The Guardia Civil are investigating the sudden appearance of various illegal sites where building rubble has been dumped. It consists mainly of plastic and paper used to wrap building materials and which cannot be reused. The appearance of these illegal tips coincides with the opening of provisional dumping stations for builders' rubble in Palma, Calvia, Llucmajor, Manacor, Artà and Inca. These stations were opened in an effort to regulate and control rubble, following disputes after certain quarries used by builders were closed. There is a charge for using these new stations, and the illegal tips are seen as an effort to avoid these payments. The procedure is to excavate a hole to deposit the rubble and then cover it up. Several such tips have been discovered in the municipality of Marratxi, but others have been found elsewhere in the island. Once the contract for managing builders rubble is awarded, the transfer stations will become part of a global system, with two treatment plants for previously selected material. These two plants are already functioning, one in Ses Veles close to Son Reus and the other in Corral Serra in Santa Margalida. This system is designed to prevent uncontrolled dumping of rubble, and it puts the emphasis on selection and separation into rubble which can be used and that which cannot. The construction trade generates 800'000 tons of rubble a year and 150'000 tons of this cannot be reused. The amount of regular urban rubbish generated in the first six months of the year is 1.3 per cent more than last year.