Heavy Metal Pollution Index for Assessment of Seasonal Groundwater Supply Quality in Rural Area, Kalasin, Thailand

Abstract

Agriculture is the major activity in most rural areas in northern Thailand. The aim of this study was to assess the heavy metal pollution index (HPI) for water supply quality in rural village named Bannongvang village locates in Kalasin province. The concentration of heavy metals including iron (Fe), manganese (Mn) and zinc (Zn) have been analyzed for eight sampling stations in the study area by atomic absorption spectrometer. The results were evaluated in accordance with the drinking water quality standards suggested by the World Health Organization and Thailand Department of Health Standards. All sampling stations in the village in dry season were noted in the suitable range for drinking purpose, but almost stations in rain season exceed the permissible limit for drinking purpose. The values of HPI based on the mean concentration in rain and dry season were found to be 96 and 57, respectively. The HPI values in dry season were low heavy metal pollution for all sampling stations and lower than critical index value for drinking water (HPI<100). However, the HPI of each individual sampling station showed the high values in rain season, thus indicating that 37.5% of the samples are critically polluted with respect to heavy metals (HPI>100%). The results showed the water supply quality and the need for the development of preliminary water treatment before it was used for the household purpose.

Keywords: heavy metal pollution index (HPI), water supply, permissible limit, concentration, preliminary treatment.