Directive 1999/31 applies only to waste that is disposed of, not to waste that is to be recovered, as Article 3(1) of the directive provides that it applies to all landfills, which are defined in Article 2(g) of the directive as waste disposal sites for the deposit of waste onto or into land. It follows that waste other than extractive waste may fall within the scope of Directive 1999/31 only if the waste is deposited in landfills for disposal, not if it is to be recovered. That is the correct interpretation of the second indent of Article 3(2) of the directive, which excludes from its scope the use in landfills of inert waste which is suitable in redevelopment/restoration and filling-in work, or for construction purposes.

Article 10(2) of Directive 2006/21 on the management of waste from extractive industries must be interpreted as not having the effect of making an operation entailing the backfilling of a quarry using waste other than extractive waste subject to the requirements of Directive 1999/31 on the landfill of waste, where that operation amounts to a recovery of waste, which is a matter to be determined by the national court.

Since Directive 1999/31 on the landfill of waste does not define the term ‘recovery’, reference must be made to the definition of that term as set out in Article 3(15) of Directive 2008/98 on waste. However, Article 3(15) of Directive 2008/98 defines, inter alia, the recovery of waste as an operation the principal result of which is that the waste in question serves a useful purpose by replacing other materials which would otherwise have been used to fulfil a particular function. It follows that the main objective of the recovery operation must be the conservation of natural resources. Conversely, if the conservation of natural resources constitutes only a secondary effect of an operation the principal objective of which is the disposal of waste, this cannot affect the classification of that operation as a disposal operation.

That being said, it must be possible to classify any waste treatment operation as either a disposal or a recovery, and, as is apparent from Article 3(19) of Directive 2008/98, a single operation may not be classified at the same time as both a disposal and a recovery. Consequently, where, having regard solely to the wording of the operations in question, a waste treatment operation cannot be brought within one of the operations or categories of operations referred to in Annex I or II to the directive, it must be classified on a case-by-case basis in the light of the objectives of the directive. In that respect, with regard to an operation entailing the backfilling of a quarry using waste other than extractive waste, it is a matter for the national court, having regard to all the relevant factors of the case, and taking into consideration the objective of protecting the environment pursued by Directive 2008/98, to determine whether the main purpose of such an operation is to recover waste other than extractive waste intended to be used during this backfilling operation. This may be the case if, on the one hand, it is established that the backfilling of the quarry in question would have taken place even if such waste had not been available and, accordingly, other materials would have had to be used. On the other hand, the backfilling of the quarry at issue may not be regarded as a recovery operation unless, in the light of the most recent state of scientific and technical knowledge, the waste used is suitable for that purpose.

(see paras 36, 37, 39, 41-43, 45)