Economic evaluation of small desalination plants from brackish aquifers. Application to Campo de Cartagena (SE Spain)

The Campo de Cartagena (Eastern Spain) is one of Europe’s driest areas with a mean precipitation of around 300 mm. One of the main challengesin the region is to secure a reliable water supply in both quantity and quality terms, to provide a water supply and agricultural irrigation, while water desalination has become an extensively applied solution, and one of the most sustainable solutions to the water scarcity problem. As water availability is lacking and groundwater quality is poor, the agricultural sector in Campo de Cartagena has developed small private brackish groundwater desalination plants (15-20 m3/h) through already existing agricultural wells. Costs and benefits (C-B) for citrus cultivation (1 ha) in three such plants have been assessed. The results indicate that for the studied cases, current agricultural management is feasible and costs outweigh benefits, with a positive NPV and a cost/benefit ratio higher than 1. The internal rate of return is also positive and higher than 11%. The results evidence practical and theoretical implications as to how to increase water resources in areas where water is scarce by closing the loop, ensuring farmers’ profitability and encouraging private sector investments.Peer ReviewedPostprint (author's final draft

Social and private costs of water for irrigation: the small desalination plant in San Vicente del Raspeig, Spain

Among non-conventional water resources, desalination (from seawater or brackish aquifers) has emerged as a feasible option to deal with water shortages in arid or semi-arid areas. At the University of Alicante (UA, SE Spain) water availability is lacking and groundwater is poor. To ensure water availability, the UA built a small reverse osmose (RO desalination plant (45 m3/day) to water the green areas and an urban park on the campus. The costs of a small private desalination plant, landscape irrigation and the full cost were assessed. This assessment considered the benefits made by the green areas existing in an urban space and citizens' willingness to pay (WTP) for its preservation based in the contingent valuation method (CVM)Peer ReviewedPostprint (author's final draft

Costo de la desalobración de aguas subterráneas con pequeñas plantas desalobradoras (<2200 m3/(dia) y su uso en el campo de Cartagena

El Campo de Cartagena (SE peninsular), cuenca sedimentaria constituida por materiales Neógenos y Cuaternarios, se caracteriza por un intenso desarrollo agrícola. El sistema hidrogeológico multicapa está constituido por la presencia de niveles profundos confinados y un acuífero somero libre; el agua presenta diversos grados de salinidad de origen natural y antrópica. La demanda hídrica está cubierta por agua subterránea, trasvase Tajo-Segura, agua desalada (mar) y desalobrada (acuíferos). Las pequeñas plantas desalobradoras (= 2200 m3/día) procesan el agua por osmosis inversa (OI) y tienen una importante participación en la aportación de recursos hídricos, pero existe escasa información del coste del agua asociado. Debido al gran número de plantas desalobradoras existentes, sus características específicas, la calidad de agua desalobrada, profundidad de pozo/sondeo, producción (m3), el análisis del coste final del agua se ha realizado solo para una muestra específica. El coste medio del m3 de agua desalobrada para nueve plantas elegidas, con una producción comprendida entre 120 m3/día y 2200 m3/día, oscila entre 0.17-0.24 €/m3, y resulta competitivo para usos agrícolas, donde la demanda de agua para riego agrícola en la región alcanza el 87% de los recursos hídricos disponibles, y la superficie regable es en promedio de unas 190 mil hectáreas.Postprint (published version

Costo de la desalobración de aguas subterráneas con pequeñas plantas desalobradoras (<2200 m3/(dia) y su uso en el campo de Cartagena

El Campo de Cartagena (SE peninsular), cuenca sedimentaria constituida por materiales Neógenos y Cuaternarios, se caracteriza por un intenso desarrollo agrícola. El sistema hidrogeológico multicapa está constituido por la presencia de niveles profundos confinados y un acuífero somero libre; el agua presenta diversos grados de salinidad de origen natural y antrópica. La demanda hídrica está cubierta por agua subterránea, trasvase Tajo-Segura, agua desalada (mar) y desalobrada (acuíferos). Las pequeñas plantas desalobradoras (= 2200 m3/día) procesan el agua por osmosis inversa (OI) y tienen una importante participación en la aportación de recursos hídricos, pero existe escasa información del coste del agua asociado. Debido al gran número de plantas desalobradoras existentes, sus características específicas, la calidad de agua desalobrada, profundidad de pozo/sondeo, producción (m3), el análisis del coste final del agua se ha realizado solo para una muestra específica. El coste medio del m3 de agua desalobrada para nueve plantas elegidas, con una producción comprendida entre 120 m3/día y 2200 m3/día, oscila entre 0.17-0.24 €/m3, y resulta competitivo para usos agrícolas, donde la demanda de agua para riego agrícola en la región alcanza el 87% de los recursos hídricos disponibles, y la superficie regable es en promedio de unas 190 mil hectáreas

Social and private costs of water for irrigation: the small desalination plant in San Vicente del Raspeig, Spain

Among non-conventional water resources, desalination (from seawater or brackish aquifers) has emerged as a feasible option to deal with water shortages in arid or semi-arid areas. At the University of Alicante (UA, SE Spain) water availability is lacking and groundwater is poor. To ensure water availability, the UA built a small reverse osmose (RO desalination plant (45 m3/day) to water the green areas and an urban park on the campus. The costs of a small private desalination plant, landscape irrigation and the full cost were assessed. This assessment considered the benefits made by the green areas existing in an urban space and citizens' willingness to pay (WTP) for its preservation based in the contingent valuation method (CVM)Peer Reviewe

Economic evaluation of small desalination plants from brackish aquifers. Application to Campo de Cartagena (SE Spain)

The Campo de Cartagena (Eastern Spain) is one of Europe’s driest areas with a mean precipitation of around 300 mm. One of the main challengesin the region is to secure a reliable water supply in both quantity and quality terms, to provide a water supply and agricultural irrigation, while water desalination has become an extensively applied solution, and one of the most sustainable solutions to the water scarcity problem. As water availability is lacking and groundwater quality is poor, the agricultural sector in Campo de Cartagena has developed small private brackish groundwater desalination plants (15-20 m3/h) through already existing agricultural wells. Costs and benefits (C-B) for citrus cultivation (1 ha) in three such plants have been assessed. The results indicate that for the studied cases, current agricultural management is feasible and costs outweigh benefits, with a positive NPV and a cost/benefit ratio higher than 1. The internal rate of return is also positive and higher than 11%. The results evidence practical and theoretical implications as to how to increase water resources in areas where water is scarce by closing the loop, ensuring farmers’ profitability and encouraging private sector investments.Peer Reviewe

Agricultural irrigation of vine crops from desalinated and brackish groundwater under an economic perspective: a case study in Siggiewi, Malta

Maltese agriculture faces great challenges due to the severe scarcity of water. Sufficient water resources, in quantity and quality, are necessary to cover the demand in the production of wine grape, one of the most important crops in Maltese agriculture. But also, economic efficiency is essential in the grape cultivation. A Cost-Benefit Analysis (CBA) is defined for Maltese vineyards in the Siggiewi region, considering two irrigation scenarios, irrigation with groundwater or “do-nothing”, compared with the “use non-conventional waters” from mixing water from a small desalination plant and groundwater. For the alternative ‘mixing desalinated water with groundwater’ it is possible to improve water availability and quality for vine crops, while increasing economic benefits for farmer. The results indicate a profitable project from a minimum area of 1 ha, but final benefit is highly dependent on the irrigated surface extension according to water price. Desalination, compared with other type of non-conventional water is considered the best option in this assessment with a small reverse osmosis (RO) desalination plant (120 m3/day) for covering the irrigation needs.Peer Reviewe

Groundwater salinity process, mitigation measures and economic assessment: an example from an intensive agricultural area

To satisfy water demand in the arid climate area (SE Spain), small private desalination plants (more than 1000) of brackish groundwater are in operation. This process has led to an increase of groundwater salinity as a consequence of aquifers connection, uncontrolled subsurface injection of brines and pitfalls of the brines conveyor network. Measures being taken, including the economic efficiency of the small private desalination plants with regard to groundwater, and obtained results are presented.To satisfy water demand in the arid climate area (SE Spain), small private desalination plants (more than 1000) of brackish groundwater are in operation. This process has led to an increase of groundwater salinity as a consequence of aquifers connection, uncontrolled subsurface injection of brines and pitfalls of the brines conveyor network. Measures being taken, including the economic efficiency of the small private desalination plants with regard to groundwater, and obtained results are presented

Groundwater salinity process, mitigation measures and economic assessment: an example from an intensive agricultural area

To satisfy water demand in the arid climate area (SE Spain), small private desalination plants (more than 1000) of brackish groundwater are in operation. This process has led to an increase of groundwater salinity as a consequence of aquifers connection, uncontrolled subsurface injection of brines and pitfalls of the brines conveyor network. Measures being taken, including the economic efficiency of the small private desalination plants with regard to groundwater, and obtained results are presented.To satisfy water demand in the arid climate area (SE Spain), small private desalination plants (more than 1000) of brackish groundwater are in operation. This process has led to an increase of groundwater salinity as a consequence of aquifers connection, uncontrolled subsurface injection of brines and pitfalls of the brines conveyor network. Measures being taken, including the economic efficiency of the small private desalination plants with regard to groundwater, and obtained results are presented.Postprint (published version