Water Quality Assessment Based on National Sanitations Foundation Water Quality Index during Rainy Season in Sibelis and Kemiri Estuaries Tegal City

Abstract

Abstract Sibelis and Kemiri are two important river estuaries in Tegal City, at the northern coast of Central Java. Both estuaries have differences in sources of pollution. Pollutants in Sibelis estuary come from industrial activities, such as the fillet household industry, fishing ports, and domestic pollution. While pollutants of Kemiri estuary come from pond fisheries, agricultural activities, and domestic pollutions. This study aims to assess the water quality of the Sibelis and Kemiri estuaries during the rainy season based on the Water Quality Index of the National Sanitation Foundation. The research was done on January–March 2019 (rainy season) with three sampling stations. Each station was divided into three sites. Eight water quality parameters were measured i.e. temperature, TDS, TSS, pH, BOD5, DO, PO4 and NO3. The results showed that there was an increasing trend in the NSF WQI Index in Sibelis from January to March 2019 (48.02 to 51.25) and included in the poor quality category (49.61). Based on the Indonesian Ministry of Environment Standards (2004), six parameters were out of standard, namely TDS, TSS, BOD5, DO, PO4 and NO3. While the results of Kemiri estuary show a decreasing trend from January to March 2019 (62.36 to 57.88) and fall into the medium quality category (62.08). Only four parameters have outside standards i.e. TDS, TSS, PO4 and NO3.