In 1982 the Environmental Agency conducted the preliminary nationwide survey for groundwater. Then, regarding tetrachloroethylene (PCE), about 4. percent samples of the total 1,499 ones exceeded the guideline of WHO about drinking water quality. On the other hand, in 1984 N-Ward in Tokyo metropolitan Government (TMG),12.8 percent of samples with PCE also exceeded the guideline. It is important to grasp the situation of groundwater pollution and then to find out causes and countermeasures. The purposes of this study are to grasp the temporal variation of the situation of groundwater pollution, to investigate the resident consciousness for groundwater quality by an questionaire, and applicably to analyze the policy for selecting the method of countermeasure in the urban region such as N-Ward in TMG.