The NC Department of Environmental Quality’s Division of Air Quality is issuing Carolina Lithium, a proposed lithium mining and processing facility in Gaston County, an air quality permit that incorporates feedback received during the public comment period.
Carolina Lithium, owned and operated by Piedmont Lithium Carolinas Inc., will be classified as a major-source Title V facility because its operations have the potential to emit air pollutants above certain thresholds. The permit allows emissions associated with mining, crushing and handling of spodumene ore, a key source of lithium for batteries, as well as processing and concentrating the ore into lithium hydroxide at on-site plants.
DEQ held a 42-day comment period with a public hearing on Oct. 13 to solicit comments on a draft of the permit. In response to public comments, the final permit restricts the facility’s ability to process spodumene ore mined off-site and adds a new requirement that the mine sample more of its ore to determine its elemental makeup before it can begin operating the processing plants.
Also in response to comments, DEQ reviewed the company’s recent land sales and confirmed that the facility still has legal access to all the parcels included in the modeling analysis. The final permit prohibits Carolina Lithium from modifying its property boundary from what was included in that model.
The facility’s potential emissions of particle pollution, nitrogen oxides and carbon monoxide are each above the threshold that triggered a Prevention of Significant Deterioration review to ensure that the emissions will not cause a violation of federal ambient air quality standards. These federal standards are protective of public health, including the health of sensitive groups like children and older adults, as well as public welfare, including protection against decreased visibility and damage to animals, crops, vegetation and buildings.
DEQ’s review found that the emissions, controlled by the best available control technology required in the draft permit, are expected to maintain the state’s compliance with federal air quality standards, including the more stringent fine particle pollution standard set by the Environmental Protection Agency in 2024.
Carolina Lithium will be required to control its fugitive dust to prevent it from migrating offsite.
The facility’s emissions of hazardous air pollutants will be capped to minor source levels, meaning the facility must keep hazardous air pollutant emissions below 10 tons per year for any single pollutant and below 25 tons per year for all pollutants combined. Remaining below these limits triggers a different set of federal standards designed for lower-emitting facilities.
The facility will be subject to multiple federal performance standards. Air dispersion modeling determined that emissions of toxic air pollutants are not expected to violate health-based air quality levels.
Carolina Lithium received a mining permit from DEQ’s Division of Energy, Mineral, and Land Resources in 2024 to operate the 1,548-acre mine, which includes additional restrictions and conditions on its operation. The final air quality permit also requires the facility to comply with any applicable local zoning regulations before it can begin construction and operation.
Copies of the final permitting documents, including the public notice, final permit, final permit review, permit application and a one-page fact sheet are available online.
Additional information about air quality permitting is available online in our FAQ.