There are many cases which entrust the operation and maintenance of public facilities to private sectors or organizations in recent years. The main purpose of the consignment is cost reduction. The sewage facilities are the representatives of such consignment. Although such consignment lowers expense in the short term by reduction of labor cost, there would be a risk of increasing expense of the public service from a long-term viewpoint. That is, this comprehensive private consignment has an agency problem. This paper points out the effectiveness of information sharing systems for improving asymmetry of information, and the necessity for standardization of information and widening the area. This paper proposed the one direction of the systems, that is, utilizing Web2.0 technologies.