In 1960 vacuum consolidation method was firstly introduced in Japan but it was not popularly used due to many problems such as imperfection of airtight condition, low vacuum pressure, high operation cost due to long vacuum pumping period, drain clogged. Since 1988, MIC has started to develop the system to overcome the problems. In 2002, Air-Water separating system was introduced and help us to maintain high vacuum pressure over 70-80 kPa along the consolidation process. The standard area and volume of improvement is about 4,000~6,000 m2 and 60,000 m3 per vacuum pump.