When we think of human excreta, the words “useless” and “smelly waste” often come to mind. However, this perception stems from a lack of awareness, leading to poor waste management and inadequate sanitation practices. Alarming statistics on low toilet coverage released by the ministry of water and environment reflect the pressing need for solutions. Fortunately, the National Water and Sewerage Corporation (NWSC) has stepped in to bridge the knowledge gap and revolutionize waste treatment. By introducing groundbreaking initiatives like the Nakivubo wastewater treatment plant, NWSC has turned sewage into a valuable resource, contributing to public health protection, environmental conservation, and economic benefits.
Sewage management has long been a challenge, with many individuals and institutions failing to construct proper waste disposal systems. During rainy seasons, drainage systems become inundated with sewage, posing serious health risks to the public. Fortunately, organizations like NWSC have emerged to tackle waterborne diseases resulting from poor sanitation and hygiene. Their innovative approach involves adding value to sewage by generating heat and electrical energy, paving the way for significant improvements in waste treatment.
A monumental achievement by NWSC, the Nakivubo wastewater treatment plant stands as the largest facility of its kind in East and Central Africa. Treating sewered waste from the bustling Kampala Metropolitan area, the plant processes an average of 17,7534m3 per day through four essential stages. The pre-treatment phase involves removing solid waste, grit, and grease to protect downstream equipment. Next, primary treatment utilizes sedimentation tanks to separate sludge, pre-treated waste, and scum. Biological treatment takes center stage with trickling filters breaking down organic matter into inorganic matter. Finally, secondary treatment employs sedimentation tanks to produce effluent that meets National Effluent discharge standards, returning it to the Nakivubo channel.
Ingeniously, NWSC takes waste treatment a step further by generating valuable energy. Primary and thickened sludge undergo anaerobic digestion, breaking down organic matter with the help of anaerobic bacteria. This process yields biogas composed of methane, carbon dioxide, and other gases. The purified biogas is then used to power Combined Heat and Power (CHP) units, generating both electrical and heat energy. Ms. Scovia Owomugisha, the plant manager, proudly reveals that the plant generates an average of 23,039kWh/month. Moreover, in the financial year 2021/22, the plant saved electricity costs worth 152,057,950 UGX, exemplifying the immense benefits of sustainable waste management.
NWSC recognizes the importance of collaboration to achieve a greener and healthier future. Eng Mahmood Lutaaya, the General Manager, highlights their partnership with Kampala Capital City Authority (KCCA) to ensure efficient waste management and recycling. Environmental education programs are undertaken to instill eco-friendly practices, such as tree planting and agro-forestry. Connecting more buildings to the sewer line aims to combat poor waste disposal in the city, promoting hygiene and sanitation. Additionally, NWSC’s collaboration with the Ministry of Health resulted in the construction of a sewage treatment plant in Kiruddu, curbing the spread of diseases caused by poor sanitation.
The paradigm-shift in sewage management led by NWSC demonstrates the remarkable potential of transforming a once troublesome issue into a wealth-generating opportunity. By embracing sustainable waste treatment practices, such as generating energy and producing fertilizers, NWSC has successfully protected public health, conserved the environment, and strengthened financial viability.
