10 Most Polluted Lakes in The US

Our waterways, lakes, and oceans are harmed by chemicals, trash, plastics, and other pollutants. British poet W.H. Auden stated, “Thousands have lived without love, but not one without water.” Even though we all understand the necessity of water for existence, we still waste it.

Around 80% of the world’s wastewater is released by people, most of it untreated, polluting waterways, lakes, and oceans. The issue of water pollution is widespread and poses a threat to our health. More people are killed by unsafe water each year than by all other types of crime combined.

This story on the most polluted lakes in the US shows that pollution is an issue worldwide, not just in developing or third-world nations. The ten American waters with the worst pollution levels are discussed below.

10 Most Polluted Lakes in The US

  • Onondaga Lake, New York
  • Florida’s Lake Okeechobee
  • Lake Erie, Michigan
  • Lake Michigan, Wisconsin
  • Oneida Lake, New York
  • Lake Washington, Washington
  • Lake Lanier, Georgia
  • Grand Lake St. Mary’s, Ohio
  • Lake Kinkaid, Illinois
  • Utah Lake, Utah

1. Onondaga Lake, New York

A lake named Onondaga Lake can be found in Central New York, close to the city of Syracuse. It ranks among the most polluted lakes in the globe as well as being one of the most polluted lakes in the nation.

Since the late 1800s, pollution of the lake has been a problem, and ice mining was outlawed as early as 1901. Due to mercury pollution, swimming was prohibited in 1940, and fishing was prohibited in 1970.

Raw sewage was dumped straight into the lake for many years, which led to high nitrogen levels and algae blooms. To regulate sewage pollution, the Syracuse Interceptor Sewage Board was established in 1907.

After many years of work, the lake is now secure for swimming, and Onondaga County officials now claim that a beach could be built along the lake’s shoreline.

We regret to inform you that Onondaga Lake is currently ranked as the second-most polluted lake in the world, trailing only Lake Karachay in Russia. We are happy that improvements are being made that will ideally help to lower its ranking.

Lake Tai in China, Lake Victoria in Africa, Serra Pelada Lake in Brazil, Potpe Lake in Siberia, and Bellandur Lake in India are among the other lakes that make up the list of the most polluted in the globe.

2. Florida’s Lake Okeechobee

Lake Okeechobee, also referred to as Florida’s Inland Sea, is the biggest freshwater lake in the state of Florida. Florida rose to the top of yet another degrading ranking because of its hundreds of thousands of acres of filthy lakes. The state’s waters have long been contaminated by stormwater pollution and algal blooms fed by fertilizer runoff.

Florida has the most lake acres that are too contaminated for swimming or healthy aquatic life, according to a recent survey of water quality across the US. It implies that water can contain high concentrations of bacteria that can make people ill and low concentrations of oxygen or other types of pollution that can harm fish and other aquatic life.

On June 23, 2017, the South Florida Water Management District was granted emergency permission to pump clean water into Lake Okeechobee to protect the wildlife and flora in overtaxed water conservation districts.

3. Lake Erie, Michigan

By surface area, Lake Erie is the fourth-largest lake in North America and the eleventh-largest lake in the globe. It is the southern, shallowest, and smallest of the Great Lakes in terms of capacity. Due to the extensive industrial influence along its coasts, Lake Erie had grown to be the Great Lake with the highest level of pollution by the 1960s.

With 11.6 million people residing in its basin and the watershed being dominated by big towns and extensive agriculture, human activity has a significant effect on it. Factory waste has been dumped into the lake and its streams for many years, including the Cuyahoga River in Cleveland, Ohio, and the Detroit River in Michigan.

Environmental rules have improved water quality significantly since the 1970s and led to the reintroduction of commercially significant fish species like walleye and other biological life. 

4. Lake Michigan, Wisconsin

The second-largest Great Lake by volume (1,180 cu mi; 4,900 cu km) and third-largest by total area (22,404 sq mi) after Lake Superior and Lake Huron are Lake Michigan. (58,030 sq km).

A 1968 story in the Grand Rapids Press discussed the probability and effects of Lake Michigan’s “death,” including how the 30 million people who live in the Great Lakes Basin would have to say farewell to summer cottages, swimming, and fishing.

Rotting algae, dead fish, and motor oil slime would replace clear drinking water and lovely shores. New regulations and laws put forth by the federal government will regulate state industries and the waters that encircle and might pollute the lake, including the Detroit River.

5. Oneida Lake, New York

Oneida Lake is the biggest lake in New York with a total area of 79.8 square miles. Northeast of Syracuse, close to the Great Lakes, is where the lake is. Oneida Lake’s recreational use was hampered by rooted vegetation and algal blooms, which led the state to designate the lake as one of the Clean Water Act’s “impairment waters” in 1998.

Algal blooms in the lake were caused by excess nutrients, especially phosphorus, from urban, agricultural, and suburban runoff. Oneida Lake’s phosphorus loads were effectively decreased by implementing best management practices like barnyard runoff management systems, manure storage systems, and nutrient and sediment control systems.

The New York State Department of Environmental Conservation delisted Oneida Lake because data showed consistent declines in phosphorus levels and indicated that the lake sustains aquatic life and recreational activities.

6. Lake Washington, Washington

A sizable freshwater lagoon called Lagoon Washington is close to Seattle. The second-biggest natural lake in Washington after Lake Chelan, it is the largest lake in King County. Untreated sewage severely polluted Lake Washington before the city of Seattle implemented significant pollution measures.

In the 1950s, Lake Washington received around 20 million gallons per day of sewage effluent from Seattle and the surrounding regions. When the cyanobacterium Oscillatoria rubescens was found in the lake in 1955, it was clear that phosphorus from sewage discharge was being used as fertilizer.

An internationally recognized example of how such efforts can be successful is the successful application of scientific knowledge to public action and the successful rescue of Lake Washington from deterioration. These two events have been the focus of decades of follow-up research by natural and social scientists.

7. Lake Lanier, Georgia

Millions of people who get their drinking water from Georgia’s Lake Lanier may notice an odd flavor or odor when they switch on their faucets. Too many algae raise the expense of treating drinking water and increase users’ water bills.

Additionally, it lessens the water’s ability to hold the air that fish and other aquatic life need to survive. Pollution comes from a variety of sources, including treated sewage discharges, broken septic systems, and improperly disposed of fats, oils, and grease that block sewer lines and cause stormwater runoff from fertilizer used on farms and lawns.

The goal is to improve the water quality, even though it is impractical to physically remove the algae that are already existing in the lake. To handle the problem and adhere to a federal cleanup plan, the Chattahoochee Riverkeeper works in conjunction with local governments, utilities, and other stakeholders.

8. Grand Lake St. Mary’s, Ohio

Grand Lake St. Mary’s, which covers 13,500 acres and is Ohio’s biggest inland lake, has been dubbed the “poster child” for the harmful algal blooms (HAB) problem. HABs started to create issues at the lake in 2009. The state designated the lake, a source of public drinkable water, as distressed in 2011 as a result of significant algal blooms.

Due to nutrient runoff, Grand Lake was once regarded as the most polluted lake in the United States, and for the past ten years, algal microcystin toxin levels in the lake have significantly exceeded allowed limits.

The lake’s water quality is gradually improved by farm practices that reduce fertilizer and manure runoff, yearly dredging of more than 300,000 cubic yards of lake silt, and restoration of water-filtering wetlands.

9. Lake Kinkaid, Illinois

One of the lakes in Illinois with the highest mercury contamination is Lake Kinkaid. Every source of water in Illinois has been contaminated by pollution. The emissions from coal-fired power stations are where the mercury is found. The substance settles in the water after being released into the atmosphere, ultimately ending up in fish.

Fish caught in Illinois should only be consumed in moderation, according to a state-issued fish consumption warning. The short-term goals of the Public Interest Research Group are to lower air pollution by requiring all power facilities to adhere to current emission standards.

In the long run, it will be necessary to reduce dependence on coal, oil, and other polluting energy sources. Renewable energy sources like solar, wind, and others will also be crucial.

10. Utah Lake, Utah

One of the largest natural freshwater lakes in the western United States is Utah Lake. Large yearly algal blooms, an elevated pH, and potential cyanotoxin production are all caused by an excess of nutrients. The lake receives runoff from nonpoint sources, industrial outflows, stormwater discharges, and wastewater treatment facility effluent.

Hypertrophic conditions may be getting worse as a result of the watershed’s rapid urbanization and expansion. Unexpectedly, the “muddiness” of the lake’s water has aided in preserving the fish and water purity.

As a shade umbrella, the suspended silt (mud) blocks out sunlight, thereby decreasing the number of algae that can harm us, our dogs, and the entire lake’s fish population.

There are a few areas where the lake could be improved, even though it has long been a secure spot for people, plants, and animals to play and live.

What are the major pollutants in US lakes?

Despite their size, the Great Lakes are vulnerable to pollution. Less than 1% of the Great Lakes’ annual water capacity is lost through outflows, which is a negligible amount. When pollutants reach lakes, they are kept in the system, and over time, they concentrate. 

  • Pesticides and fertilizers from rural and urban runoff are a few of these pollutants.
  • Elevated amounts of nitrates and phosphates are brought on by sewage seepage into lakes from the groundwater.
  • Heavy metals like lead and mercury, which can enter the food chain, may be present in industrial waste.
  • Sediment that enters lakes as a result of building, urban, or farming activity reduces the clarity and quality of the water and, when it gets trapped in an aquatic organism’s gills, can be fatal.
  • Acid rain and other types of acidic precipitation can reach lakes when pollutants from industrial power plants or automobile exhaust pipes enter the atmosphere.      


Both people and wildlife are at risk from contaminated lakes. Because animals rely on lakes for refuge and hydration, pollution is not only dangerous but potentially fatal to them.

Due to excessive plant development and algal blooms, plants are depleted of oxygen and begin to die. Fish lose their lives as a result of reduced oxygen levels. Algal blooms also make it difficult for fish and other aquatic animals to locate food, which can result in their demise.

Toxins created by the slimy, dense muck of an overabundance of algae blooms progress up the food chain and harm birds and large animals after being consumed by some fish. Eating fish that has been contaminated with chemicals and other toxins can have negative effects on even people.

While the toxins in fish might not make you sick right away, they can build up over time and harm people’s health, particularly children, pregnant or nursing women, and developing fetuses.


Editor at EnvironmentGo! | providenceamaechi0@gmail.com | + posts

A passion-driven environmentalist by heart. Lead content writer at EnvironmentGo.
I strive to educate the public about the environment and its problems.
It has always been about nature, we ought to protect not destroy.

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