Greenfield won't be last Iowa town to have drinking water threatened by toxic blue-green algae, environmentalists say

Greenfield is the first city in Iowa to warn residents against drinking its water, fearing contamination from toxic blue-green algae. But it won't be the last, environmentalists say.Dozens of Iowa cities and towns rely on lakes, rivers and reservoirs at risk for cyanobacteria — or blue-green algae — to source their drinking water.Tests on Greenfield's water came back clean for toxins Wednesday, enabling officials to lift a bottled-water order.