PROTECTED HORTICULTURE AND ENVIRONMENT. AN INTEGRAL DECISION MODEL FOR GREENHOUSE WASTE MANAGEMENT IN SOUTHEASTERN SPAIN

Over 380000 tons of vegetable waste is produced annually in the “Campo de Dalías” zone(Almería, Spain), deriving from the diverse existing crops grown under plastic cover. Landfillscontaining this vegetable waste are a potential breeding ground for diseases and pests, they can alsobe the subject of uncontrolled burning, cause a riverbed blockage and, at the same time, they are anunsightly aspect of the landscape. The only way to prevent or minimize this problem is to adopt acomprehensive and environmentally sensitive waste management program.The utilization of the Contingent Valuation Method (CVM) has allowed the monetarization ofthe total environmental benefit of the projects undertaken, composting plant or in an energy recyclingprocess, to the tune of 4082777 € and 4794566 €, respectively. Likewise, a Geographical InformationSystem (GIS) has been used to locate an optimal zone for a composting plant. The solution obtainedminimizes the transportation cost of organic waste. It represents 40% of the total cost at currentmarket price. The subsequent integration of the results obtained with the previous methods in a cost-benefitanalysis showed when a decision on possible public action needed to be taken that the bestoption would be a composting project with a 63.58 million € Net Present Value (NPV), including theinternalization in economic terms of the environmental benefit of recycling organic residue. If thisbenefit is not internalized, the project NPV would be negative.