The Study of Impact of Tofu Industrial Waste Treatment Plant on Value of Chemical Oxygen Demand Level in Residents Well of Central Lamper Village, Semarang-Indonesia

Background and Objective: The existence of a tofu waste treatment plant in residential areas and reports from the public about the unpleasant odor in several wells made residents worried about the impact of the intrusion of tofu waste treatment plant waste. This study aims to assess the impact of possible intrusion of waste from tofu waste treatment plants into residents' wells.  Methods: This type of research is descriptive with a survey method. Samples from the research site were analyzed in the laboratory by the titration method based on the value of chemical oxygen demand, compared with Government Regulation of the Republic of Indonesia No. 82 Th. 2001 concerning water quality management and water pollution control. Results: The results of the measurement of the chemical oxygen demand value of the Bajak river were 51.8 mg/L (starting point) and 238 mg/L (end point). The value of chemical oxygen demand in resident wells is as follows: resident well 1 of 12.2 mg/L, resident well 2 of 9.12 mg/L, resident well 3 of 3.05 mg/L, residential well 4 mg/L of 33.05 mg/L. L, resident well 5 is 3.05 mg/L, resident well 6 is 15.2 mg/L, resident well 7 is 27.4 mg/L and resident well 8 is 3.05 mg/L. Conclusion: The value of chemical oxygen demand in the Bajak river exceeds the quality standard, while the value of chemical oxygen demand in resident wells shows that the farther from the tofu waste treatment plant, the smaller the concentration value of chemical oxygen demand.