June 17, 2026

Stopping Ballast Invasive Species in the Great Lakes

ELPC Is Fighting to Protect the Great Lakes from the Spread of Invasive Species by U.S. Lakers, Huge Cargo Ships That Operate Exclusively in the Great Lakes

By Wendy Bloom, Senior Attorney & Elise Zaniker, Associate Attorney

Right now, in the Great Lakes, up to 63 U.S. cargo ships known as “Lakers” are carrying up to 16.4 million gallons of ballast water in their tanks, containing countless unknown, and potentially invasive, living organisms. These Lakers take up ballast water in one Great Lakes location, then discharge in another, making them the single most important pathway for spreading invasive species throughout the Great Lakes.

In 2018, Congress passed the Vessel Incidental Discharge Act and gave EPA a clear directive – to set the most environmentally protective standards that require vessel owners to treat their ballast water. Instead, EPA ignored Congress and gave all existing Lakers a free pass to continue polluting the Great Lakes with invasive species without installing any treatment technology. So, we’re challenging EPA in federal court to fix this mistake.

Read Full Reply Brief

Separately, the industry association of U.S. Laker owners, the Lake Carriers’ Association (LCA), filed a lawsuit challenging EPA’s decision to require future Lakers not yet built to install ballast water treatment technology, and ELPC intervened in LCA’s lawsuit to ask the court to keep this requirement in place. We recently wrote a separate blog post about that lawsuit. And, LCA has intervened in our lawsuit arguing that EPA’s free pass for existing Lakers should remain.

Why are Ballast Water Management Systems important?

There is a viable and effective treatment option for these existing Lakers: Ballast Water Management Systems. These systems first filter and then treat the ballast water with ultraviolet radiation, chlorine, or other methods to kill living organisms before discharging the ballast water to prevent invasive species spread.

Decades of research have confirmed that Lakers can be retrofitted to install this technology, and that it would drastically reduce the likelihood of new invasive species establishment. Yet, EPA ignored this evidence, and Congress’ command, to allow Lakers to keep spreading invasives. In contrast, Canada requires its existing Lakers to install, operate and maintain Ballast Water Management Systems.

What is the Uptake BMP and why is it important?

EPA also made our Great Lakes less safe by getting rid of a common-sense, longstanding best management practice (Uptake BMP). It required all vessels, including those on the Great Lakes and ocean ports, to avoid taking up ballast water in areas with known infestations of invasive species. That includes hotspots near sewer outfalls, and in other types of water known to have harmful pollutants. EPA wants to replace this mandatory practice with voluntary compliance, weakening the current regulation and putting the Great Lakes, our waters, and coasts at unnecessary risk.

What did EPA get wrong?

Congress instructed EPA to apply the Clean Water Act’s most stringent standard—the best available technology economically achievable—when setting standards for ballast water discharges. At the very least, Congress required EPA to maintain the current standards. EPA did neither and instead issued even weaker standards.

In 2013, EPA required Lakers built after 2009 to install Ballast Water Management Systems and meet a numeric ballast water discharge standard. Five of the 63 existing U.S. Lakers were built after 2009. Now, EPA wants to backslide and exempt all existing Lakers from having to treat their ballast water at all. EPA also got rid of the Uptake BMP, even though multiple states, including Michigan, Wisconsin, and Minnesota, urged EPA to keep this common-sense best management practice in place.

What is ELPC doing to try to fix EPA’s unlawful conduct?

On Friday, June 12, ELPC filed a Reply Brief in our lawsuit, on behalf of ourselves, Alliance for the Great Lakes, Minnesota Environmental Partnership, and National Wildlife Federation. We are challenging the parts of EPA’s Final Standards that:

• Exempt existing Lakers from the requirement to install, operate and maintain BWMS
• Weaken prior regulations by failing to hold post-2009 Lakers to the numeric ballast water discharge standard and omitting the Uptake BMP as violations of VIDA in the D.C. Circuit Court of Appeals. A copy is here.

Our Reply Brief responds to claims made by EPA and LCA in opposition to our Opening Brief, filed on December 19, 2025. A copy of our Opening Brief is here.

In support of our lawsuit, Michigan’s Department of Environment, Great Lakes, and Energy, along with Illinois and Vermont, filed an amicus brief in the case, urging the Court to grant our lawsuit and explaining the importance of retaining the Uptake BMP and protecting the Great Lakes from invasive species. A copy is here.

Invasive species threaten the biodiversity and health of the Great Lakes. The lakes are already overrun with several invasive varieties, and communities around the region are fighting to hold back others. We have tools to fight the spread; we must use them.