Every disaster movie starts with someone not listening to a scientist. In the Norwegian movie, The Wave, a computer screen clearly shows two sinking bars on a data chart, an alarm is sounding, and the scientist who has studied and understands these alarms warns their manager—and everyone in the town—and yet is told not to worry.
Environmental Impact Assessments (EIA) under the National Environmental Policy Act (NEPA) serve as that data chart, so to speak, to inform whether an alarm should sound.
NEPA was signed into law in 1970 by President Nixon and was the first major US environmental law that requires, directs, and guides these assessments. NEPA requires that before developers start an activity—like building a highway, mine, or a power plant—there must be analysis and a public process. The law calls on the federal government to help ensure that each generation functions as a “trustee of the environment for future generations.”
Government agencies conduct EIA to determine the extent of environmental damages that may occur should a project move forward under a few different scenarios (called alternatives). Scholars have described the aim of EIA as enhanced consideration of environmental objectives to produce a more sustainable form of development. In other words: they aim to determine if environmental quality will decrease as a result of the project. Over 100 countries worldwide have adopted some form of EIA.
But the Trump administration is attacking NEPA and its implementation of EIA. For example, they are reducing the time frame for agencies to gather evidence from one year (which is standard) to 14 days—an extremely unrealistic mandate. They also repealed the regulations used to guide EIA by the White House Council on Environmental Quality, directing federal agencies to rewrite their NEPA programs prioritizing efficiency over comprehensiveness and precaution, and eliminating analyses of environmental justice and cumulative effects. Looking ahead at potential impacts through EIA results in better projects: we need to protect and improve NEPA, not weaken it.
Science is fundamental to NEPA
NEPA is viewed as a way of using science to inform and correct policymaking, and the law itself explicitly mentions science several times. For example, the law directs that during implementation, federal agencies use a “systematic, interdisciplinary approach” that integrates the natural and social sciences, and the environmental design arts such as landscape architecture and urban planning.
The law requires a Citizen’s Advisory Committee on Environmental Quality, which includes broad representation across science, industry, non-governmental, governmental, and other groups, and provides advice to the president and Council on Environmental Quality on all matters relating to NEPA. NEPA also mandates inter-agency review, including relevant state and local agencies, and ensures scientific integrity in the discussion and analysis in the EIA—and it asks that scientific data and analysis be written for lay audiences.
Most importantly, it required the creation of the White House Council on Environmental Quality (CEQ), which is tasked with enforcing the rules established under NEPA. CEQ is charged with remaining “conscious of and responsive to the scientific, economic, social, esthetic, and cultural needs and interests of the Nation.” Assessments under NEPA are EIA (the process), Environmental Impact Statements (EIS) (the resulting reports), and the state equivalents, called “mini-NEPAs.” These assessments require information and analysis from many scientific fields (i.e. biologists, chemists, economists) and the intent is that they follow the same rules as scientific research, including rigorous external peer review.
Generally speaking, EIA are a balance of available resources, available knowledge and evidence, focused on the question at hand, and almost always undertaken in politically and publicly contentious environments. One scholar of EIA suggests that—rather than hold up the requirements of full scientific rigor—“analysts should employ ‘best practicable’ scientific techniques in a holistic assessment of alternatives and consequences,” and suggests the “3 Rs:” rigorous analysis, responsive consultation, and responsible administration.
How EIS protect us
At their core, EIS describe a series of technical analyses of the nature, severity, and duration of impacts that might occur for multiple analytical scenarios. For example, for a proposed oil and gas drilling expansion project, these alternative scenarios might include inputs such as the numbers of wells that might be drilled, methods used to transport product, and the potential and location of oil spills. They sometimes include a ”no build” alternative, which describes the impacts if the proposed activity did not move forward. Prior to President Trump’s second term, the content of an EIS was regulated by CEQ. But the administration very recently rescinded that power, which included instructions to federal agencies in how to implement NEPA.
A typical EIS includes the following four sections:
- the proposed action, including its purpose and need;
- the current environmental situation (the baseline);
- a range of alternative actions;
- and the environmental impact of the proposed action and the alternatives.
This last section is where the lead government agency (sometimes called the “responsible governmental unit” or RGU) describes the bulk of the scientific and technical analyses, their results, and outlines the potential impacts to inform decision-making. So, for example if the project is a highway expansion, the Department of Transportation might be the lead agency, or RGU.
Currently, the requirements under NEPA are in flux and quite uncertain. But until very recently, governmental agencies were required to analyze the potential environmental impacts of a proposed project on the following subjects, and use the following types of technical analyses and science:
- Endangered species: The science used to study threatened or endangered species includes telemetry, audio recordings, direct surveys, satellite imaging, and camera traps. These fields of science and technology are aimed at determining how the proposed activity might impact endangered species and their habitat, and are informed by the Endangered Species Act.
- Air and water quality: Regulatory agencies assess the potential impacts from a proposed project on air and water quality using direct sampling and measurements, and inference from past scientific studies. Projects that are “permittable” must comply with the Clean Air Act and the Clean Water Act, and their related regulations. These assessments routinely employ computer models that track pollutants and chemicals released into air and water which are then transported and transformed in the environment. This sometimes includes an investigation into pollutants or emitted chemicals that plants and animals are exposed to and that may build up in their systems (i.e., bioaccumulation, biomagnification).
- Historic and cultural sites: The developer must describe alternatives that do not violate the National Historic Preservation Act by investigating the potential impacts from the proposed activity on historical and cultural sites, particularly sites of significance for Indigenous peoples. In order to do this work, analysts pull from the archeological sciences, historical documents and maps, and until very recently were incorporating Indigenous Knowledge into these assessments.
- Social and economic impacts: The EIA must also lay out social, economic, and environmental justice impacts to local communities. The economic baseline generally includes local median household incomes and unemployment rates drawn from the US Census. Then information from the proposed project is used to estimate how those conditions might change. The developer must also estimate social costs for impacts to housing stock, businesses, property values, and considerations of aesthetics and noise expected. These analyses use existing data and information gathered from the local community, and draw from methods and techniques from the social sciences such as surveys and focus groups. Developers sometimes model noise impacts using computer models or direct measurements, and at times relate it to potential health risks. This was also the section that, until very recently, included an analysis of environmental justice. These analyses split the potential impacts into different populations and compared those disparate impacts: e.g. high vs low income, urban vs rural, and comparisons of different impacts based on race and ethnicity.
A cumulative effects analysis has been part of the EIS since the US Congress enacted NEPA. These analyses require a look at the “incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency (federal or non-federal) or person undertakes such other actions.” So, for example, there must be an analysis for air quality that ensures that the proposed project plus other nearby facility air emissions and background air pollution won’t add up to exceed National Ambient Air Quality Standards.
A crucial and required part of EIA is the public participation component, where NEPA reports such as EIS are published and the RGU solicits public comments. Additionally, the RGU undertakes formal government-to-government Tribal consultation when Tribal or nearby land and resources may be impacted by the proposed project.
Science informs many aspects of this part of the process as well. EIS can be hundreds of pages long and include many research methods and techniques, and lots of technical language. Even for folks well-versed in one topic of an EIS, the next section may be a completely new-to-them field of expertise. Due to the complexity of these assessments, science communication strategies are sometimes employed to improve general understanding on the topics and potential impacts—by using better visuals, written reports, and summaries from a variety of stakeholder perspectives. In some of the more contentious projects, there can be thousands and even tens of thousands of public comments. In these instances, government analysts use a variety of qualitative assessment tools that determine topics and themes using word use frequency and correlations. Once the comments are categorized into themes, they are sent to the appropriate team who then reads and responds to determine if changes or more analysis is required to complete the EIS.
Moreover, there is also science that informs the whole purpose of public engagement around NEPA reviews, where some argue that there is a need to make environmental decision-making more responsive and transparent (i.e., democratic), and others argue that it is a way to “lean in” to the many value systems and priorities in our country.
Another attack on science
It is hugely troubling to be writing this post while the Trump administration is seemingly regressing our environmental protections back to the times before the NEPA was conceived. This requirement—to think ahead before enacting a project—grew out of the visible impacts to the environment, back when we couldn’t see across the Grand Canyon and the Cuyahoga River was still flammable.
NEPA was voted into law by a unanimous “yes” in 1970 and remains a requirement in our country to provide a “disclosure of harm” before projects are undertaken. This law, and the regulations used to implement it, do not require reduction or elimination of harm: that is the job of environmental regulations and permitting. NEPA assessments describe and outline proposed projects that are legally permittable, provide build and operation alternatives, and are used to inform environmental decision-making.
We need to continue to look ahead, supporting the folks who develop the charts with sinking data bars and audible alarms. And when the alarm sounds, we need to act!