Lakes, reservoirs, rivers and streams are critical sources of drinking water for millions of Americans. They also provide recreational opportunities and wildlife habitat.
Now many of these water bodies are threatened by a growing phenomenon known as algae blooms, fueled largely by polluted runoff from farms and exacerbated by climate change. Algae blooms wreak havoc on ecosystems, and the cyanobacteria that make up these outbreaks sometimes produce poisonous byproducts called cyanotoxins. Ingestion of or even just exposure to these toxins has been associated with many human health issues, ranging from diarrhea to cancer, as well as with pet and wildlife deaths.
Currently, no government agency publicly tracks toxic algae outbreaks nationally. To fill this gap and help policymakers and consumers understand and quantify the impact of toxic algae blooms on drinking water, recreation, public health and the environment, EWG is monitoring and mapping all related news reports across the U.S. since 2010.
If you see algae that is bluish-green or looks like pea soup in a lake or other water body, contact the local health department to let them know and have it tested for toxins. You can also reach out to local media to try to get coverage of the issue.
Check out our map here.
View photos of algae blooms here.
With peak toxic algae bloom season underway, the Environmental Working Group is releasing an updated map of all algae outbreaks reported in the U.S. since 2010. In coming months, the map will be updated weekly, providing comprehensive tracking of this growing nationwide hazard.Read More
Private wells across Iowa are contaminated with unsafe levels of two agricultural contaminants, according to an investigation by the Environmental Working Group and the Iowa Environmental Council.Read More
Across America, outbreaks of toxic algae, triggered by polluted farm runoff, are increasing in frequency and severity, fouling drinking water with dangerous toxins. In 2014, an algae outbreak in Lake Erie contaminated the tap water for 500,000 people in and around Toledo, Ohio, rendering it unsafe to drink for three days.Read More
The Maumee River, overloaded with fertilizer and manure, is the single largest source of the phosphorus that triggers blooms of toxic algae in Lake Erie. Over half of the manure in the Maumee River watershed comes from an exploding number of unregulated factory farms, a new EWG and Environmental Law & Policy Center investigation reveals.Read More
Outbreaks of toxic algae in U.S. waterways usually happen in warmer months. But in a sign that the problem is growing worse, algae blooms were reported in December in Michigan and Washington state, with another reported in Florida during the first days of spring.Read More
Outbreaks of potentially toxic algae in U.S. lakes, rivers and other waterways rose by an additional 40 percent this year compared to 2017, according to EWG’s tracking of news reports.Read More
This summer, EWG is tracking outbreaks of potentially toxic algae across the U.S. We have been startled to find that these outbreaks are erupting everywhere: from the East Coast to the West Coast, from the Great Lakes to the Gulf of Mexico.Read More
Outbreaks of potentially toxic algae in U.S. lakes, rivers, streams and even the Gulf of Mexico continue to rise sharply this summer, according to EWG’s ongoing tracking of algae outbreaks.Read More
An unprecedented environmental catastrophe is striking Florida’s storied beaches, lakes and rivers this summer. Outbreaks of three separate strains of harmful algae are killing fish and other marine animals, threatening public health and devastating recreation and tourism.Read More
Outbreaks of potentially toxic algae are rising sharply this summer in lakes, rivers and streams in the U.S., according to EWG’s ongoing tracking of algae outbreaks.Read More
Millions of people could be exposed to potentially toxic algae blooms this July Fourth holiday.Read More
Across the U.S., there is a growing epidemic of harmful algal blooms – also known as blue-green algae – polluting lakes, rivers and swimming holes, EWG reported this month.Read More
In 2010, there were just three reports of toxic blooms in the U.S. In 2015, there were 15, including the largest to date in Lake Erie, although the bacteria did not get into Toledo’s drinking water. In 2016, there were 51, including a huge bloom in Florida that prompted the state to declare an emergency in four counties on the Atlantic Coast. Last year, 169 blooms were reported. And in March, Ohio Gov. John Kasich declared the open waters of western Lake Erie “impaired for recreation” – an unprecedented designation that under the federal Clean Water Act will require the development and enforcement of plans to reduce toxic blooms.Read More
In 2014, Toledo was the first U.S. city where a toxic algal bloom made tap water unsafe to drink. But it may not be last, says a new report by the Environmental Working Group.Read More
Across the U.S., a growing epidemic of toxic algal blooms is polluting lakes and other waterways, according to a new report by the Environmental Working Group.Read More
What comes to mind when you think of the Florida coast? Sandy beaches, sunshine, warm water and … toxic algal blooms?Read More
Ripped from the pages of an obscure science fiction novel, millions run screaming from the threat of a toxic algal bloom blanketing almost 650 miles of the Ohio River. Regrettably, this story isn’t made up. Officials in the Ohio River basin are scrambling to deal with poisonous slime that may compromise the safety of drinking water, suffocate aquatic life and halt recreational activity for much of the region.