DESIGN OF UBRUG WATER TREATMENT PLANT IN PDAM PURWAKARTA

• Main Author: Fathur Rofi, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46584
• Institution: Institut Teknologi Bandung

Abstract. Purwakarta City System which consists of five districts namely, Purwakarta District, Jatiluhur District, Babakancikao District, Bungursari District, and Pasawahan District are one of the areas that serve by Purwakarta PDAM services. Purwakarta City System has reached 79% at the services which is served by several water sources including Jatiluhur Reservoir (Ubrug Water Treatment Installation), Cilembangsari Spring, Cigoong Spring, Munjul Well, Campaka, Cibogo and Cimaung Reservoirs with a total discharge of 361 l/sec. As the population grows, the clean water demand also increases, while the amount of clean water also decreases. Therefore to able to meet the water demand in the future, PDAM Purwakarta plans to increase the service to 90% by 2030, so based on the results of population projections and water demand projections the water demand will increase to 657 l/sec. An increased in capacity is carried out by constructing new water treatment plant (WTP) module at the Ubrug Water Treatment Plant PDAM Purwakarta which still has a large area of land, with the water source used is the Jatiluhur Reservoir. At present Ubrug Water Treatment Plant has two WTP modules with a total capacity of 160 l/sec, so to meet the water demand in 2030, it requires an additional capacity of 300 l/sec. Based on comparison of raw water quality with quality standards in the Minister of Health Regulation (Permenkes) 492 of 2010, the parameters that must be treated are E. coli 150 MPN/100 ml sample, organic matter 22 mg/l, color 20 TCU and turbidity 10 NTU. The selection of alternative water treatment configurations is done by considering the results of laboratory testing, interviews, and literature studies. The analysis results obtained are that processing using a slow sand filter is no longer possible to use, because based on the results of literature studies and interviews conducted to the Purwakarta PDAM it was found that the amount of nutrients in the Jatiluhur Reservoir water is high, causing algae growth which can clog the filter and cause frequent clogging occurs in the slow sand filter unit. To treat these parameters, the treatment unit configuration used consists of pre-chlorination, coagulation, flocculation, sedimentation, rapid sand filter, and disinfection. Pre-chlorination are needs as pre-treatment to treat high organic matter in raw water, so that it is expected to prevent the growth of algae in the main treatment unit, especially in the platte settler in the sedimentation unit. The process of coagulation and flocculation in raw water treatment is carried out to treat turbidity caused by colloids, turbidity levels in raw water are fluctuative depending on the weather, when the rainy season turbidity in raw water can reach more than 30 NTU and while in the dry season the turbidity is in range 5-10 NTU, so that it is necessary to do a jartest every time there is an increase and decrease in turbidity to get the right dose of coagulant. The coagulation and flocculation units are side by side with sedimentation units to precipitate the sludge produced. The rapid sand filter unit is placed after the sedimentation unit to filter out the rest of the floc that is not deposited by the sedimentation basin, this unit can also be used to reduce color. The final process of the treatment is disinfection or post-chlorination, which is to ensure that water that reaches the customer is free of pathogenic microorganisms. At the end of the treatment plant is planned to use a reservoir so that planning is done using daily maximum discharge. At the end of the treatment with the configuration units theoretically the results will be obtained E.coli 0 MPN/100 ml sample, organic matter 5.5 mg/l, turbidity 0.05 NTU, and 0.2 TCU color.