2.1 This part considers how the Department's objectives were translated into criteria used to compare options, and how it appraised alternative solutions.
2.2 The Urban Waste Water Treatment Directive (the Directive) generally requires member states to collect and treat all waste water in normal climatic conditions. Recognising that unusual weather may render this unfeasible, the Directive requires member states to decide on measures to limit pollution, such as an acceptable number of overflows in a year. The Directive does not set thresholds that define compliance for Combined Sewer Overflows (CSOs).