How do you sustainably filter stormwater to irrigate crops?
CSU Spur Water TAP lab aims to find out
story by Allison Sylte
published March 7, 2024
Late last year, a seemingly nondescript black shipping container made its way down National Western Drive and through the garage doors of the Colorado State University Spur campus’s Hydro building, capping off a 1,400-mile journey from Atlanta and the beginning of an effort to experiment with a more sustainable water treatment technology.
“Getting it into this building wasn’t easy,” said Todd Shollenberger, the manager of Spur’s Water Technology Acceleration Platform (TAP) Lab, who helped guide a forklift carrying the unwieldy container over sloped concrete into the facility. “But now that it’s here, it will unlock some of the endless possibilities for this space.”
What’s known as the Minus Water Treatment System is one of the newest technologies inside Water TAP. This shipping container houses a membrane-based ultrafiltration unit that can remove contaminants from stormwater without using more common treatment methods like chemicals or the energy required with ultraviolet light.
Sybil Sharvelle, the technical director of Water TAP and a professor in CSU’s Department of Civil and Environmental Engineering, said the Spur campus’s location in the heart of Denver offers a unique opportunity to test this technology.
“We obtain our stormwater from a roughly 20-acre area that’s heavily industrial and commercial, introducing a litany of contaminants,” she said. “This means that we really get to challenge the system, especially because the quality of stormwater can be highly variable and hard to predict.”
That’s where collaboration comes in. The Minus system came to CSU from Georgia Tech, and scientists from the two institutions will work together to develop a machine learning model to make its process more efficient.
“This project represents one of the first efforts of using a membrane filtration system for stormwater reuse, which is an essential strategy of enhancing the resiliency of our water supply in the context of climate change,” said Tiezheng Tong, an associate professor in the Department of Civil and Chemical Engineering who is involved in the project. “It also innovatively applies machine learning to process control, providing a novel avenue to increase the efficiency and reduce the cost of the entire system.”
The goal is that this treated water will be the necessary quality to be used to irrigate edible crops for livestock or human consumption.
“I think this is a really unique problem to try to solve, and since stormwater is often just wasted, it can have applications on a much larger scale,” Sharvelle said. “This really enables the lab to go to the next level.”
One lab, six sources of water
In addition to stormwater, the scientists at the Water TAP Lab can draw on five other sources:
- Greywater.
- Roof runoff.
- Wastewater.
- Water from the nearby South Platte River.
- Water trucked in from a variety of different sources, encompassing everything
- from hydrofracking waste to agricultural runoff.
This water is stored in tanks scattered throughout the lab, and can be pumped through a variety of different treatment systems, including 10 constructed wetlands that incorporate plants for potential filtration.
Sharvelle said the ultimate goal is to figure out more efficient ways to use local water sources and potentially reduce the demand on finite resources like the Colorado River.
“The whole purpose of the lab is to enable the testing of technology to move development and policy forward,” she said.
The Minus system is just one example of the technologies that will make their way through Water TAP in the coming years, and in addition to offering a real-world example of new filtration solutions to businesses, down the line, Sharvelle hopes it can also make the Spur campus itself more efficient in its water usage.
“The hope is that the water treated by the Minus system can be used to irrigate the plants on the green roof at Terra,” Sharvelle said. “The CSU Spur campus offers us endless opportunities to collaborate and test what we do in the real world.”
SOURCE Special Report: Solving the water crisis
CSU has been at the forefront of hydrology for more than a century since Elwood Mead, the namesake of America’s largest reservoir, became the first head of the Department of Civil and Environmental Engineering in 1883. This special report from SOURCE explores the research happening at CSU and provides insights into the ongoing water crisis across the country and around the globe.
