Public Comment Period on Intent to Make a Determination
Construction of the Arctic Over-the-Horizon Radar (A-OTHR) Capability at 0 Thistle Trail, Kirkfield, Ontario

July 17, 2025 — The Department of National Defence must decide whether the proposed project is likely to cause significant adverse environmental effects.

To help inform this decision, the Department of National Defence is inviting comments from the public on the project and its potential effects on the environment. All comments received will be considered public. For more information, individuals should consult the Privacy Notice on the Registry website.

Written comments must be submitted by August 5, 2025 to:
Irv Marucelj, Project Manager, NORAD Modernization Infrastructure Project Delivery
Mailing Address:  NDHQ - 101 Colonel By Dr, Ottawa
Ontario, Canada, K1A 0K2
E-mail:  NORAD_CI-IC_NORAD@forces.gc.ca

The Proposed Project

The Department of National Defence (DND) is proposing a project. As part of Canada's North American Aerospace Defense Command (NORAD) modernization plan, DND is investing in a new Northern Approaches Surveillance System (NASS) to significantly expand NORAD and the Canadian Armed Forces' (CAF) situational awareness of objects approaching and entering Canadian airspace from the North. NASS will include the Arctic Over-the-Horizon Radar (A-OTHR) system that will provide early warning radar coverage and threat tracking.

The A-OTHR capability will be located in Southern Ontario and will extend NORAD and the CAF's situational awareness into the Canadian North and the North Atlantic.

Development at the site will focus on installation of transmitting antennas. Land preparation will include flattening of the land and removal of any obstructions that would impede the radar's signal, including potential clearing of forested areas or filling of wetlands.

While specific infrastructure needs are being finalized, the A-OTHR system will require supporting infrastructure at each site:

• Fully equipped operational building;
• Physical security features;
• Maintenance and storage facility;
• Access road and parking; and
• Utilities (power, water, wastewater, stormwater, communications).

Additional information is available on the Department of National Defence website.