviation, Corporate and Urban Design, Healthcare, Industrial, Land Planning, Transportation and Water Services. GS&P consistently ranks among the top architecture and engineering firms in the United States. For more information regarding GS&P, visit www.gspnet.com.

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