It looked like an April Fools' Day joke.
A pair of Porta-potties set up near a busy campus bus stop, student and faculty volunteers in T-shirts with "Pee Maize 4 Blue" written on the back, and a #peecycler Twitter campaign.
Researchers from the University of Michigan were serious though, when they asked people passing by to stop and donate their urine. It's all part of what researchers said is the nation's first "large-scale pilot project" for urine recycling.
“We’re taking this urine, doing analysis on it, seeing what’s in it, and turning it into fertilizer products," said Krista Wigginton, an assistant professor of environmental engineering at U of M. "We'll apply that to our test crops and see how the urine-based fertilizer does with the crops and also where the pollutants in the urine end up."
The university is collaborating with several institutions, including the Rich Earth Institute in Brattleboro, Vermont. Researchers there say they've used this type of fertilizer to grow lettuce and carrots in a test garden.
Wigginton said treating and reusing wastewater is a direction the U.S. needs to take.
"Right now, we deal with urine by diluting it, sending it to the waste water treatment plant, and then we try to remove it from the waste water steam," she said. "It's energy intensive, it's hard to do, and some plants don't even do it."
Wigginton said she hopes the event and others like it help start a national conversation about urine recycling.
There were plenty of confused stares from students and faculty passing by the urine-collection area on the way to class.
Some wanted to know more about the project but said they would have to come back later, when nature called, to donate.
Others were happy to oblige when volunteers urged them to "join the urine-nation," including U of M senior Catherine Culkin.
"It's like public urination, except you don't get in trouble for it," she joked.
Event organizers said they hoped to collect at least 50 gallons of urine before the day was through.