Simulation of pollution load capacity using QUAL2Kw model in Kali Surabaya River (Cangkir-Sepanjang segment)

The Utilization of Kali Surabaya River as water resources for drinking water is constrained by pollution from domestic and industrial waste and agricultural activities around the river banks. This study was aimed to calculate the pollution load capacity using QUAL2Kw model which presented the water quality. Study area from upstream (Cangkir) to downstream (Sepanjang) of the river was divided into 3 segments. The required data included primary data by sampling at determined points representing the condition of pollutant source. Secondary data included climatology, population, river hydraulic, and discharge and quality of pollution obtained from related institution. The water quality parameters analysed were BOD and COD, where the result exceeded the water quality standard of class I, while the DO was less than the standard requirement. Based on the simulation result, the value of pollutant load in each segment for BOD was 12,416 kg/day, 23,180 kg/day, and 17,759 kg/day while COD was 56,158 kg/day, 99,188 kg/day, and 74,316 kg/day. Then, the capacity of BOD in each segment was 1,681 kg/day, 1,138 kg/day, and 1,398 kg/day while COD is 12,396 kg/day, 8,150 kg/day, and 9,681 kg/day. This means that the pollutant load has exceeded the capacity of the river.