Spatial Variation of Electrical Conductivity, Total Suspended Solids, and Total Dissolved Solids in the Batang Arau River, West Sumatera, Indonesia

Abstract

This study aims are toanalyze the spatial variation of electrical conductivity (EC) values, total suspended solids (TSS), and total dissolved solids (TDS) concentrations along the Batang Arau River. Water samples were collected from eight stations along the river at biweekly intervalsbetween March and May 2014. The results indicate an increasing trend in the value of three parameters from upstream to downstream, reflecting the effect of natural and anthropogenic activities along the river. The EC values were in the range of 173-5,097 μS/cm and had exceeded the water quality standard established by World Health Organisation (WHO) at the downstream. The TSS and TDS concentrations were in the range of 76-2,078 mg/L and 124-3,560 mg/L, respectively. The TSS concentrations at all stations had exceeded the river quality standard of class II established by Governor Regulation of West Sumatera, while the TDS concentrations had exceeded only at the downstream area. Significant spatial variation of the EC and TDS concentrations was observed between the upstream-midstream and the downstream but was not obtained along the river for the TSS concentrations. It indicates that the anthropogenic activities along the river affected the variability of EC and TDS, but not for TSS. Based on these results, reducing the number of sampling points into three stations could be performed for the EC and TDS, while TSS monitoring at only one station could be applied.