Numerous U.S. Environmental Protection Agency studies confirm there is lithium, an alkali metal, in water supplies of many communities. El Paso, Texas, and other cities and regions are testing for the amounts of lithium in their water supplies to help determine if it clearly has detrimental effects on local populations. Professor Paul Westerhoff, the Fulton Schools chair of environmental engineering, says there may be different levels of risk among various communities depending on varying concentrations of lithium. But he says the EPA would need to conclude lithium poses a major threat to human health before requiring water utilities to put stricter limits on its presence.