Tom Niemann submitted the plan in response to a letter from the Office of the Maine Attorney General that threatened a lawsuit if his North Carolina firm, Niemann Capital, didn’t take steps to prevent further damage to the Augusta property by Oct. 1.

State officials agreed to extend that deadline by three weeks, and Niemann told the Kennebec Journal he submitted his plan for the complex on Oct. 22 — the last day of the deadline.

A spokeswoman for the attorney general said Niemann’s plan is under review and had no further information.

The Civil War-era arsenal is a National Historic Landmark.