Authorisation request

The application for the discharge authorisation must indicate the quantitative and qualitative characteristics of the discharge and the annual volume of water to be discharged, the type of receiver, the point at which control sampling is to be carried out, the description of the overall discharge system including the operations related to it, any system for measuring the discharge flow (where required), the equipment used in the production process and in the discharge systems, the treatment systems used to achieve compliance with the emission limit values.

Depending on the type of company, activity, technical characteristics and classification of sewage discharged, there are different types of authorisations. The main ones are:

  • AUA (Single Environmental Authorisation) 
  • AIA (Integrated Environmental Authorisation) 
  • Authorisation pursuant to art. 124 of Italian Legislative Decree 152/06 
  • Authorisation pursuant to art. 208 of Italian Legislative Decree 152/06

Assimilation declarations

As required by Italian Legislative Decree 152/06 art. 101 paragraph 7, sewage from certain types of production activities, identified by the same Legislative Decree 152/2006, and coming from other types of activities for which reference is made to regional legislation, may be assimilated to domestic sewage. For the Metropolitan City of Milan, Regional Regulation no. 6/2019 and the Integrated Water Service Regulation identify additional types of sewage similar to domestic sewage. For more information on assimilation, visit the website of the  Metropolitan City of Milan ATO.

Authorisation transfer

If changes arise related to ownership of the authorised company, legal representative or the like, a transfer must be requested. Requests can be submitted to the Metropolitan City of Milan online, using the Inlinea platform.



If you need support or more information, please contact our customer service team.

customer service

800 428 428