Toxic Algae is a Problem for Drinking Water
Toxic algae has made Iowa’s Des Moines River “essentially unusable” for drinking water without intensive — and expensive — treatment, Des Moines Water Works leaders said. To get the river up to drinking water standards requires huge effort and costs to remove the toxin that comes from blue-green algae, called microcystin. As one of the two largest water sources treated for the city’s tap water, there is genuine concern about Des Moines River contamination, especially in the summertime when the algal bloom growth spikes.
The contamination comes from farm runoff that carries large quantities of fertilizer and manure that contains nutrients, like nitrates, that help the toxic algal flourish. Under certain conditions, the blue-green algae can produce microcystin, which can cause skin irritation, gastrointestinal issues and even liver damage. These toxins can also be harmful to animals, and has been known to kill dogs who drink contaminated water.
To combat the algae crisis, Des Moines Water Works has discussed construction of a shallow-well to avoid the problem of toxins and and nitrates, but it would cost tens of millions of dollars and higher water rates for city water users. The best solution is to stop pollution at the source, meaning the reduction of runoff from farm fields and CAFO manure lagoons. The farm lobby and public officials largely oppose strict runoff mitigation requirements on farmers because they think such rules are too burdensome. The reality is that drinking water is being polluted and the people who caused it are not on the hook for cleaning it up.
Check out our infographic series on toxic algae (aka harmful algal blooms). Get the deep context about their growing threat, what causes them, their potential toxic hazards and hot spots around the United States. Go to FoodPrint to learn more about how industrial agriculture can affect our water.