other necessary steps to assure that adequate laboratory testing capability and capacity are available for local water utilities.

OHS should work with DOJ and EPA, along with representatives of state and local water supply agencies, in seeking solutions. It is likely that the constraints are based in state law or county or local ordinances and so must be addressed there. These bodies should be ready to cooperate because it is their water supply that is at risk.

The four highest-priority areas for research on water security are physical security, monitoring and identification of biological and chemical agents, decision models and sampling, and interactions across infrastructures. In addition, there is a need to establish a national center of excellence to support communities in conducting risk assessments and to serve as a clearinghouse for communicating research results to the industry. The scope for such a center would become broad, and multiple branches with well-defined missions added when the need is defined.

The water infrastructure enjoys little physical protection. Much of the supply, transportation, and distribution system is unstaffed and readily accessible to the public. New methods for physically securing the system are needed, as are ways of continuously—or at least periodically—monitoring for intrusion across the large areas that water systems cover. As with other physical infrastructure systems, technology is needed to protect against explosives delivered by motor vehicle or rail. The American Water Works Association is currently sponsoring vulnerability and physical-security training for water system operators, and EPA is funding the national laboratories to conduct the actual training.

A significant issue in contamination of water is the early detection of chemical or biological agents in the system. While water supplies are routinely monitored for a few contaminants, they are infrequently tested for exotic contaminants that might be introduced by terrorists. Much can be done to improve the situation.

New sensors for better, cheaper, and faster sensing of chemical or biological contaminants in water are needed, based on sophisticated analytical techniques that are available in the U.S. chemical industry. These sensor systems should be small, distributed, resistant to interference, and robust against false positives. For