Effect of Industrial Wastes on River Water Quality: A Case Study of Rwamagana Industrial Park on Rwamurinzi and Kiruhura Rivers, Eastern Province, Rwanda
Abstract
Freshwater resources face increasing global threats from overuse, pollution and industrial expansion, with industrial wastewater introducing toxic pollutants that jeopardise human health and sustainable development. In Rwanda, rising industrialisation, particularly around industrial parks, has heightened risks to rivers such as Rwamurinzi and Kiruhura. This study assessed the impact of wastewater discharged from the Rwamagana Industrial Park on the quality of these rivers in Eastern Rwanda. Between January and March 2025, both wastewater effluents and river water samples were systematically collected from upstream and downstream sections. Samples were analysed for physico-chemical parameters, including pH, dissolved oxygen and electrical conductivity, as well as heavy metals—lead (Pb), cadmium (Cd), and chromium (Cr). Findings revealed that concentrations of Pb, Cd, and Cr in both wastewater and river water exceeded Rwanda Standards Board limits, while pH and electrical conductivity largely remained within acceptable ranges. The Kiruhura River showed notably higher heavy metal concentrations, closely resembling those in the industrial wastewater and significantly higher than levels in the Rwamurinzi River. Statistical analysis demonstrated a strong correlation between wastewater composition and river water quality, confirming industrial discharges as a primary contamination source. The results highlight the urgent need for improved wastewater treatment systems and stricter regulatory enforcement in industrial parks. While this study focused on water samples and three metals, future research should expand to include sediment analysis and a wider range of pollutants to fully capture the environmental impacts of industrial activities.
Downloads
References
Chowdhary, P., Bharagava, R. N., Kumar, S. & Yadav, A. (2020). Role of industries in water scarcity and its adverse effects on environment and human health. In environmental concerns and sustainable development (pp. 235-256). Springer. http://dx.doi.org/10.1007/978-981-13-5889-0_12
Clark, J., & Thompson, K. (2023). Industrial waste treatment: Approaches and environmental impacts. Environmental Science & Technology, 57(6), 981-995.
Das, G. K. (2024). Water quality determinants of Mathabhanga, Churni and Jalangi rivers. In River Systems of West Bengal (pp. 129–140). Springer. https://doi.org/10.1007/978-3-031-53480-5_9
Dubey, D. K., Agarwal, S., Yadav, M. P., Goswami, A., & Ravat, A. (2024). The study of the effects of improper hazardous waste disposal on ecosystems. New Delhi: ABC Environmental Research Publications.
Ediagbonya, T. F., Uche I. J., Esi, O.E and Akinrefon, D.O. ( 2023b). Evaluation of Polychlorited Biphenyls (PCBs) in Sediment from Surface Waters in Igodan, Okunmon, Lebi, Idepe and OAUSTECH in Okitipupa Ondo State. J, Appl. Sci Environ, Manage 27 (9):2041- 2050
Ediagbonya, T. F., Uche I. J., Esi, O.E and Afolabi, O.J. ( 2023a). Determination of Polychlorited Biphenyls (PCBs) in Surface Water in Ondo State. Coast J.Sch.Sci 5(1):580- 863
Ellen MacArthur Foundation. (2013). Towards the Circular Economy: Economic and Business Rationale for an Accelerated Transition. Retrieved from https://www.ellenmacarthurfoundation.org/publications
ESRI. (2020). ArcGIS Desktop: Release 10.8 [Computer software]. Environmental Systems Research Institute.
FAO. (2019). Water quality for agriculture (FAO Irrigation and Drainage Paper No. 29, Rev. 1). Food and Agriculture Organization of the United Nations.
Fatta-Kassinos, D., Vasquez, M. I., & Vasquez, M. I. (2024). Wastewater Reuse and Current Challenges. Springer
Garcia, M., & Martin, L. (2020). The role of waste disposal in sustainable industrial operations. Journal of Environmental Management, 47(3), 478-490.
Geissdoerfer, M., Savaget, P., Bocken, N. M., & Hultink, E. J. (2017). "The Circular Economy–A new sustainability paradigm?" Journal of Cleaner Production, 143, 757-768. https://doi.org/10.xxxx/yyyy
Ghisellini, P., Cialani, C., & Ulgiati, S. (2016). "A review on circular economy: The expected transition to a balanced interplay of environmental and economic systems." Journal of Cleaner Production, 114, 11-32. https://doi.org/10.xxxx/yyyy
Government of Rwanda. (2018). Law N° 48/2018 of 13/08/2018 on Environment. Kigali, Rwanda: Government of Rwanda.
Harris, R. (2021). Recycling and reuse in industrial waste management. Waste Management Review, 16(4), 128-134.
IBM Corp. (2022). IBM SPSS Statistics for Windows, Version 28.0 [Computer software]. IBM Corporation.
Iyama, W. A., Nnadi, O. C., Ubong, I., Timothy, M. N., Dollah, C. O., Gbode, Y. L., Egbunefu, C. O., Emejuru, W. S., Nimame, P., & Onuegbu, W. C. (2024). Assessing the impact of petrol service stations on selected physico-chemical water quality parameters within Port Harcourt Metropolis, Nigeria. Journal of Geoscience and Environment Protection, 12(10), 1-15. https://doi.org/10.4236/oalib.1101593
Kadir, G. M., Alemayehu, H., & Dessalegn, D. (2023). Surface water pollution source identification and quantification: Literature review. American Journal of Water Science and Engineering, 9(3), 50–57. DOI: 10.11648/j.ajwse.20230903.11.
Li Lin, H. Y. (2022). Effects of water pollution on human health and disease heterogeneity: A review. Frontiers in Environmental Science. https://www.frontiersin.org/articles/10.3389/fenvs.2022.880246/full
Mugabo, J. K. (2022). "The need for stricter industrial wastewater regulations in Rwanda: A review." Environmental Policy and Governance, 32(1), 25-31. https://doi.org/10.xxxx/epg.2022.032.
REMA (2020). Guidelines for water quality management in Rwanda. Kigali, Rwanda. https://www.rema.gov.rw/fileadmin/user_upload/Water_Quality_Management_Guidelines_Final__Jan._2021_.pdf
Rutanga, J. P. (2014). Assessment of microbiological and physicochemical parameters of ground water: A case study of Gikondo industrial park, Kigali, Rwanda. Ethiopian Journal of Environmental Studies and Management, 7(2). https://www.ajol.info/index.php/ejesm/article/view/101918
Rwanda Development Board. (2024). Rwamagana Industrial Park development update. https://rdb.rw/rwamagana-industrial-park-update
Rwanda Standards Board (RSB). (2018). Potable water — Specification. Rwanda Standards Board.
Sabiiti, D. (2021, October 19). Quality of Nyabarongo Water Deteriorating – Research. KT Press. Retrieved from ktpress.rw
Sawyer, C. N., McCarty, P. L., & Parkin, G. F. (2023). Chemistry for Environmental Engineering and Science (5th ed.). McGraw-Hill.
Sharma, N. et al. (2021). "Chemical Composition of Industrial Effluents and Their Impact on Water Quality." Hydrology and Water Pollution, 21(3), 45-60.
Sharma, R., & Gupta, S. (2022). Sustainable waste disposal practices. Global Environmental Studies, 19(6), 332-348.
Shrestha, S., & Kazama, F. (2007). Assessment of surface water quality using multivariate statistical techniques: A case study of the Fuji River basin, Japan. Environmental Modelling & Software, 22(4), 464–475. https://doi.org/10.1016/j.envsoft.2006.02.001
Silva, T., Mendes, F., & Carvalho, R. (2022). Industrial Effluents and Water Quality Degradation: A Case Study of São Francisco River. Environmental Monitoring and Assessment, 74(2), 99-110.
Singh, R., Kumar, A., & Sharma, P. (2018). Liquid Industrial Waste Treatment and Recycling. Journal of Environmental Engineering, 12(4), 356-370.
Sinha, R., Kumar, S., & Sharma, P. (2018). Impact of industrial effluents on water quality and aquatic life in the Ganges River, India. Environmental Pollution, 234(1), 45-57. https://doi.org/10.1016/j.envpol.2017.11.062
Smith, J. B. (2020). Challenges in environmental regulation: A global perspective. Environmental Science Journal, 34(3), 200–210.
Tchounwou, P. et al. (2019). "Toxic Effects of Heavy Metals on Human Health." Environmental Toxicology, 14(2), 112-130.
The Guardian. (2025, February 5). East Anglian farms breach environment regulations 700 times in seven years. The Guardian. https://www.theguardian.com/environment/2025/feb/05/east-anglian-farms-breach-environment-regulations-700-times-in-seven-years?utm_source=chatgpt.com
Thompson, A., & Williams, D. (2023). Eutrophication and its mitigation in river systems. Aquatic Ecology Journal, 60(1), 45-59.
Twagiramungu, F., & Mugabo, J. (2019). Industrial pollution and water quality in the Gikondo Wetland, Kigali, Rwanda. East African Journal of Science and Technology, 9(1), 78–92.
[Available through Rwanda Environment Management Authority (REMA) or academic institutional libraries.]
UNEP (2016). A Snapshot of the World's Water Quality: Towards a Global Assessment. United Nations Environment Programme.
UNESCO (2021). UN World Water Development Report. Paris: UNESCO Publishing.
Uwizeyimana, P., & Nsengimana, T. (2021). The role of local communities in managing environmental pollution in Rwamagana District. Rwanda Environmental Journal, 2(3), 88–99.
Vymazal, J. (2010). Constructed wetlands for wastewater treatment: Five decades of experience. Environmental Science & Technology, 44(22), 8489-8497. https://doi.org/10.1021/es101403q
WHO (2022). Guidelines for drinking-water quality, 4th Edition. World Health Organization.
World Bank. (2018). Environmental governance in developing countries: Case studies and lessons from industrial waste management. Washington, DC: World Bank.
Wu, Y., Zhang, M., Zhang, J., & Wang, X. (2022). Effects of temperature shock on the survival of different life stages of large yellow croaker (Larimichthys crocea) by simulated power plant cooling water. Frontiers in Marine Science, 9, 1037137. https://doi.org/10.3389/fmars.2022.1037137
Zhang, J., Zhang, Z., Wang, J., Liu, W., Li, X., & Guo, H (2023). River water pollution: Causes, impacts, and management strategies. Global Environmental Studies, 39(5), 202-215.
Copyright (c) 2025 Jean Baptiste Havugimana, Thompson Faraday Ediagbonya, Christopher Mupenzi

This work is licensed under a Creative Commons Attribution 4.0 International License.