A 40-foot sinkhole has opened up at Austin Peay State University’s football stadium in Clarksville, Tenn.

The sinkhole first appeared a couple weeks ago, and was about the size of the desk. Workers were forced to expand it in search for stable bedrock. On Monday the hole was estimated to be 30 by 50 feet wide and 40 feet deep, The Leaf Chronicle reports.

"We have a limestone base underneath us, and limestone is porous and disintegrates from rain over centuries. So it creates a lot of sinkholes, and that's basically what we're experiencing here today," Bill Persinger, a spokesman for APSU told WSMV.

Sinkholes are a common occurrence in the area. Last August, a 5-foot sinkhole opened up near the university’s mathematics center.

"They're actually a main feature of our campus. The center of campus has what we call the bowls, which we've landscaped around as the sinkholes have been remediated years ago,” Persinger said.

Sinkholes have even been added to the university’s budget, Mike Jenkins, superintendent for Nashville-based Bell & Associates Construction said. “You never know to what extent you’re going to run into them, but we know that Montgomery County, and Austin Peay State University specifically, is famous for sinkholes.”

Construction workers plan to fill the hole with several layers of rock separated with concrete and topped off by 2 feet of subgrade asphalt beneath the track and turf. The work should be completed in a week. Smaller sinkholes have opened up in the parking lot area, which will fixed in a separate construction project.

All the work at the stadium, which seats 10,000 people, should be finished before the university football team’s season opener on September 13.