David J. Singleton

O-N Minerals Co manufactures and supplies limestone. Its products include limestone derivatives, chemical limestone, and construction aggregates. The company was founded in 1992 and is headquartered in Cleveland, OH.

Arup Group Ltd. provides engineering, design, planning and project management consulting services. The company has offices across Europe, North America, Africa, Australasia and South East Asia. It offers building design, economics and planning, infrastructure design, management consulting and specialist technical services. The firm was founded by Ove Arup in 1946 and is headquartered in London, the United Kingdom.

Part of Brickworks Ltd., Global Clay Products is a company that manufactures and supplies construction bricks, paving bricks, and other clay brick products. The company is based in Marseilles, IL. Global Clay Products was acquired by Glen-Gery Corp., a SUB of Brickworks Ltd. from Royal Bank of Canada on December 31, 2001 for $21.20 million.

Polaris Materials Corp. engages in the supply of construction aggregates. Its products include fine sand, crushed rock products, and concrete aggregates. The company was founded by Marco Antonio Romero and Roman Shklanka on May 14, 1999 and is headquartered in Vancouver, Canada.

National Stone, Sand & Gravel Association is a non profit organization which advocates for the aggregates industry. It advances public policies that protect and expand the safe, environmentally responsible use of aggregates that build America’s infrastructure and economy. The company is headquartered in Alexandria, VA.

Part of Vulcan Materials Co., Eagle Rock Aggregates, Inc. is a Canadian company that wholesales construction materials. The company is based in Vernon, Canada. William B. Terry has been the CEO of the company since 2006.