The Viability of Selling Clean Treated Waste-water and Sludge from Gimboki Sewer Plant on Cost Recovery Basis

Abstract

In a bid to minimize the operational and maintenance costs associated with sewerage treatment plants, Gimboki Sewerage Treatment Plant invested heavily in cost reduction and recovery initiatives which include selling sludge and treated wastewater to downstream farmers for fertilizing and irrigation respectively. However, the viability of these initiatives at Gimboki is yet to be realized. The study evaluated the viability of selling clean treated waste-water and sludge from Gimboki Sewage Treatment Plant at a price based on cost recovery basis to farmers downstream. The objectives of the study were to; examine irrigation water needs by downstream farmers, estimate the effect of seasonality on irrigation water demand from existing water sources, ascertain the perceived usefulness of treated wastewater for irrigation purposes, determine the challenges influencing farmers’ decisions not to acquire treated wastewater from Gimboki Sewer Treatment plant and investigate the contribution of wastewater sales and sludge sales on revenue generation. The study was hinged on Economic theory. The study adopted the positivism research philosophy with a deductive research approach due to the need to make analysis and inferences based upon the sample data. The study employed an experimental research design. The target population was 150 farmers with downstream farms in Mutare which can be supplied treated wastewater at zero pumping cost using gradient system. Simple random sampling techniques was used to select 109 respondents. The data was gathered using self-administered questionnaires. The study used descriptive statistics in presenting the findings. Data were analysed using OLS regression. Independent samples t-tests and correlation analysis were also conducted to determine the relationship between the variables. The study findings revealed a significant monthly shortage of irrigation water for farmers downstream. The findings also revealed that seasonality has a significant impact on the demand of irrigation water. Treated wastewater from Gimboki was found to have a significant positive impact on irrigation as it provides crops with useful nutrients. Use of treated wastewater from Gimboki perceived to increase competitiveness in farming as it increases the agricultural yields due to its provision of sufficient nutrients needed by crops. Three critical challenges that strongly influence the farmers downstream not to buy wastewater from Gimboki were identified to be; contractual obligations with existing irrigation water suppliers, fear of soil and environmental destruction and fear of change. Selling treated wastewater and sludge to the farmers’ downstream sources revenue for wastewater treatment utility. The study recommended the production of clean treated wastewater which is directly proportional to demand at a cost-effective disposal. This will benefit the company both financially and environmentally and have a positive impact on the intended beneficiaries.