DONALDSONVILLE, La. — Louisiana regulators have issued the final air permit for Hyundai-POSCO Louisiana Steel’s planned $5.8 billion mill in Ascension Parish, clearing a major regulatory hurdle for one of the largest manufacturing investments underway in the state.
The Louisiana Department of Environmental Quality posted the permit this week for the proposed facility near Donaldsonville. The project broke ground ceremonially in September, but company officials said construction requiring the air permit could not begin until the authorization was issued.
The mill is planned for a roughly 1,700-acre site in the RiverPlex MegaPark on the west bank of the Mississippi River. It is expected to produce about 2.7 million metric tons of steel annually and begin operations in 2029.
Project estimates call for approximately 1,300 direct permanent jobs and more than 4,000 indirect jobs. The development is intended to supply automotive-grade steel and become an anchor industrial tenant for the much larger RiverPlex property.
The final permit follows months of public debate over both the economic benefits and environmental effects of the project. A September public hearing lasted more than four hours and drew testimony from supporters who emphasized jobs and investment as well as residents and environmental organizations concerned about emissions and impacts on nearby communities.
Hyundai-POSCO revised portions of its permit application during the review process. According to reporting on the final permit, changes included replacing nine natural-gas-fired industrial heaters with electric heaters, adding selective catalytic reduction systems, using additional ultra-low-NOx burners and improving particulate-matter controls.
Those revisions are projected to reduce annual greenhouse-gas emissions by roughly 294,000 tons compared with the earlier application, along with reductions in nitrogen oxides and particulate matter.
Environmental groups remain opposed to the permit. The Sierra Club argues that the state should have required additional electrification, stronger dust controls and a commitment to green hydrogen. The organization has said it is reviewing potential legal options. Those are the group’s allegations and policy positions; LDEQ’s issuance of the permit represents the state regulator’s determination under the permitting process.
The project has also generated disputes over public incentives and transparency. The State Bond Commission approved up to $1.3 billion in tax-exempt financing connected with the development in September, while litigation and public-records disputes have focused on confidentiality agreements and other aspects of negotiations surrounding the project.
The air permit does not resolve every approval or legal issue associated with the mill. A U.S. Army Corps of Engineers permit related to dock infrastructure has also been part of the project’s development process.
Still, the state air authorization is a consequential step because it allows the project to move from ceremonial groundbreaking toward more substantial construction activity.
For Louisiana, the mill represents a test of the state’s strategy of pairing large industrial incentives and infrastructure support with projects intended to create long-term manufacturing employment. For nearby communities, the test will also include whether promised jobs and economic activity materialize alongside the environmental protections required by regulators.
The debate surrounding Hyundai-POSCO is therefore unlikely to end with the permit. But the regulatory milestone moves the $5.8 billion project another step closer to becoming an operating steel mill on the Mississippi River.
Sources
Louisiana Department of Environmental Quality — Hyundai-POSCO public permitting record
WBRZ — Hyundai-POSCO receives air permit, Oct. 28, 2026
10/12 Industry Report — Final permit and emissions-control revisions, Oct. 28, 2026
WWNO — State Bond Commission financing and project disputes, Sept. 18, 2026
