ANALYSIS OF TOTAL MAXIMUM DAILY LOADS USING QUAL2KW MODELING (CASE STUDY: LESTI RIVER, KABUPATEN MALANG)

• Main Author: Ezar Adi Nugroho, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Sistem
• Online Access: https://digilib.itb.ac.id/gdl/view/77904
• Institution: Institut Teknologi Bandung

With the increasing population and changes in land use, the Lesti River in Malang Regency has shown signs of pollution, particularly concerning the Biochemical Oxygen Demand (BOD) parameter. The documents from IKPLHD Malang Regency in 2016 and 2018 indicate that the BOD concentrations in the Lesti River do not meet the Class II water quality standard of Government Regulation No. 22 of 2021 at several monitoring points. The BOD concentrations ranged from 3.15 to 32.05 mg/L in 2016 and from 4.21 to 15.35 mg/L in 2018, necessitating evaluation. The objective of this research is to conduct an evaluation based on the analysis of water quality conditions, Total Maximum Daily Loads (TMDLs), and the carrying capacity of the Lesti River for the BOD parameter using the QUAL2Kw software. The QUAL2Kw software is utilized to comprehend the characteristics of the Lesti River and model various scenarios to determine the extent of BOD pollutant load reduction required for the Lesti River to meet the prescribed water quality standard. From the results of pollutant source identification, it is shown that the potential total BOD pollutant load entering the Lesti River is 14.94 tons/day under existing conditions and 15.17 tons/day in 2028, categorizing the Lesti River as moderately polluted for the BOD parameter. The modeling results indicate that if the water quality standard for the Lesti River is Class II, then the Total Maximum Daily Loads (TMDLs) for BOD in the Lesti River amount to 6,397.05 kg/day with a negative carrying capacity value. Therefore, the pollutant load from the Lesti River needs to be reduced by 8,776.51 kg/day in 2028 to ensure that its water quality meets the prescribed water quality standard.