#1 Arizona State 
University at Tempe 51,500 students, Tempe, Arizona

With the nation's second-largest student population, Arizona State University can make a big impact with small changes. Although the Sun Devils have not switched entirely to xeriscaping with native plants, they have phased out wasteful flood irrigation from more than 70 percent of the campus and now water most of the grounds at night. Last fall ASU inaugurated its School of Sustainability, where students learn about--and create--land-use and urban-planning models that minimize harm to the environment.

Waste: Partnered with a nearby farm to compost organic waste.
Purchasing policy: Requires paper products to have at least 30 percent postconsumer recycled content

Energy: Although it has signed the presidents' pledge and intends to buy carbon offsets, ASU hasn't drafted a plan to reduce its carbon footprint.

Score: 87