Resource May 2, 2023

Regional Haze Pollution in EPA Region 3

Strong state regional haze plans are critical to restoring clean air and clear skies to treasured places like Shenandoah National Park and Dolly Sods Wilderness Area. Unfortunately, states in the Mid-Atlantic are failing to adequately cut air pollution impacting these parks and wilderness areas and communities.

Average Visibility in Miles

Visibility in Shnandoah National Park

There are 156 national parks and wilderness areas designated under the Clean Air Act as “Class 1 areas,” meaning they have some of the highest levels of air quality protection in the country. However, most national park sites are still experiencing poor air quality and diminished visibility. In the Mid-Atlantic, Shenandoah National Park was found to be the third most haze polluted park in the country in an analysis done by NPCA.

The Regional Haze Rule is intended to cut pollution harming skies in these special places. Every ten years, each state must develop a plan to reduce haze-causing emissions from pollution sources within their state. The state agencies then send these plans to the U.S. Environmental Protection Agency (EPA) for approval or disapproval. In this region, West Virginia, Maryland, Delaware and D.C. have submitted regional haze plans to EPA, and D.C.’s plan has been approved.

Pennsylvania and Virginia have not yet submitted plans to EPA for this current round of planning, and Pennsylvania still does not have a plan in place from round one of haze planning over ten years ago. While Pennsylvania doesn’t have any Class I areas inside the state, pollution from Pennsylvania facilities affects Class 1 areas in nearby states.

Despite ranking 10th in the nation for the most haze pollution, West Virginia has improperly concluded that no new reductions in pollution are warranted in its proposed plan. West Virginia and Virginia are using a flawed methodology to justify ignoring nitrogen oxides (NOx) and particulate matter (PM) emissions and exempt multiple large polluting facilities from review. Read more.


In the first round of regional haze planning over ten years ago, significant emissions reductions were achieved thanks in large part to advocacy efforts for strong state plans. 1.4 million tons of haze pollution (nitrogen oxides, sulfur dioxide, and particulate matter) each year were eliminated, along with 79 million tons of climate pollution (carbon dioxide, methane, and nitrous oxide). 146 coal plants were required to either close or clean up.


The second round of haze planning is currently in progress, and many states around the country are proposing haze plans that do not cut emissions or lead to reasonable progress in reducing haze pollution in our parks. Haze plans that allow polluters to go unchecked put our parks and wilderness areas at stake, along with sensitive ecosystems, public health, and local tourism economies.


Haze pollution is also an issue of environmental justice, as many haze polluters are located in close proximity to overburdened communities. The EPA has directed states, through their haze plans, to take into consideration the intersection of people’s health and historic inequities. Many, if not most, states have not done this. NPCA will continue advocacy to EPA to ensure haze plans capitalize on the opportunity to clean up air for communities that have suffered the brunt of pollution for far too long.

Read more from NPCA