Rethinking waste

Students put urine to eco-friendly use

By Joel Kost
On March 21, 2014

Taylor Walter knew last spring that the time to choose a senior capstone project was rapidly coming to a close, but she wasn't concerned. The environmental engineering student, then a junior, was confident that the right idea would present itself, and she would get it done well.

Then, during her fundamental aspects of environmental engineering course (ENE 645), professor Nancy Kinner announced a once-in-a-lifetime opportunity to the class. Those interested could apply to work with the town of Durham to reduce nitrogen effluent going into the Great Bay, while paving the way to save the community millions of dollars and offer an astoundingly eco-friendly fertilizer to local farmers.

The method? Urine diversion. 

In other words, the chosen students would be collecting pee.

Urine's effects on economy, estuary

Whenever a toilet flushes, urine is sent to the wastewater treatment plant where it is treated to reduce its nitrogen levels and, in Durham's case, sent out into the Great Bay estuary. Nitrogen, a natural nutrient and fertilizer, is essential to the sustainability of estuaries. 

Too much nitrogen, however, is hazardous. Nitrogen will fuel the growth of algae, resulting in more oxygen consumption. Fish, plants, and everything else that depends on oxygen will essentially be unable to breathe.

To monitor how much nitrogen is released into the estuaries, the Environmental Protection Agency regulates how much a town's wastewater treatment plant can filter out. 

In 2009, the New Hampshire Department of Environmental Services released a draft for a nutrient criteria report concerning the Great Bay estuary, claiming that the annual average of milligrams of nitrogen per liter should be no greater than 0.3 mg/L. Such a number would only be achievable if a town's annual average of effluent nitrogen in wastewater is 3 mg/L. 

Durham's wastewater treatment facility releases an annual average of 8 mg/L, but because the facility is reaching capacity, the town is required by the state to make an upgrade.

David Cedarholm, Durham's town engineer and UNH alum from the graduate program, said that the next facility upgrade, which will cost around $6-$8 million, would allow the town to put out an annual average of 5mg/L. Since the town has to upgrade the facility, building a plant that puts out 3 mg/L of N, which would add another $6-$8 million upgrade, would be costly and unnecessary.

In addition, a facility that puts out such a small amount of nitrogen requires the use of chemicals, likes the hazardous methane, to drive the biological process of filtering the water. The technology is certainly possible, Cedarholm said, but between the potential dangers and cost of chemicals (half a million dollars annually), it is not something the town would like to consider. 

"That is something we're really trying not to do," Cedarholm said of the 3mg/L upgrade. "No one at the waste water plant is interested in going that route."

At the end of the day, Durham eventually needs to reach that goal. But forking over millions of dollars isn't the only option. As long as the town reaches that 3 mg/L of nitrogen effluent, Cedarholm said, it shouldn't matter where the nitrogen reduction occurs.

"We don't actually know if we really need to go to three," he said. "We're trying to find lots of things, low-cost things, that will help us achieve the equivalent 3 mg/L."

Urine diversion is just that. The wastewater treatment facility sees a peak of nitrogen influent on the weekends when there's increased activity in town. If those peaks can be reduced year round, Cedarholm believes that it could reduce the annual average of nitrogen effluent to 3 to 4 mg/L by the time the new upgrade is implemented.

Inspired by the Rich Earth Institute in Brattleboro, Vt., a urine diversion project is the method of collecting human urine, sanitizing it to kill the pathogens and using it as fertilizer for crops. Urine naturally contains nitrogen, phosphorus and potassium, all of which are beneficial to plant growth.

It's part of Cedarholm's watershed integration program, in which wastewater sources like runoff, storm water and water from the treatment facility can be treated without pumping millions of dollars into facilities and chemicals. 

Urine accounts for about 80 percent of nitrogen entering the treatment facility; 10,000 gallons of collected urine a year could make the difference between upgrading the treatment facility a second time.

"It's an unusual [idea], but we have the student population that sounds like they're game, and they're quite the generators of urine," Cedarholm said.

Cedarholm had the idea to recruit students looking for capstone projects to assist him for a couple years. He bumped into Kinner, one of his graduate professors, last year and told her about it. It was that spring that Kinner offered the project to her students.

Crossing boundaries

Walter said Kinner's offer was so unique that it was too good to pass up; she approached Kinner the moment class ended.

"I didn't think much of it," Walter said. "I got up and said, 'Nancy, sign me up.'"

Fellow environmental engineering students Alyson Packhem and Adam Carignan, and business major Liz McCrary, joined Walter shortly after. 

But after the initial excitement, reality set in.

"Then I got a bit nervous," Walter said, questioning if such a project would even be possible in a college community. 

After all, the research was focused on collecting human waste, a topic that isn't freely discussed. The students had no idea how the student body would receive the idea, or if students would even accept the idea of someone collecting their urine. 

According to Kinner, it's this cultural boundary that the project must first overcome if it's to be successful. 

"We just have to get people to think that this is a good thing, that it's a more acceptable thing," Kinner said.

The Rich Earth Institute is successful because it depends on a small community that willingly donates urine. Students in a college community of about 10,000 aren't as likely to take time out of their day to donate; the idea must be presented to the student body through public outreach, education and conversation.

It's a conversation that all four students say should - and needs to - happen.

"People don't talk about the bathroom. And people use the bathroom and flush it all away and don't even think about it," Packhem said. "We've become so separated from our waste that we've become unaware of what it contains. The toilet doesn't make things disappear."  

Putting it all together

By the time September rolled around, all four of the students' excitement built up again. They constantly discussed how they should go about tackling such a project, whom they should talk to and how they should reach the student body. 

After naming the project Durham Urine Diversion & Recycle, they created a Twitter account for the project under the handle @Peebus2014 for further outreach and developed an interest survey, in which over 50 percent of students interviewed expressed interest in participating.

It was eventually decided to use a mobile trailer, dubbed the Pee Bus, with urinals hooked up to a 264-gallon cube to collect the urine for the start of the project.

The only downside to using urinals is that women won't be able to donate urine. Aside from the obvious logistical factors, using an actual toilet instead of a urinal adds the risk of feces being added to the urine. In addition, factoring feces into the project would add a whole layer of disease risks, cultural boundaries and challenges, Kinner said.

Kinner said that figuring out how to implement toilets that can separate urine and feces is something that future team members have to discuss as the project moves forward, but, for now, gaining awareness and acceptance is key. 

"It's the engineering practicality that we have to look at next," she said. "The practicality of collecting women's urine is much more difficult. This is an easier way to start."

Opening night

The Durham Urine Diversion & Recycle project made its campus debut Thursday from 9 p.m. to 1 a.m. next to the Elizabeth Demerit House. The team, alongside Kinner and Cedarholm, welcomed passersby to come learn more about their project and urine diversion. 

The results were mixed, with some students promising to return when they "had to go," while others were simply uninterested. Fifty-five people donated their urine by the end of the night, measuring to about seven gallons.

"There were a lot of people that said, 'Whoa, this is the coolest project we've ever seen,' and other people called us weirdoes," Walter said over the phone.

It wasn't quite the success the team was looking for, but Walter said they learned what to improve on next time. They will be in the same location this weekend.

"It was obvious that this was very new other people. I think we have to work on how we ask people what they want to hear," she said. "We asked if they want to use the bathroom, and I think that's a jarring thing to ask somebody. I'm looking forward to it improving."

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