Lake Michigan's Pollution Crisis: A Deepening Ecological Threat

Lake Michigan is the second-largest of the Great Lakes and the only one located entirely within the US. It is a source of drinking water for Chicago and supports activities such as fishing, tourism and transportation. However, Lake Michigan is facing a growing environmental crisis due to pollution. The primary sources of pollution are plastic, agricultural runoff and toxic chemicals from industrial plants. According to the Rochester Institute of Technology, 22 million pounds of plastic are dumped into the Great Lakes annually, with Lake Michigan being the most polluted lake, receiving almost half of this plastic. This plastic breaks down into microplastics, which can pass through water filtration systems and be consumed by humans, potentially impacting their health. In addition to plastic pollution, agricultural runoff, including fertiliser, can cause harmful algal blooms, which can make water toxic to fish, wildlife and people. Finally, toxic chemicals from industrial plants have historically contaminated Lake Michigan, with sediment releasing carcinogenic and neurotoxic heavy metals, PAHs, PCBs and other compounds into the water and wildlife.

Microplastics in the water supply

Lake Michigan is the largest body of fresh water in the United States, providing drinking water for Chicago and contributing to fishing, tourism, and transportation. However, it is facing a growing pollution problem, with plastic being the major contributor.

Microplastics are plastic particles under 5mm in size, which can be intentionally manufactured or formed from the degradation of larger plastics. They are often found in waterways like the Great Lakes, threatening the communities that rely on them for food, water, and income.

A recent study from the University of Toronto found that 90% of water samples taken from the Great Lakes over the past 10 years are contaminated with microplastics at levels unsafe for wildlife. These microplastics can come from various sources, including city water runoff, heavy winds, and rain storms. They are challenging to regulate due to their small size and diverse sources.

Microplastics have been detected in human blood, organs, and breast milk, but the exact health risks are still unknown. However, their impact on wildlife has been well-documented. Studies have shown that animals exposed to microplastics may experience developmental delays, reduced mental processing, infertility, and weakened immune systems.

Microplastics can enter the food web through mussels, algae, invertebrates, and birds, and they can also be ingested by fish. Contaminated fish and other lake-dwelling animals are consumed by people in the Great Lakes region and beyond, with potential unknown health consequences.

To tackle this issue, cities like Chicago have started installing filters on storm drains and sewage systems to catch macro and microplastics. However, much of the microplastic pollution in the Great Lakes comes from airborne particles, making these filters less effective. Experts emphasize the need to reduce plastic consumption and production to curb the flow of microplastics into water bodies like Lake Michigan.

Fertilizer runoff from farming

One of the main consequences of fertilizer runoff is the growth of harmful algal blooms. Algae thrive on the excess nutrients, leading to rapid and uncontrolled growth. These algal blooms can make the water toxic to fish, wildlife, and even people. When the algae die and decompose, they consume oxygen in the water, creating "dead zones" where there is not enough oxygen for marine life to survive. This has severe impacts on the fish population in Lake Michigan, disrupting the food web and affecting recreational fishing, which is an important economic activity in the region.

In addition to the environmental impacts, fertilizer runoff also has economic consequences. The presence of harmful algal blooms and dead zones can deter tourists, affecting the local economy. Additionally, communities surrounding the lake may incur higher costs for drinking water treatment to ensure safe and clean water for their residents.

To address the issue of fertilizer runoff, some farmers have implemented voluntary changes to reduce the amount of phosphorus entering the lake. For example, farmer Jay Williams has adopted practices such as planting cover crops and using precision fertilizer application techniques to minimize runoff and unlock soil nutrients. However, not enough farmers are currently pursuing these sustainable practices. Environmental regulators and advocates are calling for mandatory regulations to reduce nutrient pollution and protect the lake's ecosystem and drinking water sources.

Overall, fertilizer runoff from farming activities has a significant impact on Lake Michigan, affecting both the environment and the local communities that depend on it. Addressing this issue through a combination of voluntary efforts and mandatory regulations is crucial to restoring and preserving the health of the lake.

Industrial waste

By the 1960s, the waterways were heavily polluted, with toxic waste settling into the sediment. This waste included chemicals, toxic pollutants, pesticides, and heavy metals, which entered the lakes through thousands of factory discharge pipes and sewage plants, as well as from dumping and disposal sites, smokestacks, and runoff from cities and farmland.

Lake Erie, in particular, suffered from heavy industrial pollution along its shores, with factories dumping chemical pollutants into the lake and the waterways flowing into it, such as the Cuyahoga and Detroit Rivers. The Grand Calumet River, which empties into Lake Michigan, was also heavily contaminated by steel mills, oil refineries, pharmaceutical manufacturers, and other industries.

The pollution from industrial waste had severe ecological and social consequences. Toxins distributed via the Great Lakes, even in small concentrations, are capable of causing cancer, birth defects, and damage to the nervous and immune systems. Pollutants can resist breakdown and persist in the ecological food chain for years, accumulating in fatty tissue and increasing in concentration as they move through the food web.

In addition, industrial waste disrupted the ecosystem of Lake Erie, causing an increase in algae growth due to the over-enrichment of the water. This reduced oxygen levels in the water, leading to the deterioration of fish species and negatively impacting recreational fishing, fish markets, and related businesses.

To address the issue of industrial waste, the International Joint Commission (IJC) was formed, uniting Canada and the United States in their efforts to resolve disputes related to the waters along their shared border. The U.S. government also implemented new restrictions and laws to control state industries and waters that could potentially pollute Lake Michigan, such as the Detroit River.

Cities surrounding Lake Erie built sewage plants, and industries installed water filters to mitigate the damage and slow down the rate of deterioration. However, these measures did not reverse the harm already done to the lakes.

Today, while new types of pollution emerge, the cleanup of toxic industrial waste continues, with organizations like the Alliance for the Great Lakes pushing for action and advocating for the protection and restoration of the Great Lakes ecosystem.

Sewage and wastewater

One of the key concerns regarding sewage and wastewater is the impact on water quality. During heavy rainstorms, the capacity of treatment plants can be exceeded, leading to raw sewage bypassing the treatment process and ending up in the lake. This issue is exacerbated by combined sewer systems, where stormwater and wastewater are carried in the same pipes. When the volume of water surpasses the system's capacity, untreated sewage is discharged directly into the lake, along with bacteria, chemicals, and other pollutants. This not only poses risks to aquatic life but also has implications for human health.

In addition to the direct discharge of sewage, wastewater from industrial processes has also contributed to the pollution of Lake Michigan. Industrial waste, including toxic chemicals, heavy metals, and pollutants from factories, mills, and refineries, has found its way into the lake. These contaminants accumulate in the lake's sediment, releasing carcinogenic and neurotoxic substances into the water and affecting both wildlife and humans.

To address these issues, efforts have been made to improve sewage treatment infrastructure and separate stormwater and wastewater systems. The separation of sewer systems has been successful in cities like Grand Rapids, which invested $400 million to stop the flow of raw sewage into the Grand River and, ultimately, Lake Michigan. Additionally, initiatives such as the Great Lakes Water Quality Agreement between the United States and Canada aim to restore and maintain the integrity of the Great Lakes ecosystem.

However, despite these efforts, challenges remain. Aging infrastructure, insufficient maintenance, and the need for updated regulations and enforcement continue to impact the effectiveness of sewage and wastewater management. As a result, Lake Michigan continues to face the consequences of pollution, highlighting the ongoing need for comprehensive solutions to protect this vital water resource.

Invasive species

Asian carp, for example, are invasive fish that grow fast and jump high. They have invaded many parts of the Mississippi River Watershed, wiping out native species. Scientists fear that if Asian carp move into Lake Michigan, they could cause irreversible damage to the natural biodiversity of the lake. Asian carp are bottom feeders, consuming large amounts of algae and other nutrients at the bottom of the food chain. They reproduce quickly and are voracious eaters, contributing to their rapid population explosion in the Mississippi River.

Zebra and quagga mussels are also causing significant harm to Lake Michigan. These mussels filter water and are very tiny, allowing them to pass through water filtration systems and enter our bodies when we drink water. They also clog intake pipes and cover boats, causing major issues. Quagga mussels, in particular, are superior competitors to zebra mussels and have almost completely replaced them in Lake Michigan.

The economic impact of invasive species in Lake Michigan is significant. It is estimated that invasive species cause over $5 billion in economic damage to the Great Lakes each year. For example, the invasive alewife fish experiences huge die-off events, clogging up water valves and causing problems for nuclear power plants that use lake water in their cooling systems. Some plants have had to shut down to prevent overheating when this happens, resulting in high economic costs.

Frequently asked questions