Bizkaiko Foru Aldundia - Diputación Foral de Bizkaia

The European Directive relating to the Dumping of Waste (April 29 1999) defines, among other things, the concepts of "treatment" and "leachate":

• a) Treatment: These are physical, heat, chemical or biological processes, including separation, that change the characteristics of the waste in order to reduce their volume or hazardousness, facilitate handling or increase their value.
• b) Leachate: This is any liquid that penetrates through the waste deposited and is emitted or contained in a landfill. This is a highly contaminating agent that derives from the dumping of waste in landfills.
  

With regard to the treatment of leachates, the European Directive establishes that the appropriate measures will be taken with respect to the characteristics of the landfill and to the meteorological conditions, in order to:

• Control the rain water that penetrates the landfill basin.
• Prevent surface or underground water from penetrating into the waste dumped in the landfill.
• Collect contaminated water and leachates.
• Treat the contaminated water and leachates collected in the landfill so that they comply with the regulations required for their dumping.

The Stripping Plant of the Municipal Solid Waste landfill in Igorre reduces the amount of ammonia in the leachate in order to reach concentrations of under 300 mg/litre, in accordance with the requirements of the regulations controlling the dumping of water into the general network of collectors of the Water Consortium of Bilbao-Bizkaia.

Once treated, the leachate will be recovered in the Bedia Sewage Treatment Plant, together with the urban and industrial waste water of the Middle and Lower Arratia Valley.

This facility, inaugurated on April 26 1999, complies fully with the spirit of the Directive. It was the first to be built in the Spanish state. It took four months to construct and the investment amounted to 31 million pesetas (186,313.7 ).