Lake Michigan's Pollution: Impact And Solutions

Lake Michigan is the largest freshwater lake in the US, with 1,600 miles of shoreline. It is a source of drinking water for Chicago and holds about 85% of North America's fresh water. However, it is facing a serious threat from pollution, mainly in the form of plastic and fertilizer. According to the Rochester Institute of Technology, 22 million pounds of plastic are dumped into the Great Lakes each year, with Lake Michigan being the most polluted lake, receiving about half of this plastic. This plastic breaks down into microplastics, which can pass through water filtration systems and be ingested by humans. Fertilizer runoff from farming is another major issue, causing harmful algal blooms that contaminate drinking water sources. While there have been efforts to clean up and protect Lake Michigan, the pollution problem persists, posing risks to the environment and public health.

Microplastics in fish and drinking water

Microplastics are a serious problem for Lake Michigan, which is part of the Great Lakes—a source of drinking water for 40 million people. According to the Rochester Institute of Technology, around 22 million pounds of plastic pollution end up in the Great Lakes annually, with Lake Michigan being the most polluted lake, receiving 11 million pounds of plastic waste.

These plastics break down into microplastics, which are tiny plastic particles under 5mm in size. They have been found in Lake Michigan fish, drinking water, bottled water, and beer. A study of three Lake Michigan tributaries discovered that 85% of the fish sampled had microplastics in their digestive tracts.

Microplastics can enter the lakes from various sources, including city water runoff, heavy winds, and rainstorms. They can also come from clothing fibres, debris from larger plastic items, and "nurdles", which are small pieces of plastic used to produce larger plastic products. Due to their small size and diverse sources, they are challenging to study and regulate.

The presence of microplastics in the food chain is a significant concern. Animals may ingest microplastics directly or absorb them through drinking water or skin contact. This can lead to developmental delays, reduced mental processing, infertility, and weakened immune systems. While the health effects on humans are not yet fully understood, microplastics have been detected in human blood, organs, and breast milk.

To address this issue, cities like Chicago have started installing filters on storm drains and sewage systems to capture macro and microplastics. Additionally, international efforts are being made to reduce plastic pollution, with the European Union prohibiting intentionally added microplastics in various products and aiming for a 30% reduction by 2030.

Fertilizer runoff

The impact of fertilizer runoff on Lake Michigan is evident in the Green Bay area, where a large dead zone occurs annually due to fertilizer pollution. This pollution causes eutrophication, which is the accelerated growth of algae due to increased nutrient concentrations. Eutrophication can lead to hypoxia, or low oxygen levels, in the water, creating dead zones that are uninhabitable for aquatic life.

Urban and suburban areas contribute significantly to fertilizer runoff. Lawns, streets, and rooftops in these regions have been found to contain high levels of nutrients, particularly phosphorus. The cumulative effect of multiple lawns in residential areas can result in a substantial increase in the nutrient content of nearby lakes. This impact is not yet fully understood and may contribute significantly to the overall nutrient load in lakes like Lake Michigan.

To address the issue of fertilizer runoff, several strategies have been proposed. One approach is the use of phosphorus-free fertilizers or fertilizers with slow-release granules. Additionally, the development of filtration systems, such as the one created by researchers at the University of Wisconsin, Milwaukee, can help prevent phosphorus-containing fertilizers from entering water bodies. This filtration system utilizes a natural material called zeolite, which is engineered with metal oxides to attract phosphorus.

The Runoff Risk Decision Support tool, developed by NOAA's National Weather Service, provides real-time forecasting guidance to farmers, informing them of the optimal time to apply fertilizers. This tool helps prevent fertilizer runoff by ensuring that fertilizers remain on the fields instead of washing off into nearby waterways. It is a voluntary tool that supplements farmers' decisions without being regulatory.

Industrial waste

Lake Erie, in particular, suffered heavily from industrial pollution due to the heavy industrial presence along its shores. Factories dumped chemical pollutants into the lake and the waterways flowing into it, such as the Cuyahoga River in Cleveland, Ohio, and the Detroit River in Michigan. As a result, dead fish began washing up along the lake's shoreline, leading to the phrase "Lake Erie is dead" in the 1960s.

Lake Michigan also faced similar issues, with oil, garbage, and industrial waste being dumped overboard from commercial ships and factories along its shores. While legislation and clean-up efforts have been implemented to address these issues, the impact of industrial waste on Lake Michigan and the other Great Lakes has been long-lasting and continues to be a concern.

Sewage

The consequences of sewage overflows are far-reaching and pose a threat to both human and wildlife health. Bacteria and viruses thrive in untreated sewage, leading to various health issues for those who come into contact with the tainted water, including skin rashes, eye and ear infections, stomach problems, and diarrhoea. Sewage overflows also result in beach closures and swim advisories, causing revenue loss for nearby communities.

To address this issue, public investment in updating wastewater systems is crucial. This not only creates jobs and saves money but also leads to cleaner water in the Great Lakes. The federal Clean Water State Revolving Fund plays a vital role in providing funding to local governments for sewer improvements and "green infrastructure" projects that divert stormwater away from the lakes.

While progress has been made, the ongoing presence of sewage overflows in Lake Michigan highlights the need for continued efforts to update and maintain infrastructure to protect the health and well-being of the surrounding communities and ecosystems.

In addition to sewage, Lake Michigan also faces pollution from other sources. Plastic pollution, for example, is a significant issue, with 11 million pounds of plastic dumped into the lake each year, according to the Rochester Institute of Technology. These plastics break down into microplastics, which can pass through water filtration systems and be ingested by people and wildlife. Fertilizer runoff from farming is another concern, as it can lead to harmful algae growth and render freshwater undrinkable.

Agricultural runoff

Fertilizer and manure from farm fields contain high levels of nutrients such as nitrogen and phosphorus, which are essential for plant growth. However, when excess amounts of these nutrients enter waterways, they can fuel harmful algal blooms and create "dead zones". This occurs when algae die and decompose, depleting the oxygen in the water and making it uninhabitable for fish and other aquatic life.

In Lake Michigan, agricultural runoff from fertilizer has resulted in large dead zones in Green Bay, according to the Alliance for the Great Lakes. This runoff not only pollutes drinking water sources but also harms the regional economy and disrupts recreational activities such as boating, swimming, and fishing on the lake.

To address this issue, the Michigan Agriculture Environmental Assurance Program (MAEAP) has been established as a voluntary program for farmers. The program includes educational seminars, risk assessments, and the development of action plans to address environmental risks. However, the program has faced controversy as some argue that it lacks strict oversight and falls short of complying with the Clean Water Act.

Additionally, new technologies are being developed to mitigate the harmful effects of agricultural runoff. For example, researchers from the University of Wisconsin-Milwaukee have created a filtration system that uses a natural material called zeolite to attract and capture phosphorus from fertilizer before it enters the water.

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