Hawai'i's active-duty Army population of 20,000 could grow by 10 percent between now and 2013, the Army said yesterday.

The "preferred alternative" in an Army environmental study calls for adding 1,700 soldiers at Schofield Barracks and 300 at Fort Shafter.

The additions would primarily be engineers, military police, headquarters units and other support units, the study said. No artillery or aviation units would likely be involved.

The analysis also recommends that 587 soldiers in a Maneuver Enhancement Brigade that had been scheduled for stationing at Schofield be redirected to Fort Drum, N.Y.

The study — a final supplemental programmatic environmental impact statement — also recommends adding soldiers to two Alaska bases: 1,800 soldiers at Fort Richardson and 425 at Fort Wainwright.

The study analyzed locations capable of supporting mission requirements across the Pacific Ocean and from the Arctic to the Antarctic.

The Army is expected to make a final decision in about a month, after commanders review the environmental report.

Most of the Army's growth will be in Texas, Georgia and Colorado, states that are getting new combat brigades.