Pungent, ugly and often-toxic algae is spreading across U.S. waterways, even as the government spends vast sums of money to help farmers reduce fertilizer runoff that helps cause it.
An Associated Press investigation finds harmful algae has become a serious hazard in all 50 states. It's making people sick, killing animals and hammering the economy.
Yet officials rely largely on voluntary farmer cooperation to stem a flood of chemical fertilizers and livestock manure into lakes and streams.
The U.S. Department of Agriculture has spent more than $1.8 billion on the costliest such program since 2009, sharing costs of steps such as improving irrigation and planting off-season cover crops that prevent erosion.
Officials say the practices are working, but acknowledge that a small minority of farmers participate. Critics say regulation and more funding are needed.
