Federal agency won’t start chemical treatment of Lake Mattamuskeet amid court case

The U.S. Fish and Wildlife Service will not begin experimenting with a chemical to try to remove harmful blue-green algae from Lake Mattamuskeet until at least April 2025, according to an order issued by U.S. District Court Judge Terrence Boyle.

Conservation groups Defenders of Wildlife and the N.C. Chapter of the Sierra Club have sued in the Eastern District of North Carolina to prevent the U.S. Fish and Wildlife Service from applying Lake Guard Oxy to four bays totaling 400 acres on the 40,276-acre Lake Mattamuskeet.

The chemical’s label states that it is toxic to birds, and Lake Mattamuskeet, North Carolina’s largest freshwater lake, is the prime feature of the Mattamuskeet National Wildlife Refuge. Mattamuskeet is an iconic eastern North Carolina landmark, known for the egrets, north pintail ducks and tundra swans that use it as a resting point on their migratory pathways.

“We’re all so relieved that these birds will not be exposed to toxic chemicals this year while the court reviews the legal problems with the Fish and Wildlife Service’s rushed and inadequate approval of this dangerous experiment,” Ramona McGee, a senior Southern Environmental Law Center attorney representing the conservation groups, said in a statement.

The federal government founded Mattamuskeet refuge to protect birds. Conservation groups argue that mission is directly contrary to the application of a chemical whose label says it is poisonous to birds.

The risk to wildlife is too high to use the algaecide, McGee argued during a hearing in Raleigh last month, particularly because Lake Guard Oxy doesn’t represent a permanent solution to Mattamuskeet’s water quality problems.

At the same May 31 hearing in front of Boyle, Young Kang, a U.S. Department of Justice attorney representing the Fish and Wildlife Service, argued the intent of applying the algaecide would be to create an environment where submerged aquatic vegetation could thrive in Mattamuskeet.

The lake has seen a total collapse of the vegetation, Kang said. Taking steps to allow it to thrive once again would provide vital food for birds that use the lake as a stopover while migrating, as well as those that live there year-round, he argued.

“Ultimately, what the service is trying to do here is to restore Lake Mattamuskeet to its former glory,” Kang said.

Before applying the chemical, the suit argues, the Fish and Wildlife Service must issue a statement finding its use compatible with the purpose of the refuge, evaluate ways to reduce algae other than chemical treatment, more thoroughly evaluate the impacts applying the chemical would have on wildlife, and produce an environmental impact statement, a more thorough analysis than the environmental assessment under which the service approved the project.

“The service failed to do its due diligence,” McGee said.

Jennifer Koches, a U.S. Fish and Wildlife spokeswoman, declined to comment on the agreement to delay the initial application of Lake Guard Oxy, citing the ongoing litigation.

In his order, Boyle indicated he plans to decide the case before April 1, 2025, when the next window to apply Lake Guard Oxy could open.

“We’re glad that common sense has prevailed and provided more time to scrutinize this flawed plan. We hope that closer review will prove that there’s no defensible reason why an algaecide that’s toxic to birds should be tested at one of this region’s most important bird sanctuaries,” Erin Carey, acting director of the N.C. Sierra Club, said in a statement.

Lake Guard Oxy’s path to Mattamuskeet

The projects has it roots in a $5 million allocation to the N.C. Policy Collaboratory that was part of the N.C. General Assembly’s 2021 budget, The News & Observer has previously reported. That allocation was carefully written to give “a preference” to chemicals that float on the surface and that time release their chemicals, two hallmark traits of BlueGreen Water Technologies’ Lake Guard Oxy.

Collaboratory officials previously told The News & Observer they did not have a hand in crafting the provision, which came shortly after BlueGreen Water Technologies hired lobbyists to represent its interests in North Carolina.

After choosing BlueGreen as the company to provide the algaecide, Collaboratory officials worked with company representatives to sift through five potential water bodies.

They settled on Lake Mattamuskeet, a shallow body of water that has for decades struggled with pollutants coming from runoff, allowing harmful algal blooms to thrive there. In addition to pollution, the lake has grappled with a large population of invasive carp which tear up the roots of submerged aquatic vegetation when they eat.

In 2016, Mattamuskeet was listed on North Carolina’s list of impaired waters because of heightened acidity and levels of chlorophyll a, a nutrient associated with pigmentation that is an indicator of algal blooms.

Before Lake Guard Oxy could be applied, the project still needed approvals from both the Fish and Wildlife Service, which manages the Mattamuskeet refuge, and the N.C. Department of Environmental Quality.

As those were ongoing, the Collaboratory was placing sensors in Lake Mattamuskeet to collect data about water quality. That work is still happening, Claire Revere, a Collaboratory spokeswoman, wrote in an email.

“The baseline data collection is ongoing, and the Collaboratory has made it clear to the vendor that subsequent phases of the project, including cost reimbursements for treatment activities, will depend on having all necessary State and federal authorizations in place,” Revere wrote.

Collecting data will be useful, Revere added, for understanding the impacts harmful algal blooms have an various water bodies throughout North Carolina.

In March, the Fish and Wildlife Service issued an environmental assessment for the project, approving the chemical for use on four bays, clarifying that the chemical would only be applied from boats and providing more specific details about when it would be applied to limit exposure to waterfowl.

The service also determined that because the project is a pilot and limited to a small proportion of the lake, a more in-depth Environmental Impact Statement is not necessary.

“This is not a huge, drastic approach. This is a very limited study,” Kang said during the May hearing.

But McGee argued that the risk to birds is too significant, even if the chemical is applied to a relatively minor portion of the lake. The Fish and Wildlife Service did not consider data from BlueGreen showing toxicity to some species of birds, McGee said,

“They’re basically saying, ‘Trust us. Just trust us,’” McGee told Boyle about potential toxicity..

McGee also argued that the service failed to consider whether a 2019 Mattamuskeet watershed restoration plan from the N.C. Coastal Federation would represent a better approach to cleaning up the lake’s water than application of the algaecide.

In May, the N.C. Department of Environmental Quality issued a certificate allowing Lake Guard Oxy to be applied to Lake Mattamuskeet beginning on June 1.

Days later, before the state’s window opened, the conservation groups filed their lawsuit.

NC Reality Check is an N&O series holding those in power accountable and shining a light on public issues that affect the Triangle or North Carolina. Have a suggestion for a future story? Email realitycheck@newsobserver.com

This story was produced with financial support from the Hartfield Foundation and Green South Foundation, in partnership with Journalism Funding Partners, as part of an independent journalism fellowship program. The N&O maintains full editorial control of the work. If you would like to help support local journalism, please consider signing up for a digital subscription, which you can do here.