Distribution, source identification, and assessment of heavy metal pollution in the surface and pore waters of...

The Cipeles watershed is the largest subsystem of the Cimanuk watershed, which is located in an agricultural area. Some segments of the Cipeles River are appropriate for aquatic life habitat. To assess the pollutant risk from heavy metals, which tend to accumulate in the environment, this study determined the heavy metal concentrations as a basic database, calculate the heavy metal pollution index (HMPI), and assess the correlation between heavy metals from the surface and pore waters of Cipeles River. Samples from 11 sampling stations at the end of the wet season were collected, preserved, and characterized using inductively coupled plasma mass spectrometry. The heavy metal concentrations were then plotted on a map using a geographic information system. As a result, the heavy metal occurrence in pore water was found to be Mn > Fe > Ba > Co > Zn > Cu > Pb > Cr in the order of abundance, while the order was slightly different in surface water, i.e., Fe > Mn > Zn > Ba > Cu > Pb > Co > Cr. Both pore and surface waters showed similar dominance for iron and manganese, where they mostly originated from the run-off water from the laterite and alluvial soils at the sampling locations. The other micro-concentrations of heavy metals indicate the anthropogenic source of pollutants. The HMPI indicated a low level in the upstream area, medium to high levels in the city center, and high levels in the downstream area. Moreover, there is a significant correlation between the heavy metal concentration at pore and surface waters, especially for Mn and Co in the city area and also Zn and Ba in the downstream area.