79/311/EEC: Council Decision of 19 March 1979 concerning the conclusion of the Agreement on a concerted action project in the field of treatment and use of sewage sludge (COST Project 68 'bis')

1979 COST research coordination agreement on sewage sludge treatment and use; advances organics/biological-cycle circular economy by funding collaborative research into sludge valorization pathways (land application, composting), though as a historical research framework rather than binding regulatory mandate.