[O-08] Poster presentations by senior high school students

[O08-P79] Source estimation of E.coli bacteria in the spring water of Otomeyama Park by E.coli survey and chemical

*Takuto Uchida¹, *Koki Sato¹, *Katsuto Nakasute¹, *Kensuke Minamide¹ (1.Kaijo Senior HighSchoolchool)

Keywords:Spring Water, E.Coli, Groundwater, Otomeyama Park

It has been suggested that the spring water in Otomeyama Park contains E. coli bacteria. Therefore, in this study, we wanted to estimate the source of the bacteria. In this study, we hypothesized that the E.coli bacteria was caused by a leak in the nearby sewage system or by animals in the park. To verify this hypothesis, water samples were collected four times at three different locations, and four chemicals commonly found in sewage were measured by LC/MS/MS, and the amount of E.coli was measured by culturing on an Agar medium. As a result, E.coli was detected. The results also showed that chemicals that are difficult to decompose underground were detected, but not those that are easy to decompose, indicating that although sewage was contained, the leak was not in the neighborhood. Based on measurements of the recharge area in previous studies, it can be assumed that the leak is in the Nerima area. However, (except the results from the spring outlet), the amount of E.coli was higher than in other springs where leakage from groundwater was observed. This led us to believe that sewage leakage was much less common and that the main source of E.coli was mainly from animals in the park.