Background Olive oil production is an important agricultural sector in Europe. The annual production of olive fruits in the EU is more than 12 million tonnes, giving 2.9 million tonnes of olive oil, from approximately 12 000 oil mills. Wastes originating from this activity are olive mill solid wastes (OMSWs) and olive mill wastewaters (OMWWs). The latter can pose serious problems through its potential pollution charge of more than 200 g/l COD. The most common system for OMWW management adopted in the Mediterranean countries is the direct disposal to soil or in evaporation ponds. According to the International Olive Council, Europe produces annually 10 million tonnes of pomace (pulp) and vegetation wastewater from the processing of olive oil. Problems associated with this waste stream include difficulties of disposing of environmentally-hazardous organic pollutants and also challenges involved in encouraging sustainable management of the pulp production processes, usually by SME oil mills. Objectives Building on the results of a previous LIFE project (LIFE00 ENV/IT/000223 TIRSAV), the TIRSAV+ project aimed to demonstrate the cost-effectiveness of an innovative technology at oil-mill level through the planning and construction of a centralised recycling plant. The unit was also planned to be able to recycle other organic wastes to produce organic fertilisers that are easy to use and acceptable for farmers. Finally, the project sought to promote the harmonisation of legislation at European level regarding the oil-mill wastes. Results Outcomes from the TIRSAV+ project include developing and testing innovative treatment processes that provide effective solutions for converting oil mill waste into useful agricultural resources (compost and innovative fertilisers). Project findings highlight new options for treating (by the same process) both OMWW and OMSW. This process is much more effective than other solutions that address the issue only in a partial way, retrieving only the virgin olive residues or only the vegetable water. In addition, the process is applicable to the various systems of olive oil extraction (i.e. pressure systems, continuous cycle two stage, continuous cycle in three phases). Project actions focused on a composting procedure tackling both OMWW and OMSW via a three-phase extraction system. Wet OMSW was treated by a two-phase extraction technique within the same processing system. The combined effect results in high quality compost and flexible maturation systems allows the technology to be tailored to different needs of different oil mills. Two main systems were demonstrated. The PCS (Passive Composting Simplified) approach consists of a pre-treatment step, followed by a slow maturation and a further treatment. The ACC (Active Composting Composite) approach involves a pre-treatment step, followed by active ripening and refining phases. The compost produced by both methods is in accordance with the criteria of traceability, environmental sustainability, and agronomic efficiency. The by-products satisfy high quality requirements, allowing their use even in organic vegetable production, ‘fourth range’ production and floriculture production. Project operations led to some 2000 tonnes of oil-mill wastes being recycled. This corresponds to a saving of 615 500 Kg CO2eq. Pollution risks to surface and groundwater were also significantly reduced by effective treatment of some 1000 tonnes of OMWW by the plant. At full regime (within the limits of the present authorisations), the plant could achieve reductions of 2 940 500 Kg CO2eq each year, and a disposal of some 4000 tonnes a year of OMWW. If translated to the EU scale, the TIRSAV+ process system could produce about 3.6 million tonnes per year of high quality compost for use in agricultural soils. Greater efficiency in terms of recycling of organic matter can also be achieved from the production process. 100% of the organic waste produced by the extraction process of the olive oil (olive pomace, vegetation water, leaves, branches, tank washings) is recycled. Project results are thus in line with the strategies of the European Directive on waste (Directive 2008/98/EC), which provides for the application of the waste hierarchy (prevention, preparation for re-use, recycling, recovery and disposal) and the introduction of quality standards for compost. New processes demonstrated by the project upgraded previous mixing systems, as well as plant for separating olive stone. The processes of loading and unloading from a processing step to another, and the automatic control system (PLC), have also been upgraded, improved and implemented. The whole process was conceived as a modular flexible system according to the quality and quantity of materials to be treated. A unique system of maturation of compost in small containers (Bins and Big bags) has also been developed. Lessons learned from the LIFE project include clarification that the start-up phase for such a project can be longer than foreseen. In the three years of experimental and demonstrative operations the plant produced less than its inherent capacity and the sale of the products proved to be more difficult than expected. The plant had to operate at one third of the limits imposed by the regional authority – and at 1/18 of its current potential. This indicates good job creation opportunities from mainstreaming the project technologies if these difficulties can be overcome. Nonetheless, from a qualitative environmental standpoint, the results have shown that the adopted design and technology choices does help solve OMWW problems altogether. The broad range of environmental benefits from this treatment remains highly relevant for many olive regions, and particularly those located in or near to protected areas. Efforts to produce specially prepared composts succeeded. These can be designed to respond to specific cultivation requirements, such as the production in open field, protected crops, biological or out of the ground cultures. The project’s four types of compost, currently in production as soil conditioners (GREEN-LIFE, NATURLIFE, ECO-LIFE, BIO-LIFE), showed structural, chemical, physical and microbiological characteristics different from each other. In addition, new perspectives were opened in terms of the characterisation of compost quality, to better classify the soil conditioners produced by the different operators and define their best use. Whilst sales of the olive-stone compost did increase steadily, the quantity of pomaces delivered to the plant by nearby oil-mill owners was still too low to ensure the financial viability and sustainability of the plant. Commercialisation goals therefore remained a challenge for the beneficiary and a five year AfterLIFE commitment will see continued work to reinforce the treatment plant’s long-term sustainability. This includes aspirations to use the ERDF as an aid for further developing the commercial opportunities from treated oil mill compost. In addition, a legal proposal was made for a revision of the legislation on oil waste treatment, which points at adopting stricter rules on the handling of these by-products, on account of their inherent hazardousness for human health, for the soil and the surface/groundwater. The two projects have made steps to present the proposal to the Italian Ministries of Environment and Agriculture and to the European Parliament as well. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).