Dear Friends,
We want to speak directly to the growing concerns about the use of herbicides—specifically diquat—to manage the spread of the Connecticut River strain of hydrilla.
Let’s be clear from the start:
We are not here to dismiss or invalidate anyone’s concerns. These concerns are real and valid. We’re here to provide a better understanding of why hydrilla management is critical, how treatment options have been researched and evaluated, and what safeguards are in place to ensure we protect both public health and our water ecosystems.
Why Are People Concerned About Diquat?
Recent news stories—like those from The Guardian—have spotlighted legitimate health concerns about diquat when used in agriculture, especially now that it’s replacing glyphosate (the main ingredient in Roundup). In these cases, herbicides are sprayed broadly, often drifting through the air where they are either inhaled or absorbed through the skin of people and animals nearby causing serious, real and documented damage.
That’s not what’s happening with the Connecticut River Hydrilla Project.
Let us be clear: Our lakes, rivers, and ponds are not being crop-dusted with chemicals. This is not a “spray and pray” operation.
How Diquat Works in Water
When used to control submerged invasive species like hydrilla, diquat is applied only where the plant is growing—directly into the water and at lower concentrations than that of agricultural use. It quickly binds to the leaves and stems of hydrilla and is no longer detectable in the water column after a short period.
According to decades of research, decades of use on aquatic invasive plants (including here in Connecticut) and regulatory reviews:
- At the low concentrations used in aquatic applications, diquat poses no risk to human health when applied according to the label.
- The risk to fish and aquatic wildlife is considered very low, and any observed effects are typically short-term and reversible.
- As with most chemicals, the key is the dose and exposure—similar to how medications are safe and effective at the right dosage.
So Why Use It?
Because doing nothing isn’t an option and manual control only causes it to spread faster. In most places where it has already taken hold, other non-chemical options are no longer feasible.
Hydrilla is one of the most difficult aquatic invasives to control. This particular strain—the Connecticut River strain—is hydrilla on steroids. If not addressed in its first or second growing season, it becomes very dense and spreads – fast.
It has already spread to multiple lakes and ponds in Connecticut. Some lake communities are considering restricting public access to their waters out of desperation.
Water utilities are bracing for expensive impacts. And right now, there’s no rapid response protocol available for those affected.
That’s one of the goals of the Connecticut River Hydrilla Project—to test and develop safe, science-based tools communities can use when hydrilla shows up in their waters.
What We Believe
We understand why people are uneasy. Using herbicides in water is a big deal and should only be used when absolutely necessary. That’s exactly why this project has been years in the making—studying what we’re dealing with, researching treatment options, and testing methods in discreet areas.
This is a really tough environmental challenge. It’s complex and cannot be reduced to sound bites. That’s why it’s extremely important to base decisions on:
- Science, not speculation
- Transparency, not secrecy
- Accountability, not shortcuts
- And above all, a deep commitment to protecting both people and ecosystems
So, even in the face of personal attacks and slander on social media – we’ll continue to ask tough questions, advocate for the highest standards, and work toward better tools to fight invasive species.
And we’ll continue listening. Good decisions for our water requires all of us.
Thank you for your concern, your curiosity, and your care for our waters.