Legislation No. 152/99 and the services for collection and treatment of urban waste water-An estimate of the required investment and the impact on tariffs in the optimal territorial area No. 2 'Lower Arno Valley'

摘要

Introduction of the European directive regarding the safeguarding of water supplies was performed in Italy through the Legislative Decree number 152/99. This legislation set new quality standards and new levels of service, particularly for the collection and treatment of urban waste water. The study was performed by the Department of Civil Engineering of Florence University and the Area Authority n. 2'Lower Arno Valley'. It set the objective of quantifying and defining the level of investment required to meet the new European standards and its tenability through an increase in the tariff of the integrated water utility. In the analysed territory, the Optimal Territorial Area 'Lower Arno Valley', the necessary interventions have been defined for upgrading the degree of coverage of the sewage system to serve all inhabited centres with more than 2000 inhabitants within 31/12/2005 and, within the same time scale, interventions for the upgrading of existing depuration facilities or construction of new facilities have been planned. Overall, it has been estimated that 47,5 thousand million lire will be required in the first five years to extend the sewage system to cover another 70 000 inhabitants and to upgrade or construct depuration facilities for over 617 000 equivalent inhabitants. By application of the normalised method introduced in the Ministerial Decree 1/8/96, the impact on tariffs has been calculated for these new investments. An estimate of the maximum annual increased was of circa 110 lire per cubic metre for the integrated water utility tariff for the year 2006, which is the year with the maximum level of investment, finalised towards the fulfilment of the requirements of legislation 152/99.