Abstract
A 36-years-old laboratory refurbished at 2005. A new rain recycling system was installed and operated these 1.5 years. In 2006, 1700mm rain was felled at Yokohama area. 80% of rain was collected and used in the system. The quantity of rain water was about 400 m3 from 300 m2 roof and the quality of treated rain water was kept safety level in coliform, egionella content and other factors.