Backers for the Tukwila arena officially filed paperwork to begin the environmental review of the project on Friday.
According to Seattle’s King 5 News, Ray Bartoszek’s group plans to build a privately financed building 12 miles south of Seattle.
The environmental review would take 6-12 months.
The proposed Northwest Arena would be 195,000 square feet and have an adjacent parking garage.
The Tukwila arena would be in competition with a proposed arena in Seattle’s SoDo district adjacent from Safeco Field where the Mariners play.
Related: Two Seattle arena proposals, now pitted against each other