STUDY OF KELAY RIVER’S INFLUENT SCENARIO WHICH AFFECTED BY COAL MINING ACTIVITIES USING THE STREAM MODEL APPROACH IN BERAU, EAST KALIMANTAN.

• Main Author: Salsadila, Alifya
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/68818
• Institution: Institut Teknologi Bandung

Open pit coal mining is a surface mining technique in which coal is extracted by excavating, hauling, and stockpiling overburden to a disposal area. This activity has the potential to cause changes in topography and land cover. Oxidation of sulphide minerals from overburden has the potential to produce acid mine drainage, which has low pH and contains SO4 2- , Fe2+, Al3+, and Mn2+ compounds. QUAL2Kw, one of the stream models tools, is a mathematical model used to estimate the cause-and-effect relationship between the pollution load entering the river and water quality in different scenarios. There are four scenarios of influent conditions being modelled. In scenario 1, pH = 6 and TSS = 300 mg/L from point sources meanwhile the diffuse sources are under existing conditions. Scenario 2 has pH = 6 and TSS = 300 mg/L at point sources and diffuse sources. In scenario 3 the conditions are the same as in scenario 1 but the pH value = 9 and TSS = 30 mg/L. Scenario 4 modifies the pH and TSS at the point sources and diffuses sources to pH = 9 and TSS = 30 mg/L. From the four scenarios, the modelling results show that the simulations carried out in scenarios that do not modify the value or concentration in the diffuse sources do not significantly impact changes in concentration or value in the Kelay River flow. On the other hand, if the concentration at the diffuse sources is changed, the changes that occur are more obvious. The small discharge that enters from the point sources to the Kelay River, when compared to the discharge from the diffuse sources, can be the main cause. Therefore, efforts to keep the pH and TSS concentration below the Quality Standards must not only be carried out at the point sources but also control the flow concentration from the diffuse sources.