WaterToledo’s water alarm harbinger of things to come
This past weekend, officials in Toledo, Ohio urged residents and the several hundred thousand people served by the city’s water utility not to drink tap water after discovering elevated levels of microcystin, a toxin caused by algal blooms, in their water supply. Toledo’s water supply has since returned to normal, but nutrient enrichment and climate change are causing an apparent increase in the toxicity of some algal blooms in freshwater lakes and estuaries around the world, scientists say.
This past weekend, when officials in Toledo, Ohio discovered elevated levels of microcystin, a toxin caused by algal blooms, in their water supply after voluntary tests at the Collins Park Water Treatment Plant, they urged residents and the several hundred thousand people served by the city’s water utility not to drink tap water. Exposure to high levels of microcystin can cause abdominal pain, diarrhea, liver inflammation, and other health problems, some of which are life threatening. Algal blooms are becoming more common in Lake Erie, the water supply for eleven million residents living around the Great Lakes.
The Texas Commission on Environmental Quality (TCEQ) has experienced its own blue-green algae problems at several of the state’s lakes. Surface water data has “not demonstrated levels of algal toxins that show any cause for alarm,” said Terry Clawson, spokesman for TCEQ, but the agency “considers it important to continue screening available data to determine if additional monitoring and evaluations are needed.” According to the Washington Post, Texas state guidelines recommend that officials notify the public of potential swimming hazards if microcystin levels in recreational waters are found to be above twenty parts per billion, but no U.S. state requires testing for toxins caused by algal blooms, and there are no federal or state standards for acceptable levels of the toxins.
Toledo’s water supply has since returned to normal, but nutrient enrichment and climate change are causing “an apparent increase in the toxicity of some algal blooms in freshwater lakes and estuaries around the world,” Oregon State University scientists said last year in the journal Science. Rising temperatures and carbon dioxide concentrations also contribute to the rapid growth of blue-green algae blooms. The Environmental Protection Agency considers blue-green algae to be a “major environmental problem,” but to date, most of the guidelines governing safe microcystin levels in the United States are recommendations from the World Health Organization.
