The Environmental Protection Agency (EPA) is a federal agency in the United States that is responsible for protecting human health and the environment. Its mission is to ensure that all Americans have access to clean air, water, and land that is free from pollution. The EPA was created in 1970 by President Richard Nixon in response to growing public concern about environmental issues, such as air and water pollution, hazardous waste disposal, and oil spills.

The EPA's main responsibilities include setting and enforcing standards for air and water quality, monitoring and addressing climate change, ensuring compliance with environmental laws and regulations, and providing funding and technical assistance to state and local governments to support environmental programs. Some of its key initiatives include the Clean Air Act, which sets standards for air quality and emissions from industrial sources, vehicles, and other sources; the Safe Drinking Water Act, which regulates the safety of public drinking water systems; and the Superfund program, which cleans up hazardous waste sites across the country.

In recent years, the EPA has faced challenges including budget cuts, political opposition, and controversies over its policies and actions. However, it continues to play a crucial role in protecting the environment and public health, and remains a vital component of the US government's efforts to address global environmental issues such as climate change and sustainability.