Gerga, Egypt -- Crops grown on the Egyptian desert using treated wastewater are safe for human consumption and their production is economically viable, concluded engineers working on an experimental farm in Gerga, in the Sohag Governorate of Egypt.
Their final report, 'The Re-use of Treated Sewage Waste Water in Agriculture' contains recommendations for a successful country-wide establishment of wastewater irrigated farms, in support of Egypt's bit to tackle water scarcity and meet the growing demand for agricultural products. Since its launch in 2013, the pilot project has identified crops and soils suitable for wastewater irrigation and analyzed the environmental, social and economic impacts of this method.
In the last phase of the project, the engineers conducted a market research on town, province and country level to evaluate the economic viability of wastewater irrigation. Their results show that the total consumption of certain products suitable for wastewater farming exceeded domestic production by a large margin. To fill that gap, Egypt imports over 725 thousand tonnes of oriental beans and over 85 thousand tonnes of chick peas as well as lentils, maize and vegetable oils.
Combining data from a rural survey and national figures, the report also revealed a domestic deficit of thousands of tonnes of crops, such as sunflower, figs, pomegranates and hibiscus, suggesting that their production could find a permanent market in Egypt. The presence of several wholesale and retail markets also means the produce could find a ready outlet.
The growing need for water was the primary driving force behind the experiment, but using wastewater in farming has other benefits, such as preserving the natural sources of water, allowing harsh soil with no nutrients to be used, disposing of sewage effluent and reducing the end product cost.
Even if only used for producing fodder, motor oil, lubricants or seeds, wastewater irrigation can significantly reduce water stress, saving fresh water for growing crops that are eaten raw. Some sewage fed products, such as biofuels and trees, could also reduce demand for conventional heating sources.
The study recommends establishing small, compact treatment plants, to serve villages and limited residential communities. These would allow for setup of irrigating areas in their vicinity, saving the cost of transporting water networks to treatment sites and on to farm sites.
The farm conducted experiments on a range of agricultural crops, including lentils, beans, chick-peas, white figs, olive and pomegranates. Precautions, including dry air treatment, were put in place to ensure consumer-fitness of these products. The 2.5 acres farm was managed by the Egyptian Holding Company for Potable Water and Sanitation in Cairo and financed by the United Nations Environment Programme through the wastewater project of the Global Programme of Action for the Protection of Marine Environment from Land-based Activities (GPA) and the Italian Ministry of Environment, Land and Sea.
Other recommendations of the final report cover water treatment, soil and crop types, irrigation system types, institutional cooperation, upscaling of the project, involvement of private sector and civil society, and the use of usufruct, or common ownership system, rather than direct sales.
The experiment also drew on the lessons from previous experiments in Luxor, which showed promising results for cut flowers and animal feed such as sorghum.
The GPA is a global programme to protect the coastal and marine environment from land-based activities. It was adopted in Washington, D.C., US, in 1995.
It is an intergovernmental mechanism explicitly addressing the linkages between freshwater, coastal and marine environments. It recognizes that impacts of the land-based activities are transmitted through freshwater systems. Priorities for the GPA are marine litter, wastewater, and nutrient pollution. The GPA hosts three global partnerships to address these priorities.
UNEP is hosting the coordination unit of the GPA.