Chinanews, Beijing, Oct 26 – Beijing plans to set up a pre-warning system to monitor the city's drainage system near the Olympic venues and key areas inside the city, to make sure that no poisonous gas will leak out to pollute the city's drinking water. The Beijing Olympic Games Organizing Committee requires that before 2008, about 30 such monitoring stations should be established in the city.The monitoring system can detect whether the hydrogen sulphide released from the drainage system has exceeded the set standard. Technicians will minotor the gas condition inside the drainage system and send the results to the monitoring center regularly. At present, the Beijing Water Drainage Group has started to set up some monitoring stations near the Olympic venues and some key areas in the city. So far, the project has been going on smoothly, said an official from the Beijing Water Drainage Group on Thursday.At present, Beijing's water drainage system in the downtown area measures 4,000 kilometers. In order to make sure that the city's water drainage system works well all the time, especially during the 2008 Olympic Games, the Beijing Water Drainage Group has introduced the world's most advanced water drainage equipment from abroad. It has also set up a GIS-based urban drainage pipe network information system and a pre-warning gas monitoring system to eliminate the possible dangers existing in the city's water drainage system. With these efforts, it hopes that the water drainage system in the capital city can operate well and the residents' public safety can be ensured.