Connecticut DOT Turns to Steam Technology in Fight Against Invasive Plants
Connecticut is battling over 100 non-native plant species that inflict environmental, economic, and health damage across the state, choking out native flora. The Connecticut Department of Transportation (CTDOT) is now employing innovative, environmentally friendly methods – Foamstream and AquaPro – to combat these invasive weeds, particularly in sensitive areas.
How Foamstream and AquaPro Operate
Both Foamstream and AquaPro utilize high-temperature steam to eradicate plants. Foamstream distinguishes itself with a non-herbicidal foam composed of coconut oil, wheat, grapeseed oil, and potatoes. This foam acts as a thermal blanket, retaining heat long enough to kill the weeds. AquaPro, operating at 212 degrees Fahrenheit, employs a direct steam application, effectively “washing weeds and killing them,” according to Chris Samorajczyk, supervising environmental planner for the CTDOT’s Central Maintenance Administration.
Targeted Applications and Early Success
Currently, the CTDOT is deploying these technologies in specific locations, such as paved islands and areas adjacent to watersheds. The agency began using Foamstream and AquaPro in 2024 and has found them to be effective, though not yet suitable for large-scale projects. “It’s really smaller, herbaceous weeds. It’s not really for any of the larger stuff,” Samorajczyk explained.
The equipment is compact – Foamstream fits in a pickup truck bed, and AquaPro in a small trailer – allowing for focused treatment. The DOT anticipates deploying the systems in communities starting in May, aiming for a single, season-long treatment rather than multiple herbicide applications.
Limitations and Future Development
Despite their promise, Foamstream and AquaPro aren’t a complete replacement for traditional herbicide use. The current technology isn’t suited for the DOT’s guiderail program, which requires a continuous, mobile application at speeds of 15-20 mph. Both systems require stationary application and multiple passes to ensure complete eradication.
The CTDOT is actively communicating with manufacturers about developing wand attachments for mobile application, but a viable solution isn’t currently available. “They can’t find where the heat holds to kind of run it in the way we need it,” Samorajczyk said. “They advise us they’re working on it.”
A Step Towards Reduced Herbicide Use
Andy Morrill, CTDOT’s maintenance manager of Special Services, emphasized that Foamstream and AquaPro are part of a broader effort to minimize herbicide reliance. “We brought those two pieces of equipment in to try alternatives to get to an end goal of either reducing or completely eliminating the use of herbicide,” Morrill stated. “Unfortunately, the industry and the technology is not there yet.”
The DOT already employs strategies to minimize herbicide use, including precise calibration of spraying equipment and avoiding application in regulated areas like wetlands and watersheds. They also spray under guardrails and avoid spraying into the wind.
Effectiveness and Ongoing Research
Samorajczyk noted a “high percentage of mortality” for smaller invasive species treated with Foamstream and AquaPro. However, the technology has limited effectiveness against hardier plants like mugwort or thicker weeds like goldenrod. The DOT continues to research and evaluate alternative solutions, prioritizing both environmental safety and employee well-being.
The state’s efforts extend beyond the DOT. The Connecticut Department of Energy and Environmental Protection (DEEP) supports invasive aquatic plant control through grant programs, addressing threats to waterways like the Connecticut River.
FAQ
Q: What are Foamstream and AquaPro?
A: They are environmentally friendly technologies that use high-temperature steam to kill invasive plants without relying on herbicides.
Q: Where is the CTDOT using these technologies?
A: Currently, they are being used in paved islands, barrier systems near watersheds, and other specific areas.
Q: Can Foamstream and AquaPro replace herbicides completely?
A: Not yet. The current technology has limitations, particularly for large-scale applications like guiderail maintenance.
Q: What is the state doing to combat aquatic invasive plants?
A: The Connecticut Department of Energy and Environmental Protection (DEEP) offers grants to fund projects aimed at controlling invasive aquatic species.
Did you know? The foam used in Foamstream is made from renewable resources like coconut oil, wheat, and grapeseed oil.
Learn more about invasive species in Connecticut from the Connecticut Invasive Plant Council.
Have questions about CTDOT’s vegetation management program? Share your thoughts in the comments below!
