Flughafen Zürich AG is entirely committed to water conservation as clean water is a valuable commodity.
Fresh water and wastewater
Thanks to the careful management of fresh water, water consumption per passenger has been significantly reduced at Zurich Airport over the past few years. Rainwater is also increasingly being harvested for toilet flushing.
All domestic wastewater from the airport is channelled to the wastewater treatment plant in Kloten-Opfikon (ARA). Wastewater from aircraft maintenance operations is pre-treated in an industrial wastewater treatment plant managed by SR Technics. Rainwater sewage is collected separately via an extensive drainage system, pre-treated where necessary, and channelled away into the river Glatt.
Wastewater from de-icing
In order to ensure safe flight operations during the winter months, aircraft and areas used for flight operations have to be cleared of snow and de-iced. De-icing products are used for this purpose (glycol for aircraft, formates for treating runway and apron surfaces). Zurich Airport is breaking new ground by using a natural process to purify the wastewater from de-icing operations. Wastewater that contains high levels of de-icing products is collected from aprons and taxiways and distributed across suitable green spaces through sprinkler systems. Micro organisms break down the de-icing residues contained in the wastewater, thereby purifying the wastewater until it no longer contains harmful levels of de-icing substances. This system has been in operation since 2001.
General drainage plan (GEP)
An officially approved general drainage plan (GEP) has been in place at the airport since 1999. This forms the basis for all plans related to water conservation.
Soil and contaminated sites
Good soil is a valuable commodity. The soil at Zurich Airport is constantly inspected and protected with suitable measures.
As part of the construction projects, the soil in certain areas of the airport is being constantly inspected. Soil conservation measures are undertaken as required. The main aim is to prevent compaction and ensure chemical/biological integrity. In the case of major excavation work, a soil expert is called in to provide professional support with the build. In extreme cases, e.g. exceptionally wet conditions, construction work may be halted to protect the soil.
An extensive study was conducted in 2006 to determine soil quality at the airport. This study confirmed previous measurements. Standards are predominantly being met. It has been known for some time, however, that the areas around the runways have higher levels of copper and zinc due to flight operations (caused by brake dust and rubber abrasion from aircraft). High PAH (polycyclic aromatic hydrocarbon) levels were identified in some areas, e.g. where snow is deposited in the winter. The scale of this pollution is comparable with busy streets or the centres of residential areas.
Various locations around the airport are designated as contaminated sites in the land register because they were formerly used for waste disposal or were sites of industrial activities or accidents. The land register is managed by the FOCA (see link). Most locations have now been thoroughly inspected and cleaned up where necessary. The largest project to date involved the restoration of a former fuel depot site in three stages from 2000 to 2005 at a cost of around CHF 7.8 million.