Here’s your chance to weigh in on Wolfspeed’s air quality permit

Raleigh, NC – The N.C. Department of Environmental Quality’s Division of Air Quality (DAQ) is seeking public comment on a draft air quality permit for Wolfspeed, Inc. – Siler City Factory.

The current address for the Wolfspeed project is 20436 US Highway 64 W., west of Siler City, at the Chatham County manufacturing megasite. This address is in between Stockyard Road and J.C. Teague Road (Fig. 1). Once constructed, the future factory address will be 1000 Carolina Core Parkway, Siler City

Comments will be accepted until May 13, 2023.

The air quality permit would allow Wolfspeed to construct and operate a new semiconductor manufacturing plant in Chatham County. The facility will be considered a major source under Title V of the Clean Air Act because potential emissions of nitrogen oxides (NOx) will be 113 tons per year, which is above the 100 tons per year major source threshold.

The draft permit would require the facility to use a gas scrubber system to control emissions of volatile organic compounds, hazardous air pollutants and toxic air pollutants. A gas abatement system and particulate matter collection devices will control emissions of additional pollutants.

Air dispersion modeling reviewed by DAQ shows the facility’s emissions will comply with applicable standards. The draft permit includes conditions that ensure ambient levels of all pollutants beyond the facility’s fence line comply with emission standards, including applicable health-based standards. The facility would also be subject to recordkeeping requirements and regular inspections.

Copies of the public notice, draft permit, draft permit review, draft environmental justice report, permit application, and a one-page project fact sheet are available online.

Comments or requests for a public hearing will be accepted until May 13, 2023, at 5 p.m. Comments can be emailed to with “Wolfspeed.22A” in the subject line, or left via voice mail by calling 919-707-8714. Comments can also be mailed to:

NCDEQ Division of Air Quality
1641 Mail Service Center
Raleigh, North Carolina 27699-1641

The Division will consider all public comments before making a final decision on the proposed permit.