Protecting areas of Water
Water, as understood by the German Water Act, includes all surface waters and the ground water. It is one of our company's key concerns to protect these waters while operating the airport, as they are the basis of the existence of humans and a habitat for plants and animals. To improve water protection and to minimise the pollution levels of the waste water resulting from airport operations, we take the following measures:
- Minimisation of precipitation run-off from the runway and apron by constructing rainwater reservoirs
- Minimisation of the pollution levels in the waste water by making sparing use of less environmentally harmful de-icing agents for aircraft and the runway, and by feeding rainwater containing de-icing agents into the City of Dresden's public sewage system
- Reducing drinking water consumption, including by building and operating a rainwater treatment plant
- Removal of soil contamination from the former airport tank farm
The airport operates a rainwater treatment plant in which rainwater from about 5 hectares of roof surfaces is collected in tanks and supplied to consumers all over the airport site. This water replaces valuable drinking water for toilet flushing, in air conditioning systems, as fire water, for sewer cleaning and to water the green areas.
Dresden Airport is situated on an elevated plateau. The rainwater drains off to the catchment areas of Schelsbach, Seifenbach, Promnitz and the Ruhlandgraben stream. Considering that the sealed surface area at the airport amounts to about 90 ha, rainwater utilisation is of great importance.
The rainwater is collected in drainage systems and is either discharged directly into surface streams or into the municipal rainwater collector, or it simply seeps away. Rainwater storage reservoirs in all catchment areas are used to reduce the peak run-off from hard surfaces into the surface waters. The quality of the collected rainwater depends mainly on the usage of the surfaces (roof surfaces, car parks, roads, apron, taxiways and runway).
There are special requirements for the prevention of accidents in the rainwater drainage process. We have taken the following measures:
- The tank farm surfaces are connected to the drainage system through a system of light oil traps, retention tanks and gate valves for safety reasons.
- All storage areas for substances hazardous to waters, such as diesel, de-icing agents and fire extinguishing agents, meet the strict requirements of the environmental laws.
- Surface water from the apron, where aircraft are handled and fuelled, must also pass through clarification tanks before being discharged. The airport fire brigade has a special implement truck on permanent standby to prevent oil from leaching away if the fuelling equipment is faulty.
- In an emergency, the entire drainage system for the runway and taxiways can be shut off. In such cases, polluted water will be retained in backwater channels and can be disposed of properly, depending on the results of sample tests.
Water drained off the 60 hectares of runway and taxiway surfaces may contain de-icing agent in winter if temperatures are very low, because both aircraft and hard surfaces are de-iced using chemicals.
- The sparing use of de-icers and the use of less harmful substances are operational measures which help to reduce water pollution levels.
- The condition of the runway is permanently monitored by a black ice early warning system. This allows us to apply surface de-icers preventively and therefore to reduce the quantities used.
Our operational measures are also coupled with technical measures. The quality of the run-off water is tested and the levels in the backwater channels are measured by an automated process control system. If conductivity or TOC (total organic carbon) content limits are exceeded in one of the online measuring points, automatically controlled rainwater gates deliver the rainwater that is polluted with de-icers into the sewer for treatment in the sewage works.
Dresden Airport has a separate system for sewage and rainwater collection which is linked to the City of Dresden’s public sewage system.
- Wastewater from kitchens, workshops and the vehicle washing plant is pre-treated before it is discharged into the sewage system.
- Wastewater from the passenger and office buildings is similar to domestic wastewater.
- Most of the wastewater from aircraft is faecal water which is separated from solid matter in a pre-treatment plant and discharged into the public sewage system.
The final treatment of this wastewater takes place at the municipal sewage works in Dresden-Kaditz.