An Indiana DNR Division of Reclamation (DOR) project in southwest Indiana will receive the highest regional award the federal Office of Surface Mining Reclamation and Enforcement (OSMRE) issues annually.

The award is for the Buttermilk Highwalls project in Pike County. The project addressed public safety and environmental concerns left by the Ayrshire #7400 mine that operated from 1953-1955 in what is now a section of Sugar Ridge Fish & Wildlife Area. The project included two highwalls and an acidic mine pit lake with poor water quality. Ranging between 15 and 38 feet high, with a combined length of 1,615 feet, the steep and unstable highwalls were a danger to Sugar Ridge FWA visitors.

To address the safety hazard, the DOR backfilled the highwalls to a safer 4:1 slope using geomorphic landscape design, which mimics natural topography to better withstand erosion. The highwall backfills required the DOR to eliminate the acidic mine pit lake and reconfigure other lakes and landforms at the site.

In addition to making the site safer, the project helped mitigate a complex water management problem caused by the hydrological connection of surface mine pit lakes in the area through underground mine workings between the lakes. To address this situation, the DOR coordinated engineering designs for multiple projects.

First, the DOR reclaimed one of the affected mine pit lakes and its adjacent highwall, Pigeon Pit, as part of the Sugar Ridge #2 project completed in 2016. The Pigeon Pit project was recognized for outstanding reclamation from OSMRE with the 2017 Mid-Continent Regional Award.

The Buttermilk Highwalls project added to that effort by adjusting the elevation of Whitney Pit, one of two mine pit lakes originally at the site. As a result, directional movement of water between the mine pit lakes was reduced, which inhibits the formation of subsidences in the mine workings between the lakes, thus mitigating a potential mine-sourced safety hazard in the area.

The project was designed by engineers in the DOR’s Abandoned Mine Land (AML) program. Project construction was completed by Aigner Construction, Inc., of Boonville.

“Our Reclamation engineering and project management staff did a great job of planning and executing these projects for the long term benefit of the public and environment,” said DNR director Dan Bortner. “The collaboration of staff to produce nationally recognized reclamation of pre-law mining areas is a great example of DNR teamwork.”

Indiana was among five winners of the 2020 AML Reclamation Awards. A panel of judges composed of directors of state and tribal reclamation programs and OSMRE managers determined the recipients. Since 1982, the AML program in Indiana has restored more than 1,100 AML construction sites that encompass approximately 10,000 acres of pre-law abandoned coal mines and related impacts.

OSMRE will present the award as part of a virtual presentation on Sept. 21.

The DOR administers the surface coal mining laws for Indiana. DOR’s Inspection & Enforcement Section permits and inspects active coal mines. The AML program is responsible for eliminating threats to the public and environment remaining from coal mining activity prior to the enactment of current law. All activities are funded through fees collected from active coal mining production. For more information, call the division field office in Jasonville at 812-665-2207; or toll-free if calling inside Indiana at 1-800-772-6463.