UI Water Sustainability Initiative - Craig Just

By Mallory Hughes


            Craig Just was born and raised in Iowa and calls himself a “lifelong Hawkeye fan.” When he saw an ad in the Des Moines Register for a lab director in the Environmental Engineering and Science Program, he could not answer it fast enough.  Twenty-one years later, Just is still at the University of Iowa. He is a researcher and an Assistant Professor of Civil and Environmental Engineering.

            “I like working with humble folks,” Just said. “We’ve got that sort of Iowa-type culture here.”

            Currently, Just is studying freshwater mussels. He said essentially he is looking at how they eat, poop, and puke with respect to the nitrogen cycle.

            “Mussels are filtered feeders and they graze on green plants and small organisms,” Just said. “From an engineering perspective, I like to study how we might restore river habitats to make mussels even more productive toward removing nitrogen from the water.”

            By allowing the mussels to remove the nitrogen from the water in their grazing, nitrogen might flow to the Gulf of Mexico and contribute to the Dead Zone.

            “I’m learning that freshwater mussels could potentially create more nitrate, which is easily transported to the Gulf of Mexico,” Just said. “That would be a negative research outcome in my mind because I want to advocate for freshwater mussels.”

            He also said that those findings are only on the lab scale, and that they could be wrong on the larger, environmental scale.

            “I’m finding that I don’t know all that I need to know about mussels and nitrogen processing,” he added.

            Just is also studying engineered vadose zones, using deep-rooted poplar tree systems to treat high nitrogen food processing waste. He explained that this could also be a resource but when the nitrogen is applied too heavily, it escapes the root zone and contaminates groundwater.

            “We’re just trying to maximize ecosystem capacity toward growing a variety of things,” Just said.

            In another area of his research, Just is looking at alternative wastewater treatment systems, keeping rural Iowa in mind.

            “Many of our wastewater treatment requirements for really small rural communities create a very large financial burden,” he said.

            By researching new ways to treat wastewater, they hope to effectively use less energy and have them cost less, making them affordable for the rural communities around the world.  Research in Iowa is particularly interesting because of the thriving rural communities and the rural-urban mix.

            “Unlike many other states, we just flipped over where we have more people in urban centers in Iowa than we do in rural centers,” he sad. “We need to keep rural Iowa viable in everything that it affords in the context of these growing urban centers.”

            This includes having fishable, swimmable waterways for everyone in Iowa. Another important thing is attracting and retaining individuals in the state by having useful amenities and remaining productive agriculturally.  One of the biggest challenges for Just as a researcher is keeping his portfolio diverse in order to receive funding from a variety of sources. He also said that the research time scales are a lot shorter now than they used to be.

            Just is the director of the Community Engagement Core, part of the Iowa Superfund Research Center, which has multiple researchers across campus. Together, they study airborne polychlorinated biphenyls (PCBs), their impact on human exposure, and remediation strategies.  He also teaches “Introduction to Sustainability” and “Design With the Developing World” at the University of Iowa.