Covanta, a provider of sustainable waste and energy solutions based in Morristown, New Jersey, has announced the additions of Danielle Pletka and Michael W. Ranger to its board of directors.

The company says Pletka is an expert in international affairs and national security matters, serving as senior vice president of foreign and defense policy studies at the American Enterprise Institute (AEI), a leading public policy research organization. Prior to joining AEI, she served as a longtime senior staff member for the United States Senate Committee on Foreign Relations.

Ranger is co-founder and senior managing director of Diamond Castle Holdings LLC, a private equity investment firm focusing on energy and power, healthcare, financial services and other diversified industries. He has more than 30 years of experience in the energy and power sector.

"We are delighted to enhance the depth of our board with these highly accomplished individuals," says Sam Zell, Covanta’s chairman. "I am confident that Danielle’s global policy expertise and Michael’s industry perspective and strategic insights will provide important contributions to our efforts to grow the business and create long-term value for our shareholders."