Environmental permitting can be challenging for large-scale linear infrastructure installation or repair projects that span multiple agency jurisdictions. Projects such as gas and electric transmission lines, telecommunications lines, water and sewer pipelines, and transportation corridors often serve regional public needs, but their geographic scale and length can increase environmental and permitting complexity. Long linear infrastructure projects often cross multiple regulatory authorities, each with distinct permitting requirements or interpretations. Without early environmental planning, permitting can become time-consuming, costly, and prone to unanticipated delays.

Unlike facility-based development, linear infrastructure projects typically result in narrow, continuous, and predictable areas of disturbance. Work often occurs within existing corridors such as roadways, utility easements, and transmission rights-of-way (ROWs), where environmental conditions are already documented, and impacts can be effectively managed. Federal regulations, including the National Environmental Policy Act (NEPA) and the Clean Water Act (CWA), recognize this pattern and provide exclusions or expedited pathways for minor utility construction, maintenance, and upgrades. As a result, the permitting process for linear projects often depends less on whether the project qualifies for an exemption or exclusion and more on whether individual activities or segments meet specific eligibility criteria.  

Is NEPA Triggered?  

A key early question for any linear project is whether NEPA applies to the construction and implementation of the proposed design. NEPA is triggered only when a federal nexus exists, such as the use of federal land, receipt of federal funding, or the need for a federal permit.

When NEPA applies, many linear activities may still qualify for established Categorical Exclusions (CEs). A CE applies when environmental impacts are expected to be minimal, allowing agencies to forgo preparation of a more detailed Environmental Assessment (EA) or Environmental Impact Statement (EIS). 

• National Telecommunications and Information Administration categorical exclusion for installation of utility and communication systems within existing ROWs (89 FR 22688)
• U.S. Forest Service categorical exclusion for approving the use of land for a utility corridor that crosses a national forest (36 CFR 220.6(e)(3))
• Federal Highway Administration categorical exclusion for utility installations along or across transportation corridors (23 CFR 771.117(c)(2)) 

Even when exemptions or exclusions are available agencies still require documentation demonstrating that sensitive resources have been adequately evaluated. Biological resources remain a common trigger for additional review. Eligibility for an exemption or exclusion typically requires that no listed species, designated critical habitat, or nesting or breeding sites will be affected. For hydrological resources, linear projects often cross wetlands, streams, or ephemeral drainages, and maintaining eligibility depends on impact thresholds, crossing methods, and cumulative effects. Cultural resources should also be evaluated early, as linear projects increase the likelihood of intersecting historic or archaeological sites that may require further review by the State Historic Preservation Office (SHPO) and potential design modifications to avoid impacts. Formal SHPO coordination is required for all projects with a federal nexus, in accordance with Section 106 of the National Historic Preservation Act.

In addition to federal resource protections, states and local agencies may impose additional regulatory requirements. Potential impacts to these resources can often be minimized through thoughtful project design, construction methodologies, and timing considerations.

Projects may lose exemption or exclusion eligibility when new ground disturbance or significant project changes are added late in the review process. Cumulative impacts can also pose challenges, for example, when multiple small wetland crossings collectively exceed allowable thresholds. Additionally, previously unknown sensitive biological or cultural resources identified after route selection can delay review and jeopardize streamlined permitting pathways.

Early, proactive coordination with agencies, land managers, tribes, and other stakeholders is one of the most effective ways to minimize these risks. Confirming eligibility criteria early helps establish clear expectations for surveys and documentation, provides regulatory predictability, and supports streamlined permitting throughout the project lifecycle.