This citizen's guide to ensuring a safe supply of drinking water for all provides the information and analysis that individuals need to understand the issues and to participate in local decision making. The sources of drinking water, the types of human activities that results in contamination, and the contaminants that are of most concern are discussed. The workings of a typical treatment plant, who is responsible for ensuring the safety of drinking water, the requirements and effectiveness of the federal Safe Drinking Water Act (SDWA) of 1974, and the substantive changes made by the 1986 amendments to the act are described. Next, this guide surveys the various problems and issues in the management of drinking water. Discussions on how best to provide safe drinking water, what is considered safe, and what it will cost to provide a safe supply of drinking water are topics of discussion. The handbook concludes with a Guide to Citizen Action, designed to help readers learn more about the quality and management of local drinking water and to take action on issues of local concern as well as protect home water supplies. A glossary is provided, followed by a resource list that includes publications, national environmental organizations, health information organizations, professional membership organizations, state drinking water contacts, and organizations represented by contributing authors. (KR)