For decades, executive permission in the form of a Presidential Permit has been required for the construction, connection, operation, and maintenance of certain facilities that cross the United States' borders with Canada and Mexico. The constitutional basis for the President's cross-border permitting authority was examined in a prior CRS report. However, questions remain about the manner in which this authority is exercised among the agencies to which it has been delegated. In particular, some Members of Congress and affected stakeholders seek greater clarity about how Presidential Permit applications are reviewed for various kinds of cross-border energy projects, including the degree to which there may be differences or similarities among the various agency approaches to evaluating environmental impacts of proposed projects and in determining whether they serve the national or public interest. With few exceptions, requests for Presidential Permits for cross-border pipelines or electric transmission lines have involved projects extending a relatively short distance into a U.S. border state before connecting to some existing facility (e.g., a refinery in Texas or a power plant in Arizona). However, in the last decade, two long cross-border pipeline projects have been approved—TransCanada's Keystone and Enbridge Energy's Alberta Clipper. In operation since 2010, both projects transport oil sands crude from Alberta, Canada, deep into the United States via pipelines that are hundreds of miles long and cross multiple states. The size and scope of these projects led to increased national attention on the Presidential Permit process for subsequent proposals. In particular, there has been significant national attention on the Department of State's process for considering TransCanada's permit application for its proposed Keystone XL pipeline. The Trump Administration issued a Presidential Permit for that project on March 23, 2017. In response to perceived delays in the review of the Keystone XL permit application, several legislative proposals in the 114 th Congress sought to change some specific or general aspects of the Presidential Permit process. Most notable was the Keystone XL Pipeline Approval Act ( S. 1 ), which was passed in Congress but vetoed by President Obama. Other legislative proposals in the 114 th Congress included the American Energy Renaissance Act of 2015 ( S. 791 and H.R. 1487 ) and the North American Energy Infrastructure Act ( S. 1228 ). Given the issues that arose in the wake of TransCanada's application for the Keystone XL pipeline, Congress may again propose legislation intended to expedite approval of future applications for Presidential Permits. This report focusses on the Presidential Permit review processes for cross-border energy infrastructure as implemented by these agencies: The Department of State for pipelines and similar facilities that transport liquids such as petroleum, petroleum products, and other hazardous liquids; The Federal Energy Regulatory Commission (FERC) for natural gas pipelines and associated facilities; and The Department of Energy (DOE) for electricity transmission lines and associated facilities. This report compares practices among these three agencies with respect to how they define a proposed project's scope (which dictates the array of associated impacts they will review), conduct environmental reviews, and make final decisions on permit applications. It also includes a discussion of recent efforts by Congress to change those permitting processes. The State Department, FERC, and DOE each make their decisions regarding Presidential Permit applications largely within the context of their own interpretation of directives in a series of executive orders. The State Department makes its permitting decisions primarily in accordance with directives in Executive Order (E.O.) 11423, as amended by E.O. 13337. FERC and DOE make permitting decisions in accordance with E.O. 10485, as amended by E.O. 12038. Broadly speaking, each executive order requires the respective agency to do the following: gather necessary project-specific information from the applicant; seek input from specific outside federal agencies; and decide whether to seek input from additional local, state, tribal, or federal agencies or from members of the public. Under the applicable executive order, each agency is required to issue a Presidential Permit if, after evaluating all relevant project information, the agency determines that the project would "serve the national interest" (pursuant to E.O. 13337) or be "consistent with the public interest" (pursuant to E.O. 10485). A permit must include any conditions that the permitting agency identifies as necessary to ensure that the project would, in fact, meet the public or national interest standard. (For the sake of brevity, the phrase public or national interest , as it is used later in this report, refers to the standard that is applied or procedures that are implemented by the authorized agency under the applicable executive order to determine whether a proposal will be "consistent with the public interest" or "serve the national interest." It does not mean to suggest that such standards or procedures are the same for each agency.) Depending on the type of project- and site-specific impacts of the project, additional federal requirements may apply to the proposal. For example, natural gas pipelines are subject to requirements established by or pursuant to the Natural Gas Act. Each agency authorized to issue Presidential Permits informs its decisionmaking regarding such permits using information gathered in accordance with its procedures implementing the National Environmental Policy Act of 1969 (NEPA). In part, NEPA requires federal agencies to ensure that the environmental impacts of an action are identified and taken into consideration before making a final agency decision about the action. Permit conditions, such as mitigation measures and additional compliance requirements, are also generally identified during the NEPA review. For example, during the NEPA review, an agency may identify construction procedures or mitigation measures that the applicant must implement to ensure compliance with other applicable federal law, such as the Endangered Species Act or Clean Water Act. Since each agency is required to identify conditions under which a proposal must be implemented, it is rare that an agency denies a permit application. Instead, the permitting process is generally used to determine how a project must be implemented to comply with federal law (and meet the national or public interest standard) rather than whether it can be implemented. In 2015, the State Department under the Obama Administration did deny TransCanada's application for a Presidential Permit, finding that the pipeline would not meet the national interest. However, such a decision was a rare exception, not the rule. Each agency's permitting process involves the identification and analysis of project-specific impacts of a proposal. That information is gathered in accordance with executive order directives, the agency's NEPA implementation process, and any other applicable federal requirements. Once a Presidential Permit is issued, the applicant (then permittee) must site, construct, operate, and maintain the border-crossing facilities in accordance with conditions specified in the permit. As a result, subsequent modifications to the facility related to its siting, construction, operation, or maintenance may require additional authorization from the permitting agency. As stated above, each permitting agency identifies the impacts of a proposed project and conditions necessary to ensure it will meet the required public or national interest standards, largely within the context of identifying environmental impacts pursuant to NEPA. In 1978, the Council on Environmental Quality (CEQ) promulgated regulations implementing NEPA that are broadly applicable to all federal agencies. In those regulations, each federal agency was required to adopt the CEQ regulations, supplement them as necessary to include procedures relevant to that agency's authority, and ensure that those procedures implementing NEPA are integrated into the agency's broader decisionmaking procedures. FERC, DOE, and the State Department subsequently did so. The resulting agency-specific NEPA review process is used to identify any potentially relevant issues or impacts that must be considered during the decisionmaking process. Procedures for determining the scope of the environmental review and the type of impacts analyzed during that review are delineated in both the CEQ and the individual agency NEPA regulations. NEPA requires federal agencies to provide a detailed environmental impact statement (EIS) for "major federal actions significantly affecting the quality of the human environment." If the agency is uncertain whether a proposal would have significant impacts, it may prepare an environmental assessment (EA) to determine if an EIS is necessary, or a finding of no significant impact (FONSI) may be issued. Federal agencies may also identify categories of actions they are authorized to undertake that have been found to have no significant effect on the environment. Such actions are categorically excluded from the need to prepare an EIS or EA and are, hence, broadly referred to as "categorical exclusions" (CEs or CATEXs). Given the various potential types of review required under NEPA (i.e., preparation of an EIS or EA or approval as a CE), the scope of project-specific information that will be used to inform an agency's public or national interest determination depends on whether the proposal will "significantly" affect the environment. That determination must be based upon each agency's evaluation of these effects of the proposal: Direct effects that are caused by the project and occur at the same time and place (e.g., impacts directly associated with the construction and operation of the cross-border facilities). Indirect effects that are caused by the action and are later in time or farther removed in distance but still reasonably foreseeable. Cumulative impacts on the environment that result from the incremental impacts of the action when added to other past, present, or reasonably foreseeable future actions regardless of what agency (federal or nonfederal) or person undertakes that other action. The definitions of these categories of impacts mean that, although a Presidential Permit may be for cross-border facilities, the scope of environmental review of domestic impacts is not limited to the evaluation of impacts that occur only at the border. With few exceptions, each agency has determined that it must evaluate the impacts of an entire project within the United States—from the border to its eventual connection in U.S. territory.