How Factory Farms Cause Toxic Algal Blooms in the Great Lakes

Published Jun 21, 2024


Food System

Each summer, smelly, dangerous algal blooms erupt on the Great Lakes. One fix to this perennial problem is simple — stop factory farm pollution.

Each summer, smelly, dangerous algal blooms erupt on the Great Lakes. One fix to this perennial problem is simple — stop factory farm pollution.

The Great Lakes provide drinking water to one in ten people in the United States. Millions visit each year to soak up the sun on the beaches, boat on the cool waters, or otherwise enjoy the shore. But every summer, a neon green menace lights up the waters: harmful algal blooms. 

These algal blooms sweep entire shorelines and endanger those who come into contact with them — they’ve even killed pets. Just breathing droplets of contaminated water isn’t safe. That’s because the algae create microcystis, a bacteria that produces the liver toxin microcystin. Rashes, headaches, nausea, and fever are common symptoms of exposure. 

Over the past few years, the United States has seen bigger and more frequent harmful algal blooms. They’re arriving earlier and sticking around later in the season, too. Luckily, we know the most impactful action we can take to avoid them: stopping factory farm pollution.

A Growing Factory Farm Industry Is Making Harmful Algal Blooms Worse

Water pollution and exploitation is an inherent part of the factory farm model. Factory farms concentrate millions of animals into tight spaces — and their waste, too. While smaller farms can manage their manure sustainability, that’s impossible for huge factory farms, which often overapply and oversaturate nearby fields with their waste, which then washes into nearby waterways.

Once in the water, the waste’s high levels of nitrogen and phosphorus feed algae, sparking blooms. In fact, manure from factory farms is a leading source of phosphorus in the Great Lakes.

Global efforts in the 1970s and ‘80s virtually eliminated harmful algae blooms. But unfortunately, they came back in the 1990s, coinciding with the growth of factory farms. The threat of algal blooms is now reaching new heights — since 2011, Lake Erie has experienced several of the worst blooms on record.

This problem is growing because factory farms are growing. In the eight Great Lakes states — Minnesota, Wisconsin, Michigan, Illinois, Indiana, Ohio, Pennsylvania, and New York — factory farms have mushroomed.

For instance, the number of dairy cows confined on mega-dairies in these states have grown nearly four-fold in just twenty years, to over 2 million today. Together, these cows produce 85 billion pounds of manure annually — equivalent to the human sewage created by three New York City metro areas. 

At the same time, harmful algal blooms will continue to grow in size, frequency, and duration as temperatures rise. Unseasonably warm temperatures are already encouraging algal blooms earlier in the summer and well into the fall.

And of course, we can link these rising temperatures to climate change, which factory farms also contribute to. Globally, industrial livestock are responsible for 14.5% of all human-caused greenhouse gas emissions. If they continue to grow, so will their impact on climate. 

Harmful Algal Blooms Threaten People’s Access to Safe, Affordable Water

Some of the most immediate impacts of these blooms is on our ability to enjoy our favorite summer activities. Fishing, boating, and swimming are impossible to do safely with harmful algal blooms in the water. But on top of that, the blooms can harm us in other ways — through our drinking water. 

For example, in 2013, blooms caused a spike in microcystin levels in the drinking water of Carroll Township, Ohio. The municipal supply had to be cut off for two days. A year later, microcystin pollution overwhelmed a water treatment plant in Toledo, Ohio. The City had to issue a days-long “do not drink” order that affected nearly 500,000 people.

This not only endangers residents — it costs them financially. Carroll Township’s microcystin incident forced $125,000 in upgrades to its water systems. Meanwhile, Toledo is spending $80 million to improve its drinking water infrastructure in response to algal blooms.

Many Great Lakes communities in cities like Cleveland, Detroit, Buffalo, and Chicago already face high water costs and shutoffs. Growing financial burdens will hit lower-income communities the hardest.

Current Regulations Are Failing to Protect the Great Lakes

For decades, state and local governments have not held factory farms accountable for their pollution. Notably, the Environmental Protection Agency (EPA) has preserved loopholes for the industry in its enforcement of the Clean Water Act. This allows factory farms to pollute with impunity — and until recently, they haven’t even had to monitor their pollution discharges. 

At the same time, a similar fight is happening at the state level. Take Michigan, for example. In 2020, the state adopted modest, commonsense improvements to its water pollution permit for factory farms. 

Yet, the industry refuses to let go of the unfair benefits they’ve enjoyed for decades. The Farm Bureau and their factory farming cronies have gone into attack mode, dragging the state and environmental advocates through years of litigation and putting much-needed protections on hold.

We cannot let the industry get away with this — communities’ water and health are at stake.  That’s why Food & Water Watch and our allies in Michigan have been fighting back in Michigan administrative courts and before the Michigan Supreme Court.

At the federal level, we’re taking the EPA to court for failing to improve Clean Water Act rules for factory farm pollution. We’re also supporting legislation, like the Farm System Reform Act, to stop the harms of the factory farm model completely.

Every other industry must take responsibility for its waste and work to keep it out of our waterways. Families across the country pay to have our sewage treated. But the factory farm industry has evaded this responsibility and exploited massive loopholes left open by regulators, dumping the costs of its waste onto us.

With the way things are now, families and farmers will continue to pay the price for Big Ag’s profits. Harmful algal blooms, ruined summer plans, and contaminated, expensive water — to stop all these problems, we need to eliminate factory farm pollution.

Help us put an end to factory farms and their pollution. Tell your representative to support the Farm System Reform Act!


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