 of on-site sanitation in countries such as the United States. Such systems can recover nutrients and energy and also be linked to local water supply and reuse technologies. In the United States, on- site sanitation systems now comprise some 40% of all new developments (USEPA, 2002). This potentially changes the approach to service provision in the future, with systems being smaller and requiring much less up-front capitalisation for their implementation. Decentralised systems are also better at coping with the need to expand services. In the area of storm water drainage, there is also a growing use of "source control" technologies that handle storm water near the point of generation, i.e. locally, also providing opportunities for direct use for, e.g., toilet flushing. A large number of small wastewater systems will require business models different from the large centralised systems traditionally used. In countries like the United Kingdom and France, moves to decentralisation could be more difficult due to the service providers being larger and concerned INFRASTRUCTURE TO 2030: TELECOM, LAND TRANSPORT, WATER AND ELECTRICITY - ISBN 92-64-02398-4 © OECD 2006 5. THE IMPACTS OF CHANGE ON THE LONG-TERM FUTURE DEMAND FOR WATER SECTOR INFRASTRUCTURE to maintain their core centralised infrastructure systems. In developing countries, decentralised systems are seen by many as the only affordable option (e.g. Werner et al., 2004). Estimates of the average costs of infrastructure provision in developed countries are given by Lee et al. (2001) and are summarised in Table 5.6. These figures are undated but presumably are current for 2000 and for French conditions, and relate to service standards that are generally accepted in Europe. The water supply costs do not include large dams or similar infrastructure as this is locally specific. Table 5.6. Costs of water supply and wastewater infrastructure for centralised systems US dollars Sewage disposal: Separate Service Water supply¹ Combined Separate sanitary storm water sewer1 s