This powerpoint presentation begins by providing a brief overview of enhancing laboratory preparedness, the Environmental Response Laboratory Network (ERLN), and the Water Laboratory Alliance (WLA). The Regional Drinking Water Laboratory Preparedness Four-Phased Project is presented and includes: developing a generic response plan template; facilitating meetings in each region to refine/customize plan template to meet the needs and challenges of labs in each region; table top exercises in each region to practice what the laboratories have agreed to in their customized plan; and, functional exercises in each region to further challenge and test the plan with blind, spiked samples, unknowns analyses, and data generation and transmission. Regional Laboratory Response Plan (RLRP) elements evaluated during FX are presented, along with the benefits of functional exercise participation, significant findings from the exercises, the Water Laboratory Alliance National Response Plan (WLA-NRP), and a full-scale exercise of the WLA-NRP. Includes table, figure.