What is White Infrastructure?

What is White Infrastructure?
The Garden Giant, Stropharia rugosoannulata, grows to a huge size.

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Green infrastructure is a proven strategy for stormwater management. But there’s something new on the horizon that could best be described as “white infrastructure.” It could also be described as game-changing. 

Paul Stamets, a mycologist in Olympia, Wash., has experimented with fungi for 30 years. He’s discovered some truly amazing things the “lowly” mushroom can do to help clean up waste of all types. His work began back in 1984, when he purchased land on an inlet of Puget Sound. That property had a failing septic system. 

“A few days after moving in,” says Stamets, “I was served with a court summons to fix my septic system within two years or incur fines.” He was in the process of setting up his new business, Fungi Perfecti, so cash flow was limited. That’s when he hit on an idea that could revolutionize stormwater management. 

“There’s a species of mushroom know commonly as the Garden Giant, widely cultivated as produce and quite tasty,” Stamets continues. “From my previous work, I knew this species (Stropharia rugoso-annulata) had some remarkable properties. Those raised in the sterile environment of my laboratory, using sawdust as a growing medium, always seemed a bit anemic. But when I used real soil instead, the Stropharia cultures grew vigorously. Stropharia thrives on bacteria, so I decided to try an experiment.” 

Proof of concept 

The septic field on his property was on a downhill slope, ultimately discharging into an inlet where the Olympia Oyster, a prized shellfish, supported the local economy. He also had agricultural runoff to contend with; his pasture was home to cows, chickens and pigs. The main issue addressed by the summons was fecal coliform bacteria. Outflow from his property had many times the allowed levels. 

“There was an 800-foot marshy swale between my land and the water,” Stamets says. “So I cleaned out the large debris, put down a bed of sawdust and wood chips, and spread Stropharia mycelium throughout the swale.” 

For all those non-mycologists, mycelium (shown on the left) is the root-like form for these fungi. It’s a white mesh-like structure that can be grown from spores, then transplanted where needed.

The mushrooms themselves are the “fruit” of the plant, and appear regularly when weather conditions stimulate reproduction. Spores come from the fruit, like the seeds of traditional produce. 

“Within the allowed two years, huge Garden Giants were popping up all over that swale,” Stamets continues. “And when my outflow was tested, fecal coliform had dropped by more than a factor of 100, well below acceptable levels — in spite of the fact that my livestock had nearly doubled in number. That was the genesis of my concept, now known as mycofiltration.” 

Methods and motivations 

Stamets does not utilize gene splicing or cross-breeding to produce the hundreds of cultivars he currently raises. He relies on a remarkable property inherent to all living organisms called epigenesis: the ability of organisms to express existing genes in novel ways depending on environmental factors. 

“For too long people have tried using technology to force nature to do their bidding,” Stamets says. “That’s the wrong approach, and often creates more problems than it solves. I could cite many examples. What we need to do is work with nature, allowing it to show us the amazing things it can do on its own. We just have to give it a chance.” 

Stamets was originally trained as a marine biologist, and later at Evergreen State College in Olympia, where he earned his mycology degree. When he graduated in 1979 he had studied under some of the world’s leading mycologists and become a highly accomplished field scientist, lab researcher and taxonomist. Soon after that, he decided to establish Fungi Perfecti and see just what he could do with these remarkable plants. 

Stamets has published several scientific papers and books on his mycology research. He’s also presented on TED.com, the online platform for conferences and discussions on technology, entertainment and design ideas; his talk titled "6 Ways Mushrooms Can Save the World" is an excellent summary of his personal approach to mycology. 

EPA gets involved

Stamets enjoys high visibility in the mycology business, so it’s no surprise that his mycofiltration research came to the attention of the EPA. In 2012, the EPA awarded him an $80,000 grant to develop a mycofiltration system that could be applied to manage stormwater runoff. Working with Marc Beutel, Ph.D,. and Alicia Flatt (Beutel’s graduate student) at Washington State University, and Alex Taylor, assistant research scientist at Fungi Perfecti, they did a comprehensive bench-scale analysis of a mycofiltration system for removing pathogens from stormwater. 

In practice, their mycofiltration system would be deployed in existing swales and detention basins. After setting down a bed of wood chips to help establish the mycelium, the fungus eventually becomes a permanent resident. The wood chips are reduced to soil over several years. 

Stropharia would be the most likely candidate, but other species could be included to target hydrocarbons, metals, tannins, and phosphates and nitrates from fertilizer runoff. Existing green infrastructure flora happily coexist with the fungi. 

Their research also uncovered a disturbing fact about existing water-quality tests: Standard protocols were generating false positives for fecal pollution. 

The false positive problem 

During their research, the team compared the efficacy of wood mulch colonized with mushroom-forming fungi to wood mulch without fungi to ascertain the effectiveness of mycofiltration. 

“One of the things we needed to look at was the accuracy of the EPA-approved testing method we employed, and just how reliable it was at detecting E. coli and fecal coliform,” Taylor says. “During several control tests, we put bacteria-free water through a bed of wood chip mulch (without fungi) and tested the effluent. Incredibly, ordinary wood and straw mulch exported bacteria that appeared on the tests as E. coli and fecal coliform. 

“After extensive DNA testing, we realized that there are two confounding issues at work. First, there are many bacteria that can produce a false positive for E. coli using the standard membrane filtration test. Second, many fecal coliforms grow naturally on wood and are not associated with feces at all. The approved test was significantly flawed in its ability to selectively detect E. coli. The fecal coliform test as an indicator of health risk is just outright meaningless.” 

When these variations were accounted for, the data showed mycofiltration media removed significantly more E. coli than wood chips alone. 

This information was included in their report to the EPA. Interestingly, just weeks after the conclusion of their research, the EPA issued revised recreational water-quality guidelines (based on several years of epidemiological research) that confirm several of these findings. Bottom line: Many administrative decisions, consent orders, landowner fines, and system design approvals, are being made on the basis of incorrect test result interpretations. 

Further applications 

The benefits of mycofiltration go far beyond stormwater management. This entire taxonomic kingdom (Fungi) has demonstrated efficacy in many areas. Current research by Fungi Perfecti, and other research groups, includes:

  • Petroleum spill cleanup
  • Removal of endocrine disrupters
  • Radioactive waste, and biological and chemical agents cleanup
  • Ecosystem repair and restoration
  • Floating mycofiltration systems that clean the water and feed fish
  • Antiviral applications
  • Medicinal applications for humans, including cancer treatment 

“This isn’t rocket science,” Stamets concludes. “I have just two rules: follow my intuition and listen to nature. I believe some of the biggest mistakes in science are made early in the decision-making process, when the initial assumption is how to force Nature to do what we want using technology. Nature speaks in many languages. If you can learn some of those languages, you’ll be better informed to proceed with experiments.” 

Stamets has been listening to nature for over 30 years. What he’s learned so far is remarkable, and there’s certainly more to come. Mycofiltration is just the first of a host of potential applications. “It can help save the planet,” he says. “We really believe we’ve got a game-changer here.”

How do you think this emerging stormwater management solution will benefit the industry? Leave a comment below.


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