Estimation of the Sources of Groundwater Used for Food Materials in Sayama City, Saitama Prefecture, by Geochemical Methods and Numerical Simulation

Understanding of the source and chemical characteristics of groundwater provides important strategies for the quality management of mineral water and food materials. To identify the source of groundwater used for food materials, water chemistry and stable isotopes of hydrogen and oxygen were examined in well-water from Sayama city, Japan. The well-water samples had similar chemical characteristics to river water in the west-rim of the Kanto plane. The hydrogen and oxygen isotopic ratios of the well-water samples indicated that their origin was solely meteoric, and that the groundwater mainly originated from upstream of the Iruma River (and other rivers) in the west-rim of the Kanto plane. A subsequent groundwater simulation produced down streamlines from the upstream areas of the Iruma River that correspond well with the groundwater flow estimated from the δD and δ18O values of the samples. Thus, the stable isotopes and water chemistry of the sampled water, groundwater flow simulation appears to be useful tools for tracing the origin of groundwater used for food materials.