Phytoremediation’s Roots: An Interview with Paul Thomas
Paul Thomas is the president of Applied Natural Sciences and has been working in phytoremediation for decades. We sat down with him to hear about the origin of the field and his career journey.
You’ve spent much of your career in “phytoremediation.” Can you briefly define the word and share about when you first heard it?
The term “phytoremediation” didn't exist when I started working in the field. The simplest definition is the use of plants to remediate environmental contamination. The term was coined by a professor at Rutgers—Ilya Raskin—while applying for a grant in 1991. He was one of two people at Rutgers involved in “phyto”—the other was Michael Blaylock. Raskin and Blaylock worked closely with Burt Ensley who was the president and founder of a company called Phytotech. They were focused on remediating metals, so the term “phytoremediation” came about because of the work that they were doing. Prior to ’91, the term was not used to my knowledge.
Where did your phytoremediation journey begin and how did you link up with Edward Gatliff, Applied Natural Sciences’ founder?
I had first proposed the use of plants to clean up an agricultural chemical site while working for Dames & Moore in 1987. I started working with Edd Gatliff in ‘88 when he came to work at Dames & Moore. He had been a research agronomist in Dodge City, Kansas. Even though I had the idea to use plants for environmental cleanup in ’87, I didn't really have the wherewithal to make it happen because, as a hydrogeologist, I didn't have sufficient knowledge of plant physiology, agronomy, and soil fertility.
I had a site in Illinois impacted by agricultural chemicals where I wanted to use plants to remediate shallow soil and groundwater. An Illinois EPA agronomist had been giving us a really hard time saying, “you geologists and engineers don't know the first thing about using plants to clean up agricultural chemicals—it’s a good idea, but you're out of your depth.” Edd showed up and started talking agronomy to this guy, and it was clear the EPA agronomist thought—finally you brought somebody that knows what they’re doing. That's how Edd and I started working together. It was Edd’s suggestion to use hybrid poplars, which we found to be quite effective and still use to this day.
TreeWell technology didn’t happen right away. We were experimenting for several years with different methods to overcome the limitations of phytoremediation for remediating deeper groundwater. The first TreeWell-like thing we tried was at a different site in Illinois, in the early ‘90s. The first prototype TreeWell unit was installed at a site in New Jersey in 1995, and he filed for the initial patent in 1996. We had been working on the concept for several years, trying different things.
What else was going on in the realm of phytoremediation in the early 1990s?
There were two different directions that phytoremediation was going in the early ‘90s. One was in the direction of metals remediation, and that's the one that people were pouring money into. I already mentioned Burt Ensley’s Phytotech and that was a highly capitalized, publicly traded company for a while. The other direction was everything else, which was Edd and me and Lou Licht (Ecolotree) and Ari Ferro (Phytokinetics) and a couple other people. The companies we started during that time were very small. We didn't have any investors. We just started off looking for projects, and we each had a few clients that were willing to spend money on this emerging technology. Interest really took off starting in the mid-90s when it was obvious that metals weren't the only thing that could be cleaned up using plants. We began building remediation full-scale systems in the field to clean up volatile organic chemicals and pesticides in soil and groundwater and had data to demonstrate effectiveness.
What are important milestones for you and what has sustained your passion throughout your career?
The most important thing for me was having the idea in 1987 to use plants to clean up a site that I was working on in Illinois. At the time, I didn't realize what that was going to turn into, but it has made everything else possible that I’ve done. When I left Dames & Moore to start my own company in 1989, it was with the thought that I wanted to specialize in plant-based remediation because it was such an exciting thing to me. I was young and naive about the risks of trying to make a business of phytoremediation, but also lucky to have one client that was willing to take a risk on this new technology and get me through the early years. But if I hadn’t taken that risk, it wouldn't matter if I was lucky or not. It certainly worked out for the best.
What I have enjoyed most about this career is its multidisciplinary nature. Phytoremediation requires a working knowledge of many fields including chemistry, microbiology, hydrogeology, soil science, plant physiology, and agronomy. I’ve enjoyed working in many places around the world and with many very interesting people.
