The former psychiatric hospital on Seven Mile Road has proven to be a demolition challenge because of harmful material on the property.
On top of finding asbestos in the buildings, there are also large quantities of environmentally sensitive material.
"There are hundreds of barrels out there," said Robert Nix, Northville Township supervisor, at a meeting Wednesday in Township Hall.
The barrels, filled with unknown substances, must be tested before they can be removed. Additionally, the barrels will cost more to remove because they are not empty. Nix said they should be cleared in the next several weeks.
The township removed two buildings in August on the property and allocated about $400,000 to spend on the project, while getting other funds from grants, he said.
"It looks like it will be under budget," he said.
The township is in the process of securing grants for the rest of the clean-up and demolition, which Nix said could cost $9 to $15 million.