Environmental and social impact assessment
Oklahoma Primary Aluminum is conducting an environmental and social impact assessment (also known as an ESIA) which will inform the development of an environmental and social management plan.
The impact assessment process is in line with best international industry practice as defined by the Equator Principles and the World Bank Group’s Environmental, Health, and Safety Guidelines (IFC 2007). Developing an impact assessment follows a series of steps evaluating the project’s potential environmental, social, and economic impacts as visualized below. It enables the local community and other stakeholders to participate in the identification and review of the project’s potential impacts, and mitigation measures that can be implemented.
How environmental review works - understanding the ESIA process
Environmental and social considerations:
Socio economics
Independent socioeconomic studies will estimate direct and indirect job creation, business activity, and local and state tax revenues.
Potential changes in community services and infrastructure will be identified so local and state partners can plan effectively.
EGA and Century are committed to prioritizing local hiring and procurement wherever possible.
Environmental and social considerations:
Air quality
Best-available air pollution control technology will be used, including advanced scrubbers and emissions reduction systems.
Air dispersion modelling will simulate how emissions move
under different weather conditions to confirm all federal and state standards are met.
Monitoring will be ongoing throughout the life of the facility, with results reported transparently.
Environmental and social considerations:
Noise
Baseline noise monitoring will record existing conditions before construction begins.
Future noise levels will be predicted using acoustic modelling.
Findings will guide equipment placement, building orientation, and noise reduction measures.
Environmental and social considerations:
Water and biological resources
Field studies will map the condition and sensitivity of wetlands, streams, and high-value habitats on and around the site.
Design decisions will aim to avoid or minimize effects on ecological resources and natural water flow.
Where impacts cannot be fully avoided, mitigation measures will be required and monitored.
Environmental and social considerations:
Cultural resources
Cultural heritage field studies are being conducted in active coordination with federally recognized tribes and state authorities.
Historic structures, archaeological sites, traditional cultural areas, and other heritage features may be identified.
Where possible, these features will be avoided entirely; where not, appropriate mitigation will be developed with tribal and community representatives.
Environmental and social considerations:
Flood risk
A dedicated flood assessment study is underway examining stormwater drainage, river behavior, and off-site flood risk.
Project design will be informed by this study to withstand major rainfall events without increasing risk to the community.
Stormwater pollution prevention plans will include engineered drainage, filtration measures, and vegetation buffers to protect the Verdigris River.
Environmental and social considerations:
Waste management
EGA and Century are exploring closed-loop management for key waste streams by identifying local partners.
Process wastewater will go to a new publicly-owned wastewater treatment facility at the Tulsa Port of Inola.
Waste management commitments will be set out in the ESMP and subject to regulatory oversight.
Environmental and social considerations:
Emergency management
Detailed emergency response, spill prevention, and weather resilience plans will be developed as part of the ESIA process.
Plans will address tornadoes, flooding, equipment failures, and
other foreseeable events with clear procedures for workers, residents, and the environment.
Plans will be coordinated with local emergency services and updated throughout the life of the project.
The scoping report has been developed and was offered to the public for review with a 30-day comment period from March 16 to April 15, 2026.
Access the scoping report
Download here
Hard copies are available from the Ingersoll Public Library in Inola, Oklahoma.
A simplified summary report is available to download here.
