It's been a big problem for years, but now the number of sinkholes along South Sprigg Street has grown to more than 30, prompting Cape Girardeau officials to indefinitely close a crumbled section of roadway.

And if a solution of some sort isn't found, the street closure could be permanent.

"That would be a worst-case scenario," Mayor Harry Rediger said Thursday. "But it's on the horizon, there's no question. The problem is if we fix one, another one pops up somewhere else. It's just a huge problem."

The sinkholes have plagued the South Sprigg Street area since 2007, when the first few were noticed south of the city's wastewater treatment plant. Earlier this year, the number of sinkholes -- the bottoms of some have not been reached -- stood at 18. The flooding this spring caused that number to grow by 15 to 33 in the last two months, assistant city manager Ken Eftink said. That number included two in Sprigg Street driving lanes near a bridge over La Croix Creek, prompting the city to close the street there April 29, he said.

Rising river water has exacerbated the problem, Eftink said. Water makes its way through the ground's subsurface into Buzzi Unicem's quarry. The water erodes the soil and, as the water recedes, new sinkholes are created or existing ones are made worse, Eftink said.

"It's like Swiss cheese out there," Eftink said. "The city has spent tens of thousands of dollars to fix it, and nothing's really worked."

The city and Buzzi Unicem have tried filling in the sinkholes, using rock and concrete, Eftink said, but they either reappear or occur in other places. Covering the sinkholes with concrete also hasn't worked, he said.

The state Department of Natural Resources is going to take a look at the problem in the next two weeks, he said. City officials have also met with the U.S. Army Corps of Engineers, the U.S. Geological Survey and representatives from U.S. Rep. Jo Ann Emerson and U.S. Sen. Roy Blunt.

Still, with no solution in sight and several costly failed attempts at filling in the sinkholes, Eftink said it was decided Thursday to close the street indefinitely.

"Right now, we don't know that we have an engineering solution," Eftink said. "We don't want to spend more money unless we know that it won't fail in the future."

Only three of the sinkholes are on city property, while the rest are on land owned by Buzzi Unicem, Hunze Dairy Farm and Southeast Missouri Stone. The sinkholes have caused problems for all of those businesses, as well as for Ameren Missouri, which operates a six-inch, high-pressure gas line in the area, Eftink said.

The Burlington Northern Sante Fe Railroad is also mindful of the sinkholes, with at least one situated near its tracks, said Tom Abkemeier, a consultant for the company looking at the problem. The railroad has set up settlement monitors that are hooked into the signal system to indicate land shifts, Abkemeier said.

"They would know to stop the train before they ever got into the area," he said. "At this point in time, this has been a long-term problem and there is no solution."

Relocating the tracks have not been discussed, Abkemeier said, but added the company is exploring alternatives for the railroad to protect the track.

Buzzi Unicem has seen production of its cement plant interrupted in the past because of the sinkholes. That has city officials concerned about the possibility of the Italy-based company moving away from Cape Girardeau.

"We are extremely concerned about that," Eftink said. "That's 175 good jobs, plus all the spinoff that company does to our economy. That would have a significant impact on our community, and no one wants to see that."

Executives with Buzzi, which operates seven other cement plants in the U.S., could not be reached for comment.

The sinkholes have been problematic for the city in other regards as well, public works director Tim Gramling said. The city had to change plans to expand its wastewater treatment plant and instead build a new one in another spot because of the sinkholes.

"It's been a huge headache for us," Gramling said. "I haven't seen anything like this before."

smoyers@semissourian.com

388-3642

Pertinent address:

South Sprigg Street, Cape Girardeau, MO