Masengere Isaac, Grace2026-06-172026-06-172026Masengere, I.G(2026), Design and Construction of a Water Treatment System,(Project Research Report), Busitema Universityhttps://bdears.busitema.ac.ug/handle/123456789/6098Undergraduate Research ReportAccess to clean, safe, and readily available drinking water is a fundamental pillar of public health and sustainable development worldwide. The borehole supplying Login Hostel in Syaule, Busia District, has severely hard water (320 mg/L as CaCO3), causing health and operational problems for students. To solve this, we designed and built a solar-powered electrocoagulation water softening system. The system meets a maximum daily demand of 3.9 m3/d for 30 residents. Electrocoagulation was chosen because it scored highest (126 points) in a technology analysis, and aluminum was selected for both electrodes with a score of 135 points. The design features a 7-ring helical coil creating 6 electrochemical cells inside a 3.5-inch polyvinyl chloride casing. It includes a three-stage downstream filter: a polypropylene sediment filter, a granular activated carbon buffer, and a compressed carbon block. Power comes from a 12.8 V, 120 Ah LiFePO4 battery, charged by a 300 W to 350 W monocrystalline solar panel and regulated by a 30 A Maximum Power Point Tracking charge controller. Testing at 9 V, 12 V, and 24 V proved that 12 V works best. At 12 V, the system removed 62% of the water hardness while using only 0.81 kWh/m3 of electricity. After 60 minutes of continuous flow, the final hardness dropped to a safe 125.3 mg/L. A 24-hour test showed the battery stayed safely above a 50% charge level throughout operation. Financially, the system costs 1,200,000 Ugandan Shillings to build. Over five years, it produces a Net Present Value of 11,330,586 Ugandan Shillings, a payback period of 5.4 months, and a profitability index of 7.30.enThesis