Reduce, Reuse, Peecycle

Reduce, Reuse, Peecycle

Student Project Diverts Nitrogen-Rich Urine From Great Bay to Farm Fields
Thursday, April 17, 2014

Durham Urine Diversion and Recyle bus

Business major Liz McCrary ’14 and environmental engineering students Taylor Walter ’14 and Alyson Packhem ’14 want students to donate their nitrogen-rich urine for their senior capstone project. They’re exploring ways to divert the urine from the wastewater treatment plant and use it for fertilizer.

On weekend nights this spring, four UNH seniors approach their classmates with an unusual pitch: “Want to donate some nitrogen?”

The donation doesn’t involve needles or personal sacrifice; rather, donors simply relieve themselves in a custom-built porta-potty dubbed the Peebus.

Officially called Durham Urine Diversion & Recycle, it’s the senior capstone project for three environmental engineering students and a business major. They’re eliciting the help of their well-hydrated fellow students to divert nitrogen-rich urine from Durham’s wastewater treatment plant and onto actual plants, where it could be used as fertilizer.

Along the way, the students – environmental engineering majors Taylor Walter, Alyson Packhem, and Adam Carignan, and business major Liz McCrary – are educating their classmates to think beyond the flush.

“This is a feasibility study to see if people are accepting of the concept of urine diversion,” says Walter, the group’s project manager. “Everybody pees and nobody thinks about where your pee goes.”

In fact, it goes to the town’s wastewater treatment plant, where human urine comprises 80 percent of the nitrogen entering the plant. There, much of it is removed by state-of-the-art biological processing before entering the Great Bay Estuary, where too much of the nutrient can fuel excess algae growth and upset the balance of the estuary by robbing it of oxygen.

Yet that same high nitrogen makes urine a very productive fertilizer; a secondary goal of the project involves working with two local farmers to explore the use of pasteurized urine as a fertilizer for hay crops.

Urine diversion and recycling begins with urine collection: Over four weekends, starting March 20, the students have parked their Peebus at a well-traveled campus crossroad (a parking lot at the corner of Strafford and Garrison Avenues) between 11 p.m. and 1:30 a.m. to solicit “donations.”

The response, they say, has been overwhelmingly positive, with more than 200 students visiting the Peebus each weekend. “We had a feeling it would catch on, and it has,” says Walter. They generated significant buzz through word of mouth, news articles, and on Twitter (@peebus2014). “I donated my nitrogen” stickers, printed with a yellow droplet, spread the word as they become the spring’s must-have fashion accessory in Durham bars.

How does the Peebus work? Watch.

After three weekends, the students have collected about 40 gallons of urine. They hope to bring the Peebus to major events like the outdoor concert SolarFest, Durham’s Memorial Day Parade, and even UNH’s commencement. Farmers Dorn Cox of Lee, a Ph.D. student at UNH, and Ray LaRoche of Durham, who also works in the town’s public works department, are interested in testing the urine fertilizer on their hay fields.

The Durham Urine Diversion & Recycle students have been working closely with Durham town engineer David Cedarholm ‘94G, who initiated the project after noticing spikes in nitrogen entering the plant weekend evenings. Stricter environmental standards for reducing nitrogen into the estuary have the town considering a costly upgrade to the plant; Cedarholm wondered if there was another way to reduce nitrogen. He approached his former professor Nancy Kinner, professor of environmental engineering, who in turn pitched the project to the students.

“It takes eight gallons of water to transport one gallon of urine,” says Cedarholm, who drew inspiration for this project from the Rich Earth Institute of Brattleboro, Vt., a larger-scale urine reuse project. “People don’t realize that urine is actually a valuable resource.” In addition to mentoring the students, Cedarholm has supported the project from his budget.

“I’ve never worked with a group of students who are so engaged, all four of them,” he says.

As the project progresses, the students acknowledge that they’re unlikely to collect the 1,000 gallons needed to fertilize one acre of hay crop. But they’re upbeat that they’ve hit their goal of helping a wide audience understand the complex environmental issues behind the flush.

“People think this is cute and funny,” says Walter of the Peebus donors. “We’re doing them a service, they’re doing us a service, so it’s a win-win. And they learn something.”

And, she adds, “they get a sticker.”

Originally published by: 

UNH Today

Video by Scott Ripley, UNH Video Productions