Due to population growth and increasing water usage, various regions worldwide become water stressed. Converting wastewater into potable and/or process water can play a crucial role in closing the gap between water demand and supply. In contrast to rainwater, wastewater is weather-independent, which leads to fewer fluctuations in the water supply. Moreover, water should never be treated as a waste product but reused as a resource in a circular way. Upgrading wastewater to potable water with low environmental impact is the focus of this integrated technological solution.

Kericho in Kenya is located 250km NW of Nairobi, not far from Lake Victoria. The local WasteWater Treatment Plant (WWTP) treats the domestic wastewater of part of the 150,000 inhabitants. It consists of clarifiers, trickling filters and maturation ponds. Currently, the treated wastewater is discharged into the river. To make the region more climate resilient and guarantee water supply at drinking water standards in all seasons, a treatment sequence will be designed, built and monitored.

Ultrafiltration (UF) is a proven technology that separates pollutants and pathogens from water by means of membranes. The pores of these membranes are sensitive to clogging by biofouling and solids which impacts the performance of the UF and results in frequent/expensive maintenance. This problem is solved by placing a nature-based pretreatment that removes organic matter, nutrients and solids. Based on available data, the an aerated constructed wetland (ACW) in Kericho will treat a flow of 990m³/d on an estimated surface area of 1,400m². A UF membrane filtration unit will be used to further upgrade the treated waste water to process water or even drinking water quality.

This project covers the design, and construction phase of the planned installation, monitoring of the water quality after start-up, training of the operators, and capacity building for scientists from the nearby university. Funding sources are G-STIC and the Kericho County Government.