For developers working on projects at least one acre in size, stormwater management is a key concern. In planning these developments, they must consider how to handle rainwater.
A mother-and-daughter duo in Columbia hopes two basins installed in the ground at Rock Bridge Memorial State Park could become the model f0r a solution to rain flow problems. The basins are part of a device that originated in the University of Missouri Department of Civil and Environmental Engineering. They come from the office of department’s “Wonder Woman.”
That’s what a fellow faculty member put on Kate Trauth’s nameplate as a joke. Around 10 years ago, Trauth, a professor in the department, began thinking about a three-dimensional structure to manage stormwater. Around that time, she drew the first drafts of a new device. In 2016, she received a patent for the device, and Trauth started a company, Infiltronics Environmental, as part of an agreement with the university.
The same year, Kate’s daughter, Ginny Trauth, graduated with a degree in engineering, joining her mother, father and sister in becoming an engineer. Not long after that, Ginny Trauth started working for Infiltronics.
“It’s nice, because there’s a trust, and I feel a responsibility,” Ginny Trauth said of working with her mom. “It’s a good mix of, I want this to succeed, and I want to work hard at this. And she’s kind of hands off as much as I want her to be hands off, and lets me do my thing. I come back, and we talk and we discuss and figure things out.”
With Infiltronics’ first employee came its first money — funding from the National Science Foundation I-Corps program, which helps scientists commercialize their research. As part of the program, the duo traveled around the U.S. — mother and daughter, together 24/7.
“We spoke to consulting engineers, city engineers, contractors, developers, installers, people who do kind of different stormwater management technology to really understand how everything works, and kind of get a better understanding of the business side of things, or the real-world side of things,” Ginny Trauth said.
Returning to the laboratory after their travels, the pair began putting the invention together and testing it. After a while, they began looking for their first field site.
Fighting flooding, erosion
Infiltronics does not offer a one-size-fits-all solution for managing rain flow. To install a device, the team first needs to study a site, understand what problem rain flow causes and then tailor parts and equipment to fit the particular environment.
Where stormwater tends to concentrate, they install a basin to collect water. From there, the water flows into tubes filled with varying amounts of gravel, sand and geotextile fabric. The tubes divert water to different locations on the site. The end goal is to spread out the stormwater, moving it to places where it can naturally soak into the soil. This can be helpful when water either flows too fast, eroding soil, or pools in one place, causing flooding.
Despite posing problems for a variety of properties, erosion and flooding are sometimes overlooked.
“When you come in, and you’re going to add impervious area … your thought process is that that’s not causing any damage,” said Kori Thompson, an engineering supervisor for the city of Columbia.
“Basically, what you’re doing is collecting (stormwater flow) and concentrating it, which results in more flow, and then also faster flow rates, that then picks up pollutants that it carries to the local waterways.”
Even if the stormwater running from a property increases in volume, the rate at which it flows should remain the same. However, there is a balance to be maintained.
“If the system is not designed to allow the water to leave quickly, then you have the opportunity for flooding,” said Enos Inniss, a professor in MU’s Department of Civil and Environmental Engineering. “If (stormwater flow) is moving too quickly — that is, if you have an area that doesn’t have a lot of vegetation — then those are the situations where you’re going to get more erosion.”
A first field test
The first site that Trauths chose to test their device on was struggling with erosion. Tolton Regional Catholic High School in Columbia is perched on top of a hill overlooking the Perry Phillips Lake. During heavy rain, stormwater runs from a 6,000-square-foot roof into a pipe that releases water at the top of a slope. At the foundation of the slope, a stormwater pond collects the torrent. With each rainfall, the water flowing from the pipe to the pond was destroying the slope more and more. The school could have done a variety of things to stop that, but it chose to give Infiltronics a shot.
“There are a lot of options, really, to deal with that,” said Tom Wellman, an engineering specialist with the city of Columbia. “One is just strengthening the ground that the water flows over. And so sometimes you can reinforce the turf. … Another way to handle that is just by detaining the water and letting it out much more slowly, depending on the situation.”
In August 2017, Infiltronics began its installation of the $5,000 device at Tolton. A basin in the soil under the pipe collects water, keeps waste away and reduces clogging. The water flow is then split into two sides to continue flowing through 25-foot tubes filled with different concentrations of sand and gravel wrapped in geotextile material to keep them intact.
“Maybe, in the beginning, you have … more gravel to move the water more quickly, and towards the end of it, maybe use more sand because it’s smaller, it slows the water down a little more,” Ginny Trauth said.
To install a device, the Trauths need to study the location and figure out the exact proportions of sand and gravel in the tubes. They also put sensors on the device to check its efficiency.
“Since we’ve done the installation, we saw there’s no erosion happening off the base of the pipe or off of our basins or anything like that,” Ginny Trauth said.
Gathering data, seeking certification
In March, Infiltronics signed an agreement with the Missouri Department of Natural Resources to install two devices at Rock Bridge State Park.
“The installations are very different, because one is dealing with a very steep hill taking a lot of water. The other one is dealing with water in a drainage ditch that’s taking water from a playground and that part of the road and all the other things,” Ginny Trauth said. “So we’re getting to play with two different installation methods in one area with different soil.”
To fund the installation, the duo decided to start a Kickstarter campaign with a $30,000 goal. It brought attention and connections, but it didn’t net the desired money.
“If we were to do it again, we would probably get some more time to get a little more buzz for officially launching the Kickstarter,” Ginny Trauth said. “Because by the time we started getting more and more attention, it was too late in the process.”
Instead, Kate Trauth used her own money to fund the installation, which they completed July 10. The Rock Bridge project is supposed to help the company refine its devices.
“I think they’re pretty preliminary,” Thompson said. “And where they’re at with that, I think they’re still kind of trying to gather up and do test installations and gather data.”
The data will be used to get a certification that Infiltronics needs to be able to charge for the devices.
There are dozens of options for managing stormwater. However, developers in Columbia can choose only the ones in the Stormwater Best Management Practices manual developed by the Mid-America Regional Council, a Kansas City-based nonprofit.
“We would like to get our device included in the MARC manual as a device that is known to work, and that engineers can look at and say, ‘OK, I’m going to put this in my plan for this site that I’m developing,'” Kate Trauth said.
For now, when developers in Columbia are given a stormwater manual to choose best practices to manage their rain flow, 40-50% of them choose a practice called bioretention. It involves a vegetated, shallow surface depression that uses the interaction of plants, soil and microorganisms to store, treat and reduce runoff volume.
Kate and Ginny Trauth believe they can offer another viable option.
“As we make these upgrades, and as Infiltronics gets the development of its devices up to speed, then I would think the two would come together,” Wellman said, “and it would be part of the future mix of options.”