Abstract
The statistical analysis used by the observed data is attempted in this paper to present the degree of influence on the groundwater for chemical grouting coagulants such as water glass type liquid chemicals. The water qualities are investigated at observation wells in the vicinity of sewerage construction. The modified data excepting the characteristics of circumference are reevaluated in new independent variables which are exchanged the observed water quality items depend on each others.
The modified data induced by principal component analysis are clearly classified into the contaminated, the non-contaminated and the intermediate water quality groups. The data on intermediate group are dispersed in the boundary zone placed between the two groups.
The relationship between the principal component and the observation variables will be explained as follows ; the first principal component represents the degree of pollution by coagulant constituents such as Na, SiO2 and M-alkality, the second principal component total hardness and the third principal component pH. And it is shown in the groundwater qualities contaminated by the coagulants, the values on first and third principal components are increased in opposite the second principal components. During the short period when coagulants are injected into groundwater, Na, SiO2, M-alkality and the total hardess increased concurrently to form the intermediate group. Only in analysis of the contaminated group, the principal component axis is rotated for clarification and the result is obtained where pH and RpH correspond to the second principal component and total hardness corresponds to the third principal component.
