Long Island Tops the "Hit List" of Most Populous Non-Fluoridated Communities compiled by the CDC and they suggest state and federal mandates to achieve success.

http://www.mchoralhealth.org/PDFs/ImprovingCareforChildren.pdf

Table 4: The 15 Most Populous Non-Fluoridated Communities

Long Island, New York 1,239, 564 [really closer to 3 million people]

San Jose, California 979,000

South East Pennsylvania (Philadelphia suburbs) 820,000

Bergen and Hudson Counties, New Jersey 764,820

Tucson, Arizona 675,000

Fresno, California 485,000

Eastern Municipal California (Moreno Valley, Perris, Hemet, Murrieta, Temecula, and San Jacinto) 458,000

Baton Rouge, Louisiana 385,272

Colorado Springs, Colorado 360,890

Newark, New Jersey 275,221

Passaic Valley, New Jersey (Clifton, Passaic, and Paterson) 275,000

Reno, Nevada 270,000

Riverside, California 259,738

Jersey City, New Jersey 238,000

Rockland County, New York 225,000

Source: Centers for Disease Prevention and Control

This table appeared in, "Improving Oral Healh Care for Young Children," by Shelly Gehshan & Matt Wyatt, which was published by National Academy for State Health Policy, April 2007

Note the Authors’ acknowledgements

The authors are sincerely grateful for the time and expertise of the following people who reviewed and gave comments on drafts of this report: Dr. Jim Bramson, Dr. Al Guay, and Dr. Laura Neumann of the American Dental Association; Tim Lynch and Megan Fitzpatrick of the American Dental Hygienists’ Association; Dr. David Nash of the University of Kentucky; Dr. Ron Nagel of the Indian Health Service; Meg Booth of the Children’s Dental Health Project; Beth Mertz of the Center for Health Policy Studies at the University of California; and Andy Snyder of NASHP. This report was produced with the generous support of the National Oral Health Policy Center.

Among their solutions or "Findings" is fluoridation, of course:

States and communities should reconsider their efforts to ensure equal access to community water with optimal fluoride levels. Despite being one of the top ten public health accomplishments in the 20th century, fluoridated water is still under-utilized as a source of dental caries prevention. Rural communities without access to fluoridated water might consider fluoridating water in their schools.