establishes the legal basis for concessions to municipal and multi-municipal water and sanitation companies established under private law (typically publicly owned shareholder companies that are part of AdP). As mentioned above, these have come into widespread use in Portugal ever since. Águas de Portugal With total assets amounting to around €7.5 billion, the AdP Group is the largest entity operating in the environmental sector in Portugal. The AdP Group was founded in 1993 and set the mission of developing multi-municipal water supply and wastewater sanitation systems and currently providing services to over 80% of the Portuguese population. The core activity involves the integrated management of the urban water cycle and spanning all of its respective phases, ranging from the capture, treatment and distribution of water for public consumption to the collection, transport, treatment and disposal of urban and industrial wastewaters and including their recycling and reutilisation. Through its different companies, the group has a nationwide presence, providing services to municipalities that simultaneously serve as shareholders in the companies managing multi-municipal systems ("upstream" systems), and directly serving the populations through municipal systems ("downstream" systems) providing water and sanitation systems. In recent years, in association with local partners as well as other Portuguese companies in this sector, the group has undertaken a diverse range of projects in countries including Angola, Algeria, Brazil, Cape Verde, East Timor, Morocco, Mozambique and Sao Tome e Principe, whether in the format of technical assistance or the management of water and wastewater concessionary services. Currently, the group is present in Angola, where it set up a subsidiary in 2010; in Mozambique through its stake in Aquatec; and in various other countries following the signing of service provision and technical assistance contracts. Map of service areas of water and sewer companies EPAL – the water company serving Lisbon Empresa Portuguesa das Águas Livres, SA (EPAL) is a special case. The water company serving Lisbon and surrounding municipalities is a fully owned subsidiary of Águas de Portugal, in charge of bulk water supply and of water distribution. EPAL is the company responsible for the delivery of water to households in the capital (Lisboa) where it has around 350,000 clients. In terms of its bulk operations, EPAL supplies water to 35 municipalities on the north bank of the river Tagus and, since 2015, delegated management responsibility for the multi-municipal water supply and sanitation systems of Lisbon and the Tagus Valley,