In a draft report released Nov. 5, the Army said stationing a combat aviation brigade at Joint Base Lewis-McChord would have some significant environmental impacts.

The Army also prefers to put a brigade at Colorado's Fort Carson.

"These locations have existing runways and airfields, provide adequate maneuver and airspace for CAB operations, and are equipped with existing training ranges that can support CAB training," the report states. "... The proposed action would allow the Army to maximize integrated air-ground training."

The report says each brigade would have up to 2,700 soldiers and up to 120 helicopters.

"The proposed action will increase the availability of helicopter assets to meet current and future national security requirements and will allow the Army better to organize existing aviation assets to promote more effective training and force management," the report states.

However, the report also says traffic, noise, fish and water quality could be affected at Lewis-McChord and the Yakima Training Center, which could have more wildfires and that its wildlife habitat could suffer.

"The primary environmental issues evaluated include impacts to air quality, soil, airspace, cultural resources, natural resources and noise," the report states.

The Army said it will accept public comment for 45 days on the draft report, called a programmatic environmental impact statement, before issuing the final report. The Army then has 30 days to announce a decision on whether to put the new brigades at Lewis-McChord and Fort Carson.

(Information from an Associated Press report was used in this story.)