Rosaria Chifari | ENT Foundation

An increase in the selective collection of the organic fraction of urban solid waste is expected in the coming years, but are there enough facilities to treat it in Spain?

The new directives on waste have imposed three important challenges for all Member States: limiting the proportion of municipal waste that can be sent to landfills to a maximum of 10% by 2035; the mandatory implementation of separate collection for bio-waste before December 31st, 2023; the limitation that from 2027 only the organic fraction that is separately collected counts for the calculation of the recycling rate. These challenges, added to the recycling target to be achieved by 2035 (65%), act as key drivers for introducing improvements in existing urban waste management systems.

In Spain, Autonomous Communities (ACs) have the responsibility of achieving the objectives set at state level since they are responsible for the collection and treatment of municipal waste.

The role of the ACs is relevant since, according to Spain’s National Waste Management Plan (PEMAR 2016-2022), to guarantee compliance with national objectives, the ACs need to meet at least those objectives within their territories: each AC has to meet the objectives independently.
At national level, in 2018, 22,265 Mt were generated, and the selective collection reached 17.7% of Municipal Solid Waste (MSW) generated, the remaining part being the residual fraction (RF) (79.3%) and bulky waste (3.0%). The four main fractions separately collected were paper and cardboard (27.1%), organic (25.6%), including biodegradable waste from kitchens and restaurants and vegetable fraction from parks and gardens, glass and glass containers (21.2 %) and mixed packaging (18.8%)[1].

The increase in selective collection is closely related to the ratio of separate collection of the organic fraction, given its relevance within the composition of MSW (in Spain it represents 42.72% of the total generated)[2]. Thanks to a series of measures implemented in Spain for biodegradable waste, its disposal in landfills has been progressively reduced and its selective collection has increased. In fact, the separate collection of biowaste in Spain in 2018 (1,006,000 t/year)1 more than doubled the tonnes collected in 2006 (400,000 t/year)1. The introduction of an increasing Catalan landfill and incineration tax and the mandatory introduction of separate bio-waste collection in all the municipalities of Catalonia since 2008 made an important contribution to this increase.

Selective collection is not carried out in a generalized way in the country. In fact, in 2018, 24%, 26% and 54% of the light packaging, paper and cardboard and glass fractions generated were collected at national level, respectively. For biowaste, the situation is even worse since only 12% of the organic fraction generated is separately collected. In the communities where a more generalized selective collection of organic matter is practiced (in Catalonia and Navarra), a maximum of 34% of the organic waste generated is separately selected. In 2018, in 6 ACs (Cantabria, Ceuta, Extremadura, La Rioja, Melilla and Murcia) the organic fraction of MSW (biodegradable waste from kitchens and restaurants) was not collected selectively while in 2 CAs (Castilla La Mancha, Castilla y León) biowaste collection had just started. When not selectively separated, biowaste is in most cases treated mixed with the residual fraction in Mechanical Biological Treatment (MBT) plants.

The recycling levels of MSW are different in each region, which shows the different MSW management strategies used at regional level[3]. Profound changes will have to take place in the urban solid waste management systems of most Spanish regions to achieve the objectives set at European level.
For many ACs, achieving these changes represents a great challenge. In addition to the need of having to implement the selective collection of organic matter on a mandatory basis, they also face having to treat a greater amount of organic fraction collected selectively and the fact that the tonnes of biostabilized produced from MBT plants of residual fraction can no longer be counted as “recycled material”. Hence the need to increase the capacity for organic recovery through the implementation of new infrastructures or the reconversion of existing MBT of RF in facilities that can receive and recover selectively collected biowaste. Without this technological adaptation, many MBT plants would be oversized and without the introduction of new biological treatment plants for selectively collected organic fraction, large quantities of organic fraction will have to be exported to plants located outside the generation area with negative consequences on transportation and environmental costs. Regional self-sufficiency in biowaste treatment capacity with the implementation of composting and anaerobic digestion plants can drastically reduce those costs.

The important investments destined to the realization of MBT plants have contributed to opening a gap between the number of plants of this type and those for the biological treatments for separately collected biowaste. Furthermore, the ACs, until now were not required to provide evidence regarding the final destination of the biostabilized, so that everything produced was counted as recycled material regardless of whether it is actually sent to recovery (i.e., R10[4]) or not.

Regarding waste management in 2018, the majority (53.4%) of the MSW generated in Spain was sent directly (15.9% without prior treatment) or indirectly (37.5% as rejection of other treatments) to landfills while 11.6% went to incinerators -with or without energy recovery. 14.8% of generated MSW was sent to composting or anaerobic digestion in MBTs, 2.3% to composting plants or anaerobic digestion of biowaste, 18.0% to recovery of materials (14.5% from separate collection and 3.5% from MBTs).

At national level there are 139 biological treatment plants (89 MBTs of RF and 50 plants for the biological treatment of bio-waste) that are not distributed homogeneously in the 17 ACs. 28 of the national bio-waste treatment plants are in Catalonia, where about 67% of the total biowaste selectively collected and sent to this type of treatment is treated at national level. On the other hand, most MBT facilities are in Andalusia, the Valencian Community, Castilla y León and Catalonia. The MBTs of these 4 regions, treat around 63% of the residual fraction generated at national level.

Considering that only 12% of the organic fraction of MSW generated at state level is separately collected and a significant increase in the selective collection of the organic fraction is foreseen, the plants for the biological treatment of biowaste existing at national level are not enough.

With the current configuration of the MSW management system, it is not foreseeable that Spain will be able to achieve the recycling targets established by the European Union. The ACs will have to focus on reducing the contributions of MSW to landfills by introducing prevention measures and increasing the amount of waste destined for recycling (in particular, the organic fraction), investing in optimizing the efficiency of the facilities in operation, introducing new infrastructures or reconverting gradually some of the most flexible MBTs.


[3] Sastre, S., Llopart, J. and Puig, I. (2018) ‘Mind the gap: A model for the EU recycling target applied to the Spanish regions’, Waste Management. Elsevier Ltd, 79, pp. 415–427. doi: 10.1016/j.wasman.2018.07.046.
[4] Soil treatment, producing a benefit or an ecological improvement to the agriculture.