han comprehensive way), subsequent responsibilities were taken over by municipal provision by the beginning of the 20th century. Interest in environmental protection for receiving waters did not develop until the 1960s-70s although most countries had some form of wastewater treatment by then. After the Second World War most of the Eastern European systems were managed under centralised state control, rather than at a municipal (city) level. In the latter part of the 20th century, most European cities introduced separation between the storm and sanitary drainage systems, although due to historical instillation, most sewers in Western Europe are still of the combined type; only new systems are separate. Few countries - the Netherlands and many cities in the United States are notable exceptions - are attempting to retrofit systems for the separation of storm and sanitary wastewater. In London for example, there are plans for a new combined storage sewer at a cost of USD 3 billion, which uses essentially the same technology as for the originally constructed interceptor sewers in the 19th century (Thames Water, 2005). Renewed interest in private operation and ownership of water services emerged in Europe in the 1980s-90s. Despite this, the only fully privatised services for water and sewage in Europe are in England and Wales; in the other constituent countries of the United Kingdom, these services are provided differently. Various other forms of private involvement exist, ranging from simple contracting services to partnering and municipal or state-owned dedicated companies. Even state operation can be varied, with federal operation in some countries, municipalities in others and segregation between the various water service components (water, sewage, storm water) in others. Mohajeri et al. (2003) provide a comparative review of private sector involvement within the water sector across the (then 14) member states. Diversity is and will remain a main principle of the EU, and these various forms of service provision are