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Tackling Pollution in Maine: How To Help

Pollution—harmful substances entering the environment—threatens Maine’s wildlife, people, and communities. The state is working to clean up its polluted areas, and individual Mainers can be part of the solution.
Maine pine trees and the ocean lapping at the shore.

You can’t think about the state of Maine without thinking about its wild places. The towering pine trees, the peaceful rivers and wetlands, the ocean lapping at the shore. The creatures—birds, fish, beavers, moose—that call these places home. Even the cold, snowy landscapes of winter are part of the state’s natural beauty.

Pollution, or harmful substances that enter the environment, threatens the health of these natural landscapes. Discarded plastic bottles break down and make their way into the bodies of fish. Exhaust from cars and smokestacks chokes the air. Wastewater overflowing from sewers creates algae blooms that choke the rivers. And the state’s human residents suffer, too—both directly and indirectly.

How much pollution is there in Maine?

When it comes to pollution, the Pine Tree State is a mixed bag. A 2023 ranking of all states in U.S. News puts Maine in fifth best for levels of toxic chemical pollution. Yet in terms of air and water quality the state ranks tenth from the bottom.

Water pollution  

Each year, the U.S. Environmental Protection Agency (EPA) rates the health of each state’s rivers, lakes, coastlines, and wetlands. However, its 2022 report for Maine is largely inconclusive. While some of the state’s waters are safe for some purposes, a majority of them are marked as “insufficient information.” Maine just doesn’t have the monitoring systems to show whether its waters are up to its own health standards.

A separate EPA site provides more detailed information about each state’s drinking water quality. The information from that site is unambiguously bad news for Maine. In 2022, over 28% of the state’s public water systems were not in compliance with safety standards. Maine had 10.66 drinking water violation points per 100,000 residents—over five times the national average.

Air pollution  

The American Lung Association’s annual State of the Air report rates air quality in every U.S. state. It focuses on two air pollutants particularly harmful to human health: ozone and fine particles. In its 2023 report card, it rates 10 out of Maine’s 16 counties on at least one of these measures. The results are pretty good: A’s for most counties, and no grade below a C.

Land pollution  

One measure of land-based pollution is the EPA’s Toxic Release Inventory (TRI). It’s an accounting of all major releases of harmful chemicals into the air, water, and land of every state. The 2021 TRI lists 7 million pounds of total releases in Maine, including just under 1 million pounds on land. That’s a big number, but it’s well below average. In terms of total releases per square mile, Maine is 47th out of 56 states and territories rated.

What are the biggest causes of pollution in Maine?

Pollution in Maine comes from many different sources. As in most states, the burning of fossil fuels is a major cause of air pollution. It also contributes to water and land pollution, as air pollutants mix with rain that falls on water and soil. But there are numerous other pollutants affecting Maine’s natural environment, including sewage, industrial chemicals, and plastics.

Vehicle pollution

According to Maine’s Department of Environmental Protection (DEP), roughly half the state’s air pollution comes from vehicles. This category includes all kinds of vehicles: cars, trucks, buses, boats, trains, and farm equipment. However, cars and trucks specifically are Maine’s single biggest source of hazardous air pollution. Along with ozone and particulates, their tailpipes release large amounts of the greenhouse gases responsible for climate change.

Vehicle pollution

Point sources 

Another quarter of Maine’s air pollution comes from point sources. These are large individual facilities that release 10 or more tons of pollution in one year. The category includes power plants, paper mills, large printing operations, and other factories. They pollute the air both through their smokestacks and through accidental releases leaks, such as equipment leaks.

In Maine, power plants aren’t as big a source of pollution as they are in most states. That’s because the Pine Tree State relies less on fossil fuels for electricity and more on wind and hydropower. However, it still gets about 20% of its electricity from natural gas plants.

Nutrient pollution

According to EPA, one of the biggest known threats to aquatic life is nutrient pollution. While nutrients like nitrogen and phosphorus are essential for life, too much of them can cause harmful algae blooms. They choke off waterways, deplete oxygen levels, and release chemicals that harm other wildlife.

The top sources of nutrient pollution in Maine are wastewater and stormwater runoff from overloaded sewage systems. This water contains nutrient-laden human waste, animal waste, and fertilizer. It also carries other pollutants, including pesticides, detergents, and industrial chemicals. 


Dioxins are highly toxic chemicals produced by industrial processes that use chlorine. These chemicals build up in the food chain, from plants to fish to birds, aquatic mammals, and humans. The primary source of dioxins in Maine is paper mills that bleach paper with chlorine compounds. The state has seven such mills, which together release over 100 million gallons of wastewater per day to Maine’s rivers.


Plastic waste can be one of the most visible types of pollution. It’s easy to spot unsightly discarded bottles littering rivers, beaches, and forests. But plastic in the environment is often most harmful when it can’t be seen. Small plastic particles, called microplastics, get swallowed by fish and birds and work their way up through the food chain. Microplastic pollution can come from the breakdown of larger pieces of plastic, such as bottles and bags. But it can also enter the environment in other ways. Synthetic fabrics shed microplastics when laundered, and car tires release them into the air as dust.

Two swans in the water fighting over plastic litter

Most and least polluted areas in Maine

In most states, the most polluted areas are in or near major cities. However, the Pine Tree State doesn’t exactly follow this pattern. Maine’s biggest city is Portland, and its home county, Cumberland, has the most toxic releases on the TRI. It also gets a C, the lowest grade, for ozone pollution from the ALA. Neighboring York County also gets a C for ozone and has the second-most toxic releases in the state. But other major cities in Maine aren’t as polluted. The state’s second- and third-largest cities, Lewiston and Bangor, are both in counties that get straight A’s from the ALA.

The cleanest part of Maine is easier to pinpoint. It’s Washington County, in the eastern part of the state. It has only one toxic release reported on the TRI, and the ALA gives it an A for ozone levels.

How does pollution affect Maine residents?

Breathing polluted air or drinking polluted water contributes to all kinds of health problems. It can cause or worsen asthma, heart disease, cancer, and liver and kidney damage. Exposure during pregnancy can result in miscarriage or birth defects in children. Bacteria in the water can also spread infectious disease.

Pollution damages the state of Maine in other ways as well. It can contaminate the food supply through water or soil. It affects the health of ecosystems, sickening or killing fish, birds, plants, and other wildlife. The harm it causes to fish also threatens the livelihoods of Mainers working in the fishing industry. And it hurts the tourism industry by damaging the natural beauty that attracts visitors to Maine.

The threat of climate change compounds these problems. It worsens weather emergencies such as heat waves and storms, threatening human health, ecosystems, and industries. Already, higher temperatures are making Maine’s coastal waters warmer and more acidic, damaging fisheries. And melting sea ice is causing ocean levels to rise, endangering Maine’s coastal towns.

Pollution and environmental justice

The problems of pollution affect some Mainers more than others. People of color and people living in poverty are at the greatest risk. That’s because they’re more likely to live in the most polluted parts of the state. Cumberland and York Counties, which have the highest pollution burden, also have the largest non-White population. Cleaning up pollution in these areas is a matter of environmental justice. This is the principle that everyone, regardless of background, is entitled to a clean, safe environment.

What’s being done to clean up Maine?

Legislators and other Mainers are taking action to fight pollution in the Pine Tree State. The efforts currently under way include:

  • Habitat preservation. A 2022 law increased the amount of space the state can devote to Ecological Reserves. These are areas set aside to protect natural habitats and monitor their health. The state can now manage up to 115,000 acres under this program.
  • Better waste management. Maine’s Bottle Bill encourages Mainers to recycle by charging a refundable deposit on beverage bottles and cans. In 2023, Maine updated the program to make it more efficient and increased the per-container handling fee.
  • Water protection. Also in 2023, Maine took several steps to protect its waterways. It established a Lake Water Quality Restoration and Protection Fund to protect lakes at risk from algae blooms. It also updated the state’s mining law to ensure that any new lithium mines take steps to protect water quality.
  • Water infrastructure upgrades. In April 2023, the federal government awarded Maine $62 million for upgrades to its drinking water infrastructure. Maine’s state government set aside another $33 million in matching funds for federal drinking water and wastewater programs.
  • Climate action. In 2020, Maine created a state climate plan, “Maine Won’t Wait,” to cut greenhouse gas emissions. Within just one year, the state saw significant growth in energy efficiency, clean energy, and electric cars on the road.
  • Community solar. One way Maine is promoting clean energy is through community solar—people getting credits for the energy from a local solar farm they subscribe to. In 2019 Maine expanded community solar in the state, increasing the maximum size of projects and how many customers they could have.
Solar farm on big, open land

How you can contribute to a cleaner Maine

All Mainers can play a role in keeping the state clean. For starters, you can reduce your transportation-related emissions by driving less and walking, biking, or using public transit more. You can also reduce energy use at home by adjusting your thermostat, adding insulation, and upgrading to energy-efficient appliances. When shopping, try to avoid single-use plastic containers that contribute to pollution. And consider subscribing to a community solar program. It’s an easy way to shrink your carbon footprint and save money, too.

Your actions don’t have to stop with yourself. You can also advocate for environmental change at your workplace or in your community. Talk to your neighbors about the dangers of climate change and ways to fight it. Write to legislators at the local, state, and national level to promote pro-environment laws. Also, encourage local officials to take part in the Maine Resilient Communities Partnership program. It provides grants and technical aid to help communities reduce carbon emissions and adapt to survive climate change.

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