American Water Works Co. of Voorhees has acquired Environmental Management Corp., a Missouri contractor that operates industrial and municipal water and wastewater systems.

EMC, which has almost 300 employees and 2008 annual revenues of about $50 million, provides contract services for up to 20-year terms and currently has about 55 contracts in the United States and Canada. American did not disclose the price it paid to EMC's owners, The Linde Group, a worldwide gases and engineering company based in Munich. American is the nation's largest investor-owned water company with $2.3 billion in revenue

EMC will operate as a separate business unit of an American subsidiary, American Water Enterprises, until next year when its operations can be integrated with American.