RISK ANALYSIS OF Cr AND Cu HEAVY METALS IN THE CIMANUK WATERSHED

Abstract

Background: The Cimanuk River is one of the rivers in the city of Garut. Cimanuk originates in the Mandalagiri Mountains in Garut Regency at an altitude of about 1700 meters above sea level (masl), flows northeast for 180 km, and empties into the Java Sea in Indramayu Regency. Residents along the Cimanuk stream use this river for agricultural and fisheries resources, both traditionally by fishing and netting; additionally, the Cimanuk river has the potential to become a tourist attraction for rafting.The name Cimanuk River comes from a story about a local who went hunting for manuk (birds) and drowned in the Cimanuk River's headwaters.The location of the suction mud is on Mount Mandalagiri, Cikandang Village, Cikajang District, Garut Regency. Because he drowned while hunting for manuk (birds), the river that flows from the quicksand was then named Cimanuk. The headwaters of the Cimanuk River are located on Mount Mandalagiri, in Cikandang Village, Cikajang District. The height is about 1,813 meters above sea level, and it is about 22 km from the capital city of Garut regency to the south. This river flows from Mount Mandalagiri in Garut Regency and empties into the Java Sea on the north coast. This river crosses the districts of Garut, Sumedang, Majalengka, Indramayu, and Cirebon and is the second longest river in West Java. The Cimanuk River is one of the main pillars of water resources in West Java. This river is capable of providing 2.2 billion m3 of water per year. But unfortunately, the Ministry of Environment and Forestry also mentions that the Cimanuk Watershed is the most critical watershed. Methods: Water quality monitoring data for the Cimanuk river in March, June, and October 2021 is sourced from DLHK Province, West Java, 2021, which is then calculated and analyzed using the formula Results: The results showed that from 5 sampling points, the average concentration of the heavy metal Cr was 0.005 mg/L, and the average concentration of the heavy metal Cu was 0.016 mg/L. The intake dose for March 2021 for the heavy metal Cr is at points 1–5 with an intake value of 0.0085 mg/kg/day, and the intake dose for Cu is at points 1–5 with an intake value of 1.559 mg/kg/day. The intake dose for June 2021 for the heavy metal Cr is at point 1 with an intake value of 0.027287671 mg/kg/day, at point 2–5 the intake value is 0.008527397 mg/kg/day, and the Cu intake dose is at point 1–5 with an intake value of 1.559 mg/kg/day. The intake dose for the heavy metal Cr in October 2021 is at point 1 with an intake value of 0.027287671 mg/kg/day, at point 2–5 the intake value is 0.008527397 mg/kg/day, and the Cu intake dose is at point 1–5 with an intake value of 1.559 mg/kg/day. The results of this study indicate that the risk of Cr heavy metal contamination at points 1–5 is 2.833333333. Meanwhile, the risk of Cu heavy metal contamination is 38.975 at points 1-5. Conclusion: Based on the data above, the risk value of the two metals Cu and Cr has a value of 1, so the value of the Cimanuk River watershed is at risk