Port and harbors have expanded dramatically in the last few decades at a pace driven by rapid globalization of commercial trade and industrial activity, population expansion in marine regions, and the transfer of public and private wealth to coastal recreation. The impacts of ports oil coastal environments can be considerable. The development of industrial facilities at ports and associated demands for water, land, and shoreline is unavoidable given their potential national and global economic significance. Just as the international community has increasingly become aware of the importance of ports and harbors, there has been a growing awareness of the need to ensure that health, environment, and safety are adequately protected and considered as an integral function of these facilities. This increased awareness has led to a closer examination of environmental security. At the NATO Advanced Research Workshop, Risk Management Tools for Port Security Critical Infrastructure, and Sustainability held 16-19 March 2006 in Venice, Italy, a working group of international risk assessment, disaster response, environmental modeling, and engineering experts from nine countries explored the importance of environmental security and challenges faced by coastal ports and harbors. The discussions drew heavily from experiences at ports located around the world. This chapter summarizes the findings of the working group and concludes with a summary of technical challenges and recommendations for future research.