Isn't that what the government does? The short answer is no.
National and local governments in impoverished countries fail to provide basic services such as water and sanitation for a myriad of reasons. The government may be an unresponsive military or civilian dictatorship that fundamentally does not care about its people. Even democratically elected governments may have to cater to the whims of their elites rather than focus on the plight of the poor in order to maintain power. National and local governments frequently lack sufficient tax revenue to provide basic infrastructure and services. To the extent that the national governments depend upon aid from international financial institutions and foreign governments, they are prisoners of the priorities of the donor nations and agencies. These institutions often require that national governments build infrastructure to meet the needs of large industrial or commercial interests, rather than to meet the needs of the poor. For example, rather than create small scale community water projects and distributed electrical generation projects, donors like the World Bank, China, or the United States may fund huge dams to generate large quantities of electricity for industrial purposes and large quantities of water for massive corporate farms and plantations.
International humanitarian agencies like CARE, the International Red Cross, Church World Service, and others frequently focus most of their resources on short-term emergency aid, rather than longer-term development needs. The long term development programs that are created by international humanitarian agencies are frequently built on the basis of grant or contract funding from international financial institutions, donor governments, and foundations. When the cause celebre is no longer water and sanitation, when the world economy suffers an economic downturn, or when a developing country is subject to economic sanctions for a variety of geopolitical reasons, such funding disappears and individual donations to international NGOs suffer as well.
Under these circumstances, there is no reason to believe that national governments, international financial agencies such as the World Bank, foreign governments, or international humanitarian agencies dependent on direct mail and mass publicity campaigns can effectively assure that every person in the world has clean water to drink and sanitation adequate to prevent disease. Although political pressure should be applied on all of these institutions to demand that they provide essential services like water and sanitation, such campaigns are a highly uncertain and at best long-term means to solve the problem. The most immediate and effective means to give the world clean water and sanitation may be for relatively wealthy natural communities in developed countries or rapidly developing countries (schools, churches, service clubs, youth groups) to fund small community water and sanitation projects -- desired by the project community, designed and constructed by the project community with technical assistance and materials supplied by local and regional non-profit organizations indigenous to the area, and operated, maintained, and governed by the community.
How many projects will it take? We don't know. But, assume that international and national institutions will eventually provide water and sanitation for those in the cities. That means we must still provide 750 million people in rural areas with clean water and perhaps twice that with adequate sanitation. If a typical rural project serves 1000 people (some will serve 100, others will serve 5000), we may need over a million small projects. But consider how many communities there are in the developed and rapidly developing countries...many, many more than a million. And the point is...each community can start with a single project. Raise $500, $1500, $5000, or $15,000 to fund a cistern or sand dam for water storage in an area with seasonal droughts, rainwater harvesting or a basic water treatment system to treat water in areas of abundant rainfall, a shallow drinking water wells in areas with abundant groundwater recharge, or a deep well to access water in arid areas. The size of the project will vary with the size, wealth, and commitment built within the community that funds the project. But each of those projects contributes to the vision -- to make clean drinking water and adequate sanitation available to every human being on earth, so that no one need die of water borne diseases and so that the energy and resources currently devoted by poor people to obtaining water, fighting disease, and obtaining health care can be devoted instead to more fulfilling and profitable enterprises. And once a community funds a single community water project, it will want to fund another in a different village or perhaps build a school or a medical clinic in its first village. Once people's eyes are opened and they feel the joy of improving the lives of others, they never want to stop.
The advantage of these "village to village" community projects are numerous: