For many developing countries facing water scarcity, wastewater is the only reliable source of water available for agricultural purposes. To date about 10 per cent of the world’s crop production relies on wastewater irrigation. Ideally wastewater should be used for agricultural purposes after being treated, but the reality is far from that. Instead untreated wastewater irrigation has become a source of contamination, affecting crops and also the safety of groundwater and hence public health. Action must be taken to ensure the safe use of wastewater, not only by raising awareness but also making appropriate tools available.
In the capacity development workshop “Sustainable Management Options for Wastewater and Sludge” from 15–17 March in Mexico, UNU-FLORES joined forces with the Environmental Trust Fund of the State of Hidalgo (FIAVHI) to find sustainable and long-lasting solutions to these issues in the region.
Mexico’s Mezquital Valley is one of the largest and oldest areas practising wastewater use (on over 90,000 ha for over 100 years). Wastewater irrigation has given farmers in this semi-arid region not only a solution for water scarcity but also a way to increase their crop yield. However, it has also caused many environmental, sanitary, and social issues.
National and international experts from Dominican Republic, Germany, and Guatemala gathered at Tepeji del Rio de Ocampo in Hidalgo, Mexico to discuss the safe use of wastewater in agriculture (SUWA) in the Mezquital Valley. The eco-technological processes for water sanitation, as well as health and economic aspects were also examined at the workshop. UNU-FLORES promoted an integrated approach to manage the nexus between water, soil, and waste to improve the sustainable use of environmental resources.
As part of the workshop, FIAVHI organised a field trip to El Caracol, Tepeji and Huaska. It was demonstrated that the use of treated wastewater lowers the rate of health infections among the population and that alternative uses of treated water are possible as well as a source of income.
Workshop participants welcomed the concepts presented – particularly on sludge management and the Nexus Approach – and found them especially relevant for the sustainable management of the Valley. Among the recurring concerns during the workshop were the consequences for health in the use of untreated wastewater in agriculture as well as the risk of profit loss from nitrogen reduction in treated wastewater.
For the questions that remained at the end of the workshop, future collaborations for scientific research and capacity development have been planned with FIAVHI, the major of the Tepeji Municipality, and the Congress of the State of Hidalgo. Research areas will focus on the safe use of wastewater in agriculture, bioremediation of polluted surface water by wastewater, and the assessment of best operational plants to reach a safe equilibrium between nitrogen provisioning and pollution reduction in treated wastewater. Best treatment technologies and agricultural practices to reach the best nitrogen content/safe water ratio will also be explored.
This workshop has laid the foundation for a long-lasting and mutually beneficial partnership between UNU-FLORES and FIAVHI. Future capacity development aiming at the promotion of SUWA in the Mezquital Valley will be closely organised by both parties.
To view more photos from the workshop, see the slideshow here.