Aviation has long been the 'enfant terrible' of the environmental movement with the increasing number of fights blamed for dramatically forcing up greenhouse gas emissions. One of the main concerns for green campaigners is the size of the airports needed to handle all the world's extra traffic.

Many airports are reacting to those concerns by not just reducing their emissions through the likes of more environmentally-friendly lighting and more efficient buildings but also by creating wildlife areas.

For airports, wetlands make good environmental sense but also fulfil an important operational role by allowing the efficient treatment of polluted water.

One example is the UK's Heathrow Airport which earlier this month awarded environmental engineers ARM Group and wetland consultants Naturally Wallace a contract to upgrade its wetland treatment facility at Mayfield Farm.

The contract follows a successful 2009 trial of its forced bed aeration (FBA) technology, which forces air through reed beds in order to improve its effectiveness in treating water.

ARM's director Tori Sellers said that wetland treatment works are essential for airports like Heathrow because they offer ways of handling de-icing solutions, such as glycol, acetate or potassium which must be used during extreme weather conditions.

Naturally Wallace's president, Scott Wallace said: "By aerating the lagoons and introducing FBA to the reedbeds, the system has become up to 14 times more effective. Additionally, Heathrow will benefit from long-term cost and energy savings."

Heathrow is not the only airport engaged in managing wetlands. In Australia, for instance, on the northern side of Botany Bay in Sydney's Eastern Suburbs, a wetlands area has been protected by organisations including the airport authority.

It covers 58 hectares, consists of 11 interconnected ponds and is listed as significant in the Directory of Important Wetlands in Australia.

Sydney Airport manages the section of the Botany Wetlands known as the Mill Pond, East and West Engine Ponds and the Mill Stream, collectively known as the Sydney Airport Wetlands and home to native flora and fauna species including reptiles, fish and birds as well as migratory birds protected under international conservation agreements.

To protect the site, managers have carried out work including preventing any pollutants to enter the area, installing a fish ladder to allow movement of native fish from Botany Bay upstream into the wetlands and the revegetation of a section of the East Engine Pond with native plant species.

Other airports engaged in such work include, in the United States, Buffalo which needed to treat 1.2 million gallons/day of stormwater laden with deicing fluid. The solution was a wetland system because it was an effective treatment and could handle seasonal variations and integration into the existing stormwater management system. And in Canada, Edmonton International Airport (EIA) has experienced double-digit growth which has led to an expansion of the airport, including expanding the existing wetland treatment system for handling the increase in deicing fluid.

Environmentalists do, however, caution that the measures taken by airports to protect wildlife and reduce emissions should not obscure the overall impact of aviation.

Jean Leston, Head of Transport for campaign group WWF, while welcoming such schemes, said: "We are saying that these carbon neutral projects make airports look green but they ignore the elephant in the room. There is a bigger picture here.

"Our view is that aviation travel is growing at an unsustainable rate and we need to reduce the amount of flying. If you going on a business trip, do you need to fly or can you do it by video conferencing or take the train? If you are going on a holiday which involves flight maybe you can balance it out with the next one that does not?"

She said such a measure would allow airports room for some growth but not the massive expansions being seen at the moment.

Top Image Credit: Heathrow Terminal 5 ©