Started in 2006 as the initiative of the Mayors of Helsinki and Turku, nowadays the Baltic Sea Challenge grew to be a network of 250 member organisations from many countries around the Baltic Sea. The initiative invites all the interested organisations to commit in protecting the Baltic Sea and their local waters, to build and implement own Baltic Sea Action Plan.

As a politically independent, non-profit association, CCB is a network of 18 organizations from Belarus, Finland, Russia, Estonia, Latvia, Lithuania, Poland, Germany, Denmark, Ukraine and Sweden. Combined, the CCB organizations have over 850 000 members in all countries surrounding the Baltic Sea. Its main goal is to promote the protection and improvement of the environment and natural resources of the Baltic Sea Area, while encouraging new and constructive approaches and engaging people to become part of the solution instead of part of the problem. CCB reaches its goals throght support of their member organisations, concrete co-operation projects, lobbying and information, environmental education and other activities.

The Council of the Baltic Sea States is an overall political forum for regional cooperation. Consisting of 11 Member States as well as a representative of the European Union, it supports a global perspective on regional problems, including politically and practically translating the UN Sustainable Development Goals, the Paris Climate Agreement, the Sendai Framework on Disaster Risk Reduction, the Palermo Protocol and the UN Convention on the Rights of the Child, into regional actions on the ground. The organisation focuses on themes such as societal security, sustainability, research & innovation, as well as countering human trafficking.

HELCOM was established to protect the marine environment of the Baltic Sea from all sources of pollution through intergovernmental cooperation. HELCOM vision for the future is a healthy Baltic Sea environment with diverse biological components functioning in balance, resulting in a good ecological status and supporting a wide range of sustainable economic and social activities.

Union of the Baltic Cities is the leading network of cities in the Baltic Sea Region focusing on supporting cities' smart, sustainable and safe development. UBC works through 7 Commissions, among which Sustainable Cities Commission is responsible for the work on sustainability issues, coordinating the UBC Sustainability Action Programme and managing projects.

UBC Sustainable Cities Commission's scope covers both the field of urban water management and urban planning, sustainable mobility and climate adaptation topics. The Commission has successfully led several large transnational water projects (BSR WATER, IWAMA, PRESTO, PURE) and has been a partner in many more international initiatives.

The association (DANVA) is the interest organization for those working professionally with water and wastewater supply. It is an independent nonprofit association that ensures a stable and efficient water and sewer supply at a high quality level and on an environmentally sustainable basis. DANVA enables its members to influence on the policy agenda and support their main and related related activities (such as climate work) by initiating and promoting knowledge dissemination, development and cooperation in the Danish water sector.

A non-profit organisation that is a nationwide voluntary association of water companies providing the service of public water supply and sewerage and other business operators related to this area of activity. Association (later EVEL) consists of 74 members, of which 47 are waterworks and 27 - related companies (producers, constructors, consultants, rerailers etc.). Member waterworks cover about 90% of Estonian population, which are connected to public water supply and sewerage system. EVEL is assisting their members through involvement in legislative, educational, and informational activities in the water-sewerage sector nationally in Estonia as well as on the European and international levels.

Water Association of Finland, founded in 1969 to promote co-operation between different sectors of water branch, is a national, independent non-governmental organization with ca. 500 members (20 corporative) broadly covering water affairs. The purpose of Water Association Finland is to increase and disseminate information on hydrology, limnology, water ecology, fishery, water supply and sewerage, hydraulic engineering, water protection, water use and water legislation. The main activities are professional seminars, study tours and publishing.

Consisting of 7 regional groups, the association's 14000 members represent the specialists and managers of municipalities, universities and polytechnics, engineering offices, authorities and industry. Its core competences lie in the fields of technological research, producing rules and standards, certification, training, informational services and networking, aiming at connecting theoretical and practical levels of water management.

The association of over 40 members unites waterworks companies, institutions and specialists from Lativa for a common, aim driven task to provide good quality water supply and sewerage service.

An independent, non-profit organization the association consists of 56 member water utilities and companies. It provides consultancy assistance to the authorities responsible for water management in the state regulation of water supply and waste water management and management issues, preparation of legal documents, their practical application, the collection and compilation of necessary statistical data, training of personnel, certification and other issues.
 

Created in 1998 as a response to the professional community’s need for development of professional skills, capacities and exchange of information, the Association's mission is to present from the WWTP operator’s prospective the actual status and needs of the Polish water and wastewater sector ensuring at the same time more efficient environmental protection by collaboration in identifying best operational practices. Its aim is to achieve the highest global operational standards through efficient WWTP management involving optimal service quality and reliability with an ongoing commitment to minimize costs and ensure transparency. Currently, the Association consists of 179 regular members representing over 100 WWTPs, 33 associated members and about 800 non-members and is steadily expanding.

The association was set up by the municipalities in 1962 to assist with technical, economic and administrative issues and to represent the interests of the municipalities in negotiations with authorities and other organisations on regulations. It consist of 289 municipalities as its members, and main activities include publishing a journal, newsletters and reports. SWWA collects and evaluate statistical data, compiles recommendations and guidelines, and arranges seminars and short courses for the members. Association has several ad hoc working groups with experts from member municipalities covering the whole field of municipal water and wastewater activities.

EUREAU is the European federation of national associations of drinking water suppliers and waste water services. EUREAU’s members represent more than 10.000 drinking water and waste water utilities across Europe that provide sustainable water services to more than 400 million European citizens in both EU member states and outside. EurEau promotes the common interests of the members within the EU institutions and enables them to adequately deal with opportunities and threats arising from EU policies and their national implementation.

This one of the major professional associations in Europe is an independent non-governmental and non-profit organisation dealing with the management and improvement of the water environment. The subject fields cover the whole water sector, wastewater as well as drinking water and water related waste. With member associations from nearly all European countries, EWA consists of most European Union Member States, as well as several other countries such as Albania, Serbia, Norway, and Switzerland. The aim of EWA is to provide a forum for the discussion of key technical and policy issues affecting the growing European region. This is done through conferences, workshops, meetings and special working groups of experts all organised on an international basis together with regular publications.

Initiated by the European Commission in 2004 for Research and Technology Development in the water industry, the platform was transformed into an independent legal entity under Belgian Law in 2007. It envisions guidelines for future research and development for the European water sector, and strives all to make the European water sector a leading centre of expertise for providing safe, clean and affordable water services while protecting nature by 2030. WssTP consists of 178 members representing industry, research, technology providers, policy makers and water users. The network functions via 16 thematic working groupds and regularly produces scientific reports aimed at the advance of recommendations for Research and Technology development and Innovation within the European water sector.

Members and staff of IWA are situated in 130 countries worldwide, forming the largest international network of water professionals working towards a water wise world. IWA Programmes on Basins of the Future, Cities of the Future and Water and Sanitation Services establish change agendas on key themes for a water-wise world that contribute to sustainable development. In shaping and furthering these agendas, IWA engages with a variety of individuals and organisations through projects, events and publications.