Agglomeration ‘Agglomeration’ shall mean a zone that is a conurbation with a population in excess of 250 000 inhabitants or, where the population is 250 000 inhabitants or less, with a given population density per km2 to be established by the Member States. Non-agglomeration A zone delimited by a Member State for the purposes of air quality assessment and management which does not fullfil the requirements of an agglomeration