Huntsville, Alabama

New to the top 10 list this year (score 7.035, pop. 158,216), Huntsville has devoted almost a third of its land to green spaces including undeveloped forest and nature preserves, along with public gardens, parks and waterfront. The city-funded Operation Green Team has been remarkably successful in their public education and city clean-ups, enlisting 12,000 volunteers in their 2005 effort to clean and green the city.

Thirteen percent of the population commutes by bus while a trolley is available for special events to reduce congestion, helping clean up their air. The hospital possesses its own light rail system to shuttle staff across its grounds. Although Hunstville relies on coal and nuclear power for the majority of its energy mix, homeowners can purchase solar or wind-generated energy through the Tennessee Valley Authority.

The city is also developing a first-of-its-kind industrial park: 100 percent of all water runoff, says Ben Ferrill, city of Huntsville planner, will be biofiltered with swales, wet ponds and dry ponds. Rooftop runoff is separated from parking and street runoff to capture pollutants on site before they reach the subsurface aquifer.