Wastewater AP file.JPG Aeration basins are seen in operation at the Wilmington Wastewater Treatment Plant in Wilmington, Del. American Water Works, the largest publicly traded U.S. water company, sees an opportunity in treating wastewater. (AP file photo) American Water Works Co., the largest publicly traded water company in the U.S., sees its growth being spurred by expanding wastewater services as systems age and municipalities juggle competing demands for funds. "You'll see more of our growth, probably an acceleration of it, being driven by wastewater," Chief Executive Officer Jeffry Sterba said in a phone interview yesterday. He's also in talks to treat the resulting waste from the vast volumes of water required by shale explorers for hydraulic fracturing. Handling wastewater for cities and other utilities accounts for about 3 percent of the Voorhees, New Jersey-based company's regulated sales, Sterba said.