NETDA enjoys good environmental quality and normally balanced ecology. The quality of water in the Yangtze River, inland streams and phreatic layer is fairly good. Atmospheric monitoring of sulfur dioxide, ammonia-oxide and suspended particles shows that the atmospheric environment here is up to the requirements for first-class in the State standards. The recorded environmental noise is 43.5db, better than 45bd - generally accepted as specified by National regulation for special residential quarters. The environment here is peaceful and secluded, the natural radioactive background (r' ray) is averaged at 17.5 micro-roentgen/h, and there is no artificial radioactive contamination.