The Gipuzkoa Waste Consortium (GHK) has awarded the concession contract to build and exploit the biomethanization and valorization of slag plants for 20 years to group of companies made up of Biergrim S. L, Ecofert Sansoain S.L, Fomento de Construcciones y Contratas SA, Garrai SA, Urbycolan S.L, and Valoración y Tratamiento Residuos Urbanos S.A. (VYTRUSA)