Green Gridirons: Northwestern University

A football stadium may have green grass but does it have green habits? Each week, Great Lakes Echo highlights a Big Ten football stadium’s attempts to do the most to impact the environment the least. All schools have information on the stadium’s diversion rate – the amount of waste recycled instead of put in a landfill. Stadium: Ryan Field

School: Northwestern University

Built: 1997

Capacity: 47,130

2012 diversion rate: 39 percent

Scouting report: Ryan Field began recycling bottles and cardboard on game day in 2008. Most recycling collections come from tailgate lots, said Julie Cahillane, Northwestern’s manager of recycling and refuse.

Green Gridirons: University of Iowa

A football stadium may have green grass but does it have green habits? Each week, Great Lakes Echo highlights a Big Ten football stadium’s attempts to do the most to impact the environment the least. All schools have information on the stadium’s diversion rate – the amount of waste recycled instead of put in a landfill. Stadium: Kinnick Stadium

School: University of Iowa

Built: 1929

Capacity: 70,585

2012 diversion rate: 52 percent

Scouting report: The Iowa Recycling Team has united with other school organizations to keep game days clean before, during and after football games. During pregame activities, 26 recycling bins are placed at the gate entrance of Kinnick Stadium for fans to drop their materials as they enter, according to Eric Holthaus, recycling coordinator at the school.

Green Gridirons: Purdue University

A football stadium may have green grass but does it have green habits? Each week, Great Lakes Echo highlights a Big Ten football stadium’s attempts to do the most to impact the environment the least. All schools have information on the stadium’s diversion rate – the amount of waste recycled instead of put in a landfill. Stadium: Ross-Ade Stadium

School: Purdue University

Built: 1924

Capacity: 62,500

2012 diversion rate: 18 percent. Scouting report: The university’s sustainability program received a $120,000 grant in 2012 to focus on tailgate recycling and diverting waste from landfills, said Michael Gulich, director of sustainability at the university.