By Kathleen Williams, Office of Public Information

Did you know there is a working limestone mine in Clermont County?

In 2009, Arch Materials, a division of Rogers Group Inc., opened after three years of development. It is located on former farmland on State Route 276 near Hawley Road, and employs 41 people.

The processing plant and sales yard are located on about 50 acres, while 1,000 feet below, a limestone mine operates over 300 acres.

A group of Clermont County employees, including Commissioners David Uible and David Painter, Assistant County Administrator Tom Eigel, and Community & Economic Development Director Andy Kuchta, toured the mine on Tuesday, Aug. 1. We had a fascinating visit, and learned much about the production and use of limestone.

Arch Material’s customers – all within a 50-mile range – are roughly divided into thirds: commercial and industrial; residential; and government. Limestone is one of the primary types of gravel used in asphalt and concrete. When construction is booming, so is limestone mining.

Before we entered the mine – in trucks, which we never got out of – we went through safety training, required by the U.S. Mine Safety and Health Administration. With our hard hats on, we began the tour.

We gradually descended about 1,000 feet down into the mine, where the drilling takes place.

Once a day, at approximately 4:45 p.m., a section of the mine is blasted.

Seismographs on the surface measure the blast, which record levels of these blasts at about one-tenth of legally allowable limits, according to plant manager Greg Black. For comparison purposes, fireworks or a severe thunderstorm give off more of a seismic reaction than do the underground blasts.

In the mine stone is drilled, blasted and then carried away in trucks where it undergoes the first of several crushing operations, this one still underground.

Afterward the ceiling and walls are scaled to remove loose material and then the roof is bolted for additional support.

Back on the surface, the limestone goes through a series of further crushings. Arch Materials produces different grades of rock that meet Ohio Department of Transportation standards – ODOT #2, ODOT #57, etc. – that are used in road construction and pavement projects. The finest material is used as agricultural lime.

“This was a fantastic discovery,” said sales representative Vince Jones of the underground limestone find. “This mine will last several generations, and can expand up and down,” he said.

“We aim to minimize the environmental impact on the area,” Mr. Black stressed. “We keep plant noise and dust to a minimum. The land will eventually be reclaimed and used for other purposes.” For instance, the Mega Cavern in Louisville, Ky., was once an active limestone mine operated by the Rogers Group and now is a popular tourist attraction, offering underground zip lines and tram tours. Louisville Zoo also sits on top of the repurposed mine.

After our tour, we had a much better understanding of limestone mining. Thanks to Arch Materials, this Clermont County product is essential to the transportation infrastructure of Greater Cincinnati – something we all have a stake in.