Students representing all 12 Houses and the three Freshman Yards put on purple gloves and plastic aprons yesterday morning to participate in Harvard’s fifth annual waste audit.

As students sorted and weighed 100 bags of trash from around campus, Pringle cans and soda bottles were sprawled out on tables and sorted into buckets near the Science Center. Unopened cookies and candy were found among discarded dining hall plates, cups and spoons, said Wendy H. Liu ’03, Resource Efficiency Program (REP) co-captain.

The purpose of the audit was to characterize the components of Harvard’s trash and to determine which buildings are throwing away recyclable items.

“The main question is how well are we separating our recyclables from our trash,” said Robert M. Gogan, associate manager of solid waste and recycling of the Facilities Maintenance Operations.

Trash was collected randomly from residential, academic and administrative buildings.

Gogan showed the students on how to separate the trash into five categories of recyclables.

“At least half of the waste by weight and volume is related to food,” Gogan said, referring to the ubiquitous pizza boxes, soda bottles and snack bags found in previous years.

This waste audit was also the largest in its history, as in previous years, workers sorted through only 50 bags.

While the waste audit previously was completed primarily by University employees, this year—for the first time—it was fully student run, said Rachelle K. Gould ’03, co-captain of REP.

The program is part of a University initiative to increase environmental awareness and promote resource conservation.

“My goal is to increase environmental consciousness among Harvard students because so many just never think about the environmental impacts of their actions,” Gould said. “It’s not a part of their calculations.”

While Harvard is making a concerted effort to focus more on recycling education, administrators say it could still learn much from other schools.

“Harvard does not look too good compared to other large public universities like UMass-Amherst or the University of Ohio,” said Gogan.

Harvard has seen a positive trend toward recycling since the audit began in 1998, Gogan said.

Harvard recycled 23 percent more paper this October than last year.