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Planning & Assessment

Park vistor photographing natural resources at Zion National Park, Utah.
Park visitor enjoying natural resources at Zion National Park, Utah.

Evaluating natural resource conditions, developing park management plans, and addressing requirements of the National Environmental Policy Act (NEPA) are part of internal NPS planning and assessment. In addition, NPS works with federal, state, and local agencies to ensure that proposed actions outside national parks do not harm park resources.

The Air Resources Division (ARD) has developed guidance and recommendations to assist parks, other agencies, and partners with air quality analyses needed for park natural resource condition assessments, planning, and NEPA analyses. From the tabs below, select guidance for NPS planning and NEPA (Internal Planning), NEPA actions initiated by non-NPS agencies that may affect parks (External Planning), and park Natural Resource Condition Assessments (Condition Assessment).

  • Internal Planning
  • External Planning
  • Condition Assessment
  • Resources

Guidance for Parks

Technical Guidance on Assessing Impacts to Air Quality in NEPA and Planning Documents – January 2011 (pdf, 1.3 MB)

Protecting Park Resources

The NPS Organic Act requires that parks remain "unimpaired for the enjoyment of future generations" providing a mandate for environmental protection. This gives the NPS a responsibility to ensure that internal management actions do not conflict with the purposes for which parks were established by impairing natural resources.

The NPS Management Policies (pdf, 2.5 MB) provide additional guidance for protecting parks. Section 1.4 of the Management Policies discusses Organic Act requirements.

NPS Environmental Planning

While there are many types of planning initiatives undertaken by the NPS, a large number of these fall under the requirements NEPA.  All federal agencies, including the NPS, are required by NEPA to assess and consider the environmental impacts of proposed activities.

Environmental Impact Assessments

These should include a clear methodology for assessing all impacts, including criteria for evaluating the context, intensity, and duration of the impact for a specific resource. Impact assessments identify the environmental consequences of a decision and help identify mitigation measures required to minimize or avoid adverse effects. Under our mission and mandate, NPS is also required to ensure that internal projects do not impair park resources or values (see Section 1.4 of the NPS Management Policies [pdf, 2.5 MB]).  The DO 12 Handbook (pdf, 567 KB) provides more information on NEPA specific to the NPS.


For some projects, air quality is an important resource topic, and must be addressed in the NEPA analysis. The NPS Air Resources Division assists parks with this analysis by providing:

  • the most recent and best available information on air quality conditions and trends,
  • relevant scientific studies, and
  • regulatory and policy expertise.

Generally, there are standard analysis parameters that should be applied in a NEPA analysis that considers air quality for NPS units. Therefore, ARD has developed guidance documents to assist parks and regional NEPA planners in determining:

  1. whether an air quality analysis is necessary for the project of concern;
  2. what level of analysis is appropriate for the project;
  3. what factors should be considered in the analysis;
  4. a description of appropriate types of data and methods that should be used and sources of this information.

Most importantly, this guidance helps NPS staff, contractors and external agencies evaluate whether predicted air quality effects in national parks are "negligible," "minor," "moderate," or "major."

Reaching Out

The NPS provides scientifically based guidance and related thresholds that are based on known resource effects in national parks. The guidance and thresholds are used for evaluating internal and external actions that affect air quality and resources sensitive to air pollution (also known as Air Quality Related Values – AQRVs) in national parks. This direction is applied to all planning processes including NEPA and Clean Air Act (CAA) permitting. Guidance and thresholds are useful for assessing and evaluating the severity of air pollution impacts in parks. The NPS guidance provides other agencies with a consistent and objective approach to, and methods for, evaluating air pollution impacts in national parks.

Guidance specific for NEPA assessments is available in our Technical Guidance on Assessing Impacts to Air Quality in NEPA and Planning Documents, 2011 (pdf, 1.3 MB). Among other things, this document provides guidelines on (1) determining the appropriate level of air quality analysis, (2) locating air quality information and analysis tools, and (3) interpreting the analysis results and describing the severity of air quality impacts in NEPA terms. The NEPA guidance is meant to compliment our FLAG guidance. The FLAG guidance, among other things, provides technical recommendations on appropriate AQRV modeling methods and metrics. This guidance is useful for PSD permitting analyses, but is also applicable to NEPA analyses. Recommendations in these documents are applicable to both internal and external NEPA analyses.

How does the NPS work with partners?

The NPS monitors air quality and comments on the proposals of other federal and state agencies that have the potential to affect NPS resources. The NPS participates in planning activities to ensure that significant air quality impacts are adequately addressed, and that national park resources are protected.  Working with external partners is important for protecting air quality and AQRVs in national parks because the majority of air pollution impacting parks is generated outside of park boundaries. This presents an interesting challenge because, although the NPS has legal responsibility for protecting park AQRVs, it has no direct authority to control sources of pollution located outside of parks. Responsibility for developing air pollution control plans rests with the States, Tribal governing bodies, and EPA.  Some NPS planning activities include:

NEPA - Working with external partners

The Clean Air Act (CAA), NPS Organic Act, and the Wilderness Act provide the NPS with an important role for protecting national park resources affected by air pollution from external sources. More on NPS Law and Policy »

The CAA in particular provides the NPS with a specific role and opportunity to protect parks from the effects of air pollution. However, actions implemented by other federal agencies under the purview of NEPA, such as oil and gas development, can also impact air quality and AQRVs in national parks. NPS management policies call for "cooperative conservation beyond park boundaries," recognizing that the NPS must work with federal, state and local partners to avoid or minimize external threats to park resources. The ARD works collaboratively with these agencies to ensure that air quality effects are adequately addressed in NEPA analyses and decision documents, and to achieve the maximum degree of protection possible for affected parks.

Oil & Gas Development on Federal Lands

Federal oil and gas planning and development, often addressed through the NEPA process, is a common example of the type external project the NPS reviews for air quality effects. In an effort to expand domestic oil and gas production safely and responsibly, the Department of the Interior, the Department of Agriculture, and the Environmental Protection Agency on June 24, 2011 released an interagency approach to address air quality issues associated with onshore oil and gas development on public lands. A new memorandum of understanding (MOU) establishes a common process for the agencies to follow in analyzing the potential air quality impacts of proposed oil and gas activities on federally managed public lands. The MOU's collaborative approach is designed to increase efficiency, certainty and transparency in the process—benefitting industry, federal agencies, states, and tribes. This agreement infers responsibility on the NPS to work collaboratively with an interagency group when oil and gas planning and development projects could affect National Parks. The full press release and links to information about the MOU are available through a Department of the Interior press release.

Natural Resource Condition Assessments & Resource Stewardship Strategies

“What is good air quality? Is air quality good in my park?”

National Park managers need to know the answers to these questions in order to effectively manage air quality in parks. Natural Resource Condition Assessments help parks answer these questions about air quality and other resources. A Resource Stewardship Strategy describes how to measure resource health over time to assess progress toward achieving management goals.

Learn how to evaluate park air quality conditions and set management goals that will achieve good air quality in parks. The September 2015 Guidance for Evaluating Air Quality in Natural Resource Condition Assessments (pdf, 59 KB) describes assessment methods and provides helpful links to information and data resources for air quality assessments. See Air Quality Conditions & Trends Methods to find out what levels of ozone, atmospheric deposition of nitrogen and sulfur compounds, and visibility are assigned categories of Resource is in Good Condition, Warrants Moderate Concern, or Warrants Significant Concern. Resource is in Good Condition air quality conditions are recommended for management goals.

Last Updated: January 03, 2017