As fans reared up on their feet, whistling and whooping for Bowdoin’s football team, seniors Emi Gaal and Dana White guarded their game posts: four large trash bins. “We’re helping people sort their trash!” they explained, and directed the nearest heaver of a half-eaten hot dog to the appropriate bin.

Bowdoin has competed in the EPA Game Day Challenge for the past three years. The challenge pits colleges and universities against one another to see which one can divert the most waste from the landfill during an athletic event. “Football is generally the most wasteful event,” Gaal explained, “because there’s tailgating and barbecues, and [the trash] adds up fast.”

Much of the waste generated at a football game — from paper plates and plastic bottles to scraps of bread and napkins — can be either recycled or composted. Most people just don’t know which goes where. Here’s the test. Redeemable? This would be containers such as coke cans, bottles and glass. Recyclable? These items might be solo cups, cardboard or aluminum, which get reprocessed and reused. Food scraps go to a local farm to feed a herd of pigs. Paper waste, such as napkins, biodegrades in a compost back to soil. By taking an extra two seconds to sort trash, we save millions of tons of waste from stewing in landfills.

Behind the four trash bins, Gaal and White kept a pair of scales. At the end of the game, they calculated the amount of waste Bowdoin diverted from the landfill to submit to the inter-scholastic competition.