The reauthorized Safe Drinking Water Act (SDWA) of 1996 added provisions requiring all community water systems (CWS) to deliver annual water quality reports called Consumer Confidence Reports (CCRs) to their customers. With an estimated 46,000 CWS required to develop and distribute CCRs to their customers each year, the CCR requirement poses an important challenge for water utilities to disseminate information to their customers. The research reported here was conducted to evaluate the effectiveness of CCRs and to better understand the effect of CCRs on water utility customers, specifically to evaluate whether and how CCRs influence consumer perceptions, and what attributes of CCRs most influence consumers' perceptions. Developing effective communications is a deliberate process that can build on past experience and the experience of other water utilities and researchers. Toward that end, the authors sought input from a wide range of relevant sources that included previous research, water utility managers and staff, and the actual customers for whom the communications are intended. The authors' goals included: reviewing what is currently known about public perceptions of drinking water safety, the effect of water utility communications on those perceptions, and the research methods used to make those assessments; determining what water utilities are currently doing to meet the CCR requirements, and what information the CWS would find most helpful; reviewing and analyzing the content and attributes of the CCRs that water utilities are currently sending to their customers; linking those attributes with customer reactions in an experimental setting to determine what makes a CCR more "usable" for a customer and more "effective" for a water utility; assessing the current reach of CCRs and other water utility communications, and the impact these communications are having on customer awareness, perceptions, and attitudes about drinking water safety and their local water utility; and, integrating all of this information into a set of observations, conclusions, and recommendations that local water utilities can apply to evaluate and improve their own communications, including both the mandatory CCR and other voluntary methods. To achieve these goals, the authors used several different techniques to conduct primary research with the aim of better understanding CCR effectiveness. The research comprised five integrated tasks: Task 1 - a mail survey of 118 water utilities exploring what CWS are doing to meet the CCR requirements; Task 2 - ten directed micro-focus groups with water utility customers in five cities to explore customer reactions to reading CCRs; Task 3 - CCR attribute characterization, where 127 CCRs were coded on 95 attributes to explore what attributes are most important in determining the usability of CCRs; Task 4 - a national random sample of the general population, conducted via a telephone survey with 1,146 water utility customers and 268 well water users, to investigate the current reach and impact of CCRs; and, Task 5 - a central site survey with 152 water utility customers in three cities, which evaluated CCRs on multiple response scales to determine how customers react to CCR attributes. Includes 11 references, tables.