The purpose of this paper is to describe the issues, new information, methods, limitations, and possible solutions for estimating exposure to drinking water, as a means of improving and standardizing methodsused by EPHT states. The paper is meant to provide the CDC Tracking Branch, the Drinking Water Content Workgroup, and the states funded to implement the EPHTN with an outline of what the relevant drinking water exposure assessment and surveillance issues are and provide insight into potential next steps and projects for the national EPHTN to take. These lessons learned and recommendations may serve as a foundation for the drinking water content workgroup and for use by tracking and non-tracking states to develop and implement drinking water surveillance and exposure assessment methods. By providing this guidance to the EPHT community, this report also serves to inform several other audiences about the need for improved surveillance capacity and enhanced tools and methodologies for EPHT in the area of drinking water and related exposure assessment.