US: Californian floods move harmful microbes, bad news for farmers

The flood waters that repeatedly breach the banks of the Californian Salinas River and ripple through nearby agricultural fields leave a clear path of destruction. Waves of water scour into farmland and wash away fertile topsoil — up to several feet deep — downstream and out to sea. But there are hidden problems that linger in the soil long after the flood waters have subsided — tiny organisms that can ruin crops and others that can make vegetable-lovers very sick.

Tiny pollutants threaten public health
Raging flood waters wash over everything in their path: wild animal feces, manure piles, oil-coated roads, and overflow septic systems. This water smears bacteria, toxic metals, oil, sewage and other microorganisms over fields and crops. If these pollutants stick to leafy greens — which usually aren’t cooked before eaten — they can make consumers ill. Bacteria, such as E. coli, when eaten by people can cause bloody diarrhea, destroy kidneys, and even lead to death.

There is no way to clean the bacteria-laced produce well enough to sell it to the public. Farmers have no option but to abandon crops submerged under flood water, a move that’s recommended by the California’s Leafy Greens Marketing Agreement and the U.S. Food and Drug Administration.

The Leafy Greens Marketing Agreement was drawn up in response to the 2006 E. coli outbreak carried on spinach that the Centers for Disease Control tracked back to a San Benito County ranch. The contaminated greens sickened more than 200 people in 26 states and Canada and led to five deaths.

During the outbreak, the FDA warned people not to eat fresh spinach and Central Coast shippers threw away tons of the recalled product.

“We try to make sure everyone remembers the costs to the industry were not just economic,” said Scott Horsfall, chief executive officer of the Leafy Greens Marketing Agreement. “There was a tragic human cost; that’s why we’ve got to continue to do everything we can do to keep it from happening again.”

In an effort to protect food safety, the agreement sets growing practices for leafy greens, including sanitation, fertilizer use, water quality and how farmers can use their fields after a flood.

Joining the program is voluntary but “99 percent of leafy greens grown in the state are LGMA certified,” said Mike Villaneva, technical director at LGMA. “People won’t buy your crop if it isn’t.”

Retailers won’t take a chance on produce affected by floods, which could be contaminated with harmful bacteria, including E. coli or salmonella.

Under the guidelines, produce touched by the flood or within 30 feet of the invading water’s edge cannot be sold.

Right after a flood, a large number of bacteria can invade the soil but most dry out and quickly die off after roughly 30 days, said Trevor Suslow, researcher at the University of California, Davis.

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