The Environmental Protection Agency, under the Clean Air Act, requires states to work with the EPA to address the interstate transport of air pollution. Under the “Good Neighbor Plan,” the EPA requires each state to implement – as part of its State Implementation Plan – regulations that will reduce emissions, which prevent downward states from attaining or maintaining National Ambient Air Quality Standards. The Act further requires the EPA to backstop any state actions that it does not approve or to develop Federal Implementation Plans when states do not do so.
The purpose of the Good Neighbor Plan is to prevent cross-state pollution. This pollution is created in one state and then blown downwind to another state. Some emissions – such as sulfur dioxide and nitrogen oxides – can undergo chemical reactions in the atmosphere that create fine particle pollution or soot. These particles can travel hundreds of miles and impact public health. The particles also make it difficult for downwind states to meet emission standards.
Sources of the particle pollution include power plants and automobiles. The size of the particulates determines their impact on public health. Smaller particles – less than 10 microns in diameter – can affect both the lungs and heart. These impacts can include premature death in those with pre-existing lung and heart disease; irregular heartbeat; aggravated asthma; decreased lung function; and difficulty breathing. Older adults and children are most likely affected. The particulate pollution also impacts the environment, making lakes and streams acidic; changing the nutrient balance in coastal waters; depleting nutrients in soils; damaging crops; and contributing to acid rain.
The final Good Neighbor Plan was issued in March 2023. In September 2023, a plan to control nitrogen oxides was implemented in 23 states that the EPA determined needed federal plans to backstop inadequate or non-existent state plans. The EPA reported in November 2023 that power plants had significantly reduced their nitrogen oxide emissions even in the face of judicial rulings, which limited the participation to power plants in only 10 states. Since 2015, the emissions have decreased 50% under cross-state programs. Emissions in the 10-state area subject to the 2023 Good Neighbor Plan were 25% below the effective regional budget. The EPA also estimates that implementation of the federal plans will save up to 1,300 lives in 2026. More than 115 million people live in areas that fail to meet federal guidelines for nitrogen oxide emissions.
On December 20, 2023, the Supreme Court agreed to hear a case involving the Good Neighbor Plan and will hear oral arguments in February 2023. The case before the justices involves challenges by pipeline operators including regional electricity generators and energy trade associations. These challenges come out of Ohio, West Virginia, and Indiana.
The parties challenging the rule argue that the EPA violated a federal law aimed at ensuring agency actions are reasonable. The parties have asked the Supreme Court to block enforcement against natural gas pipeline engines, as well as iron and steel mill reheating furnaces and boilers. The parties argue that the plan will destabilize the states’ power grids and create unreasonable costs to enforce the plan. The justice department argued that blocking the rule would create harm to downwind states that suffer from upwind states’ emissions. It also argued that blocking the plan creates serious public health risks.
If the Supreme Court blocks enforcement of the Good Neighbor Plan, it could severely impact the administration’s goals for more clean air and less use of coal.
