The Environmental Public Health Tracking Network (Tracking Network) is a national surveillance system that integrates environmental hazard, exposure, and health outcome data into one system. The Tracking Network launched in July 2009, and has since been receiving data from 23 funded state and local health departments, and several national partners, e.g., Environmental Protection Agency. Despite this success, some challenges exist in obtaining more timely and complete data to link risk factors, and assign exposure for health outcomes with long latency periods before their detection.