Students and experiments evicted from the Civil and Mineral Engineering Building by mold could return early next year.

Repairs on the building are expected to start in July and finish by early 2013, said Raymond Hozalski, a Department of Civil Engineering director.

Parts of the building were cleared out last year due to a mold outbreak caused by water leakage in two underground floors.

Hozalski led the move of lab equipment and environmental experiments sensitive to mold, which affected about 20 students and staff. Most of the equipment was moved to Gortner Laboratory in St. Paul, and some to Shepherd Laboratories in Minneapolis.

Repairs include replacing the building’s roof and other structural repairs to prevent future water damage. The school will also install new waterproofing systems in the building. The current system won’t resolve the leaking problem, said Roberto Ballarini, the head of the department, in a January project planning meeting.

The process to fix the leakage has “run into a couple snags” since the department hasn’t dealt with an issue like this before, said Trevor Miller, a University of Minnesota spokesman.

Meanwhile, the department is striving to keep students, staff and faculty up to date on the cleanup progress, Ballarini said.

Air samples taken last month on the first, sixth and seventh floors of the building were normal. But there was visible fungal growth and water damage in one of the seventh floor rooms.

The building runs 110 feet underground. Its sixth and seventh floors were used to conduct environmental experiments involving water treatment, microbiology and pollution.