We analyze and evaluate a correlation of total coliform and building data on a monthly basis in the basin of Oita and Ono River. In addition, we analyze and evaluate an optimal range to use the building data from the total coliform's observation points, and the optimal attributes (number, area, total floor area) of building data. As a result of the analysis, we found that the correlation of total coliform of June and building data is high, and the correlation is high in the case of using the building data of about 7km radius and the total floor area.
