Abstract

The uranium concentrations were determined in groundwater collected from 3,820 community groundwater system (CGS) located in remote rural areas where access to the nationwide water work is not easy. The frequency distribution of uranium concentrations shows a lognormal distribution which is common in most radionuclide surveys. The measured maximum uranium concentration was 1,757.0 μg/L with an average of 6.46 μg/L and a median of 0.76 μg/L. When grouping the uranium concentration results of CGS into 10 geological units, the median uranium concentration was high (0.99-2.05 μg/L) in three granite areas, and low in sedimentary rocks areas and porous volcanic rocks areas (0.04-0.50 μg/L). Of the 3,820 samples, 3.8% are above the guideline value of 30 μg/L (WHO, 2011). On the other hand, the exceeding rates of JGRA and PGRA CGS are 8.5% and 7.5%, respectively. Therefore, attention should be paid for the development of new CGS along with the management of the existing CGS in JGRA and PGRA areas.

Keywords uranium, concentration, groundwater, community groundwater system