Mining nutrients from‘LIQUID GOLD’

  • The Urine Depot station at 116 Birge Street in downtown Brattleboro, Vt., where participating members can drop off their urine for collection by the Rich Earth Institute. Staff Photo/ZACK DeLUCA

  • Donors place their jug on the stand where they lower a tube in and vacuum up their urine donotaion. It is added to a holding tank, which is then brought to the Rich Earth Institute’s headquarters for sanitation and distribution to local farms. Staff Photo/ZACK DeLUCA

  • A “low-tech” solution allows donors to fill up their jug at home, and then bring it to the depot station downtown for drop-off. Staff Photo/ZACK DeLUCA

  • Arthur Davis, a researcher with the Rich Earth Institute, stands outside the urine depot station at 116 Birge Street in downtown Brattleboro, Vt. Staff Photo/ZACK DeLUCA

  • While people go to the urine depot to “do their business,” the depot features a music sheet, appropriately printed on yellow paper, for “Gold Into Straw.” The original song was written by Davis’ father, a retired elementary school music teacher, about the benefits of pee-cycling.  Staff Photo/ZACK DeLUCA

  • Farmers use a gravity-fed tank, drawn behind a horse or tractor, to fertilize their hay fields. The Rich Earth Institute’s urine fertilizer is currently being used on hay fields across Vermont. Staff Photo/ZACK DeLUCA

  • The urine depot also has a log sheet where participants can write down how many gallons of urine they have dropped off as part of a friendly, community competition. Staff Photo/ZACK DeLUCA

  • A urine diverting toilet displayed the Rich Earth Institute headquarters. Staff Photo/ZACK DeLUCA

  • A collection of different urine diverting toilets being studied and displayed at the Rich Earth Institute headquarters. Staff Photo/ZACK DeLUCA

  • Arthur Davis shows a sawdust composting latrine that he is building with the Rich Earth Institute. Staff Photo/ZACK DeLUCA

  • The Rich Earth Institute Co-Founder Abe Noe-Hayes. Staff Photo/ZACK DeLUCA

Staff Writer
Published: 6/1/2020 9:09:43 AM

Located just over the state line in Brattleboro, Vt., the Rich Earth Institute has spent the last eight years turning “liquid gold” into a viable fertilizer. 

The small research group operates “the nation’s first community-scale urination reclamation project,” and has been studying the use of human urine as a form of fertilizer for growing hay since it was founded in 2012. In its first year, the group collected and “pee-cylced” 600 gallons of waste. Last year, they collected more than 10,000 gallons. The organization has helped save over 1,116,000 gallons since its foundation.

“The project is one of the first of its kind,” said Arthur Davis, who directs the Urine Nutrient Reclamation Project for the Rich Earth Institute. “We’re producing something that has a great value for local agriculture.”

The Rich Earth Institute conducts original research on the safety and efficiency of urine-derived fertilizer. It uses its “first-in-the-nation” facility for field trials, and to develop urine processing and handling technologies. The organization works at the intersection of agriculture and sanitation as it studies the social and ecological implications of recycling human urine, which can help protect natural resources. The institute also works in partnership with the University of Michigan through a Natural Science Foundation grant.

Abe Noe-Hayes, who co-founded the institute in 2012 with Kim Nace, said he was interested in nutrient recycling in agriculture. He said he wanted to recapture the nutrients being lost in septic systems.

“If it goes into a septic, it’s lost and becomes pollution instead of a resource,” he said.

”Liquid gold” is an abundant source of sustainable fertilizer, if it's not flushed into sewers. Just like animal manure, Noe-Hayes says human waste can be sanitized and transformed into natural, sustainably-produced fertilizer. By using urine as fertilizer, it allows the nutrients — nitrogen, phosphorus, potassium and other elements essential to plant growth — to go back into the Earth and be consumed by plant life.

The organization started as a grassroots movement and quickly gained traction. It now has hundreds of participants in the greater Brattleboro area.

“It’s a gratifying thing to have your waste going to a productive purpose,” Noe-Hayes said.

Anyone participating in the Rich Earth Institute’s urine reclamation project is able to pick up a jug or bin to collect their liquid waste. If collected in a sealed glass or plastic container with a tight-fitting lid, all the fertilizer value will be preserved.

Participants bring their full jug to a drop-off depot station in down-town Brattleboro. The depot pump system uses a handle to lower a vacuum tube into the donation jug. One push of the button sucks up the donor's urine into a holding tank.

While people go to the depot to “do their business,” the depot features a music sheet, appropriately printed on yellow paper, for “Gold Into Straw.” The original song was written by Davis’ father, a retired elementary school music teacher, about the benefits of pee-cycling. There is even a log sheet where participants can write down how many gallons of urine they have dropped off as part of a friendly competition.

“The biggest donor of the year gets a trophy,” Davis joked.

Adults produce between 100 and 150 gallons of urine per year. This contains 9 pounds of nitrogen and .8 pounds of phosphorus. According to the Rich Earth Institute, if used to fertilize grain, this could be used to grow enough wheat to make a loaf of bread every day of the year.

The Rich Earth Institute brings the depot holding tank back to its facility on Old Ferry Road in Brattleboro, where it is pasteurized by running the urine through a system at 80 degrees Celsius for 90 seconds. Urine is already a form of fertilizer, Davis said, but pasteurizing removes all the pathogens in the urine.

Davis said one of the biggest reasons for the institute’s research is to avoid having these pathogens go back into water systems. Once in sewers, it can cause nutrient pollution that costs municipalities millions to remediate. When nutrients from urine enter the wastewater system, they are very hard to remove.

By flushing urine into the sewer system, its “fertilizing potential” ends up in rivers, lakes and bays where it encourages algae to grow. This can cause destructive algae blooms that eliminate oxygen in the water, killing fish and other aquatic creatures, causing foul odors and rendering water unfit for human consumption.

According to the Rich Earth Institute, The majority of nitrogen and phosphorus in wastewater “comes from one concentrated source that makes up less than 1 percent of wastewater volume: human urine.” Separating urine from the rest of the wastewater stream at the source has the potential to eliminate up to 75 percent of the nitrogen, and 55 percent of the phosphorous from wastewater systems without making changes to treatment plants.

By collecting and recycling urine into fertilizer, the Rich Earth Institute says municipalities can more affordably protect the aquatic environment, while replenishing the soils that support us. According to the Rich Earth Institute, urine contains most of the fertilizer found in human waste, but we flush it away each day.

“They say four out of five bathroom visits are just to pee,” Davis said.

The Rich Earth Institute says phosphorus is essential to farming. It is a non-renewable resource and high-quality reserves are steadily being depleted. The mineral is the source of synthetic phosphate fertilizer, and also the powdered rock phosphate used in organic agriculture. The good news is that by using urine as a fertilizer, the limited resource can be recycled indefinitely to grow new crops.

Urine also wins from a public health perspective. The diseases associated with poor sanitation are fecal pathogens, while urine is generally free of non-pharmaceutical pathogens. The research group is also studying the removal of pharmaceutical pathogens in urine. ​

Efforts to avoid fecal contamination in urine and make urine donation more accessible has led to the development of urine-diverting toilets, which can be placed in homes and collect urine odorlessly. These toilets have one bowl in the back of the toilet, and a small collecting area for urine in the front half. By separating waste, it allows for the collection of uncontaminated urine. Urine diverting toilets can use up to 80 percent less water than conventional toilets.

While urine-diverting toilets are more popular in Europe, Davis said it may be a few years before they start arriving in American homes. For now, a low-tech solution allows for local urine collection. Plastic jugs with handles and tight-sealing, threaded cap lids are the most popular system among home donors. Ammonia that develops in stored urine is a natural sanitizing agent, and will destroy any bacteria that may be present.

The 5-gallon container was developed by the Rich Earth Institute. A funnel top, with a ping-pong ball as a check valve, allows the urine to fall into the jug but keeps the air and odor from coming back out. Women either urinate directly into the containers or use a toilet insert to catch their pee and then pour it into the jug.

The Rich Earth Institute is also working on ways to improve storage capacity for their large-scale urine recycling. They are using technologies to concentrate the fertilizer in urine into a smaller volume. This will play an important role in making widespread urine recycling economically viable. The institute is developing reverse osmosis as a method to concentrate urine, while preserving its fertilizer value. Freezing, evaporation and vapor compression distillation have been proven to effectively concentrate urine.

Currently, the institute’s permits are for application on hay fields and farms in Vermont. Davis and Noe-Hayes both said the institute isn’t pursuing use trials on food for human consumption at this time. While the local community has been receptive to their program, they don’t know how much the general public would be on board with eating food fertilized with urine.

However, Noe-Hayes said use on food for consumption is “not an issue.” According to Noe-Hayes, studies of urine fertilizer use on foods like lettuce and carrots have shown no signs of health issues so far.

Davis also said there are many more hay fields in Vermont that aren’t using urine for fertilizing, and that would be the best place to expand. Davis said urine fertilizer has a high content of nitrogen, and grass is a nitrogen hungry plant, making it a natural partnership.

“There is so much hay in Vermont that there is no urgency for us to use it for regular agriculture,” Noe-Hayes said.

The Rich Earth Institute is looking for more donors, as demand for urine fertilizers from their participating farmers is also beginning to exceed their current supply. According to the Rich Earth Institute, it takes approximately 1,000 gallons of urine to fertilize one acre of hay fields.

In addition to his research work, Davis is the Festival Toilet Coordinator for the Rich Earth Institute. Each year the Rich Earth Institute sends one of their urine collecting toilets to be used at the Garlic and Arts Festival in Orange.

Zack DeLuca can be reached at zdeluca@ or 413-930-4579.

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