Deadly Toxins in Water Supply a 'Wake-Up Call' for Local U.S. Authorities

BY EMMA PENROD

The swimmers and kayakers of Oregon are no strangers to algae. In recent years, warnings of infestations in ponds and lakes have become routine. When an early-summer algal bloom developed on Detroit Lake near Salem this May, state and city officials knew exactly what tests to run and advisories to issue.

But city leaders hadn’t anticipated a threat to drinking water. Detroit Lake drains into the North Santiam River, and from there, water runs into the municipal system. On May 31, a few days after the algae was first detected in the system, Salem toxicologists found potentially deadly toxins in the water supply. That same day, the city warned its nearly 200,000 residents that tap water was off-­limits for children under the age of 6, people with existing liver or kidney conditions, pregnant and nursing women, the elderly and pets. The advisory remained in place for more than a month.

Because of the lack of data, experts don’t know for certain whether toxic algae outbreaks are increasing in frequency or simply being reported more often. But warmer temperatures do encourage the growth of algae and algal blooms, and that can come with a potentially deadly threat.

Most algae are harmless, but certain species of the blue-green variety, also called cyanobacteria, produce toxins strong enough to poison large mammals, including humans, with potentially fatal consequences. In 2001, the EPA and the Water Research Foundation surveyed 45 drinking water sources in the U.S. and Canada. Four in five, they found, were contaminated with microcystin, which attacks the liver and kidneys. Although most people make full recoveries, life can become pretty unpleasant, and the symptoms—fever, nausea and diarrhea—can be confused with food poisoning.