on water systems, because it is essentially impossible to prevent an attack. There have been a couple of attempts that did not work, but there have been no thought-through attacks by individuals or groups such as state-supported bioterrorists or local militia types.

Multiple barriers to attack have limited effectiveness in the likelihood that an attack spread beyond a few people; the goals are to minimize the damage. If there was a bioterrorism attack, it would be a unique event, so water systems are not going to put a lot of effort into preventing an attack. Monitoring tools are being worked on as a means of response.

Not many people will have access to weapon contaminants, so there is not a need for very many labs to be able to analyze those. False positives are bad, because we do not want to scare the public, but a false negative is much worse. Current technologies for analysis are crude and include very broad parameters. It would be useful to be able to have some technologies that could be performed on a real-time basis.

Technologies are becoming available now for cleanup and disposal, such as thin film-type technologies for specific contaminants, but more technologies would be better. They can start being distributed, but there is not a huge need for that. If contaminants get into a distribution system, there will be miles of system to clean up. A small consideration is that some of those agents will be fairly persistent at times.

Over the next five years, simple removal technologies utilizing disposable media are needed for small utilities. Control of arsenate, perchlorate, n-nitrosodimethylamine, and methyl tert-butyl ether is needed. Ion exchange is great if it can be done. There are large-scale applications in the perchlorate area. The Colorado River has a chlorate concentration of 4-5 parts per billion (ppb), and it is conceivable to have a future regulation in that range.

The best way to work on water quality is to go upstream to Henderson, Nevada, where the contamination originates and try to eliminate the problems there. However, that feat would take some work. As mentioned previously, a better distribution system disinfectant would be helpful.

For 10 or more years from now, it would be ideal to have the technologies ahead of the regulations. Control of persistent organics in the brine and sludge disposal technologies is needed. The long-term trends should be to control the organics and clean up the water to customer satisfaction because there is more to water quality that meeting standards. There is a persistent pressure to control things that people worry about, and the health information is not available for backup.

Don Phipps, of the Orange County Water District, stated that on the control side of biofilms, some interesting technologies have recently been getting the attention of the media. There are also new surface-active biocides, chemicals that can be covalently bound to surfaces and will limit the proliferation or attachment of bacteria. He mentioned that he thought it might be an interesting process to try to develop pipe liners that are coated with these compounds and see if someone can gauge a test to determine if this would help limit the proliferation of biocides in the pipes. Mr. Phipps said that limiting the proliferation of biocides has a couple of advantages, including the reduction of the disinfection load required to maintain a residual. If the proliferation could be limited, the efficiency would be increased for the standard liner, and the total microbial load distribution system could be lowered.

Dr. Macler said this would reduce the demand on the residual. However, he said the real issue would be the stability of the biocide on the surface. How would you get the residual on the surface to begin with?

Mr. Phipps thinks the way these biocides really operate is that they are bound to the surface. They are not an exchangeable biosynthetic.

Dick Carlson, of San Diego County, commented that in his county there are a number of American Indian casinos using recycled water because they need waste distribution as a result of the waste load. They actually have anecdotal evidence of recycled water being used inside one of the casinos for toilet flushing, which is not a problem. However, this has been connected to the drinking water system in the same casino. He wanted to know who regulates this kind of activity.

Dr. Macler explained that the EPA is responsible for regulating those activities. He said that under the Safe Drinking Water Act, EPA develops and promulgates these drinking water regulations and the states can take on the authority to implement them to gain primacy. American Indian tribes have some sovereignty, but EPA deals with their lands. The agency has direct implementation authority and handles the situation with the tribes. He said that more tribes are running these casinos in California and they are growing from small-

Front Matter (R1-R12)

Executive Summary (1-4)

Context and Overview 1 Meeting the Global Water Challenge (5-10)

2 Green Chemistry: The Impact on Water Quality and Supplies (11-18)

3 Methylmercury Contamination of Aquatic Ecosystems: A Widespread Problem with Many Challenges for the Chemical Sciences (19-26)

Water Quality and Supply: Analysis and Treatment4 Desalination: Limitations and Challenges (27-39)

5 Organic Contaminants in the Environment: Challenges for the Water/Environmental Engineering Commmunity (40-46)

6 AquasentinelSM: Biosensors for Rapid Monitoring of Primary-Source Drinking Water (47-52)

Business Opportunities and Responsibilities7 Some New Approaches at the Orange County Water District (53-59)

8 A Perspective from a Water Company (60-65)

9 Sustainable Development: Role of Industrial Water Management (66-74)

10 Water Solutions and Strategies in the Chemical Industry (75-80)

11 Classifying Drinking Water Contamination for Regulatory Consideration (81-86)

Appendix A: Workshop Participants (87-88)

Appendix B: Biographical Sketches of Workshop Speakers (89-91)

Appendix C: Origin of and Information on the Chemical Sciences Roundtable (92-92)

Appendix D: For Further Reading (93-94)