NEPA Decarbonization Technology Analysis: Deliverable 4

Multi-State and Multi-Department Projects

Published

March 18, 2026

Executive Summary

Key Findings
  • Multi-state projects represent a subset of decarbonization technology projects that span state boundaries, often involving transmission lines or large-scale renewable energy connections
  • Strict multi-department projects (based on multiple lead agencies in metadata) are relatively rare
  • Expanded multi-agency projects (strict metadata OR high-confidence coagency text signal) produce a materially larger N
  • Geographic patterns reveal regional clusters of interstate cooperation

This report aims to create the following set of deliverables:

Data on geography/project location; whether projects are multi-state or multi-agency

It analyzes decarbonization technology projects that cross administrative boundaries—either spanning multiple states or involving multiple federal agencies. These projects often represent larger, more complex undertakings that require coordination across jurisdictions. Table 1 reports total multi-state and multi-department project counts used in this report.

Table 1: Summary of cross-boundary projects
Category Count
Multi-state projects 841
Multi-department projects 301
Note that some tables and figures below are filtered for clarity: the state connections table shows only state pairs with 5+ shared projects, the interstate map shows only state pairs with 10+ shared projects, and the top connections table shows the 10 highest-volume corridors.

The multi-department count reflects projects identified with the current expanded multi-department definition.

Multi-State Projects

Multi-state projects are those where the project footprint extends across state boundaries. These typically include:

  • Interstate transmission lines
  • Pipeline connections
  • Large renewable energy projects near state borders

Process Type Breakdown

Figure 1 shows the distribution of NEPA process types among all multi-state decarbonization technology projects.1

Figure 1: Distribution of NEPA process types for multi-state decarbonization technology projects

State Connections Table

Table 2 shows state connection pairs with 5 or more shared projects, broken down by NEPA review process type. This threshold filters out infrequent connections to focus on the most active interstate corridors.

Interstate Connections Map

Figure 2 visualizes the connections between states that share decarbonization technology projects. Line thickness reflects the number of shared projects, with labels highlighting the most active connections.

Figure 2: Interstate decarbonization technology project connections. Line thickness reflects number of shared projects; labels show counts for top connections.

Top Connections Detail

Table 3 provides detail on the top 10 state connections by project volume, including the types of projects involved. Project types are deduplicated and sorted by frequency.

Table 3: Top 10 interstate connections with project types (sorted by frequency)
State Connections Distinct Project Types1 Categorical Exclusion Environmental Assessment Environmental Impact Statement Total
Oregon - Washington Electricity Transmission, Utilities, Waste Management, Land Development - Other, Surface Transportation - Other, Water Resources - Other, Broadband, Vegetation and Fuels Management, Public and Recreational Land Use, Ecosystem Management and Restoration, Land Use or Forest Management Plan, Land Development - Urban, Renewable Energy Production - Hydropower, Surface Transportation - Bridges, Renewable Energy Production - Energy Storage, Routine Maintenance, Threatened and Endangered Species Management, Water Resources - Irrigation and Water Supply, Agriculture, and Guidance, Data Storage and Data Management, Emergency and Disaster Response, Laws, Policies, Regulations, Renewable Energy Production - Biomass, Renewable Energy Production - Geothermal, Renewable Energy Production - Solar, Research and Development 78 1 8 87
Kansas - Missouri Utilities, Research and Development, Surface Transportation - Other, Waste Management, Land Development - Urban, Manufacturing, Renewable Energy Production - Energy Storage, Electricity Transmission, and Guidance, Conventional Energy Production - Other, Laws, Nuclear Technology, Policies, Regulations, Surface Transportation - Public Transportation, Water Resources - Other, Land Development - Housing, Land Development - Other, Military and Defense, Renewable Energy Production - Biomass, Renewable Energy Production - Geothermal, Renewable Energy Production - Other, Renewable Energy Production - Solar, Agriculture, Data Storage and Data Management, High Performance Computing and Advanced Computer Hardware and Software, Land Use or Forest Management Plan, Onshore, Renewable Energy Production - Wind, Water Resources - Irrigation and Water Supply 47 0 3 50
Colorado - New Mexico Utilities, Electricity Transmission, Land Development - Other, Broadband, Land Use or Forest Management Plan, Surface Transportation - Other, Waste Management, and Guidance, Laws, Policies, Regulations, Vegetation and Fuels Management, Conventional Energy Production - Other, Research and Development, Water Resources - Other, Ecosystem Management and Restoration, Land Development - Housing, Renewable Energy Production - Solar, Agriculture, Rangeland Management, Renewable Energy Production - Energy Storage, Threatened and Endangered Species Management, Water Resources - Irrigation and Water Supply 40 0 3 43
Virginia - West Virginia Research and Development, Waste Management, Utilities, Conventional Energy Production - Other, Land Development - Other, and Guidance, Laws, Policies, Regulations, Renewable Energy Production - Solar, Data Storage and Data Management, Renewable Energy Production - Biomass, Carbon Capture and Sequestration, Electricity Transmission, High Performance Computing and Advanced Computer Hardware and Software, Onshore, Renewable Energy Production - Geothermal, Renewable Energy Production - Other, Renewable Energy Production - Wind, Conventional Energy Production - Nuclear, Emergency and Disaster Response, Habitat Conservation Plan, Land Development - Housing, Land Development - Urban, Manufacturing, Nuclear Technology, Public and Recreational Land Use, Renewable Energy Production - Energy Storage, Surface Transportation - Other, Water Resources - Other 27 0 1 28
Nebraska - Nevada Utilities, Electricity Transmission, Land Development - Other, Broadband, Ecosystem Management and Restoration, Water Resources - Irrigation and Water Supply, Conventional Energy Production - Other, Research and Development, Surface Transportation - Other, Threatened and Endangered Species Management, Waste Management, and Guidance, Land Development - Housing, Laws, Mining - Non-Metallic Minerals, Onshore, Policies, Regulations, Renewable Energy Production - Solar, Renewable Energy Production - Wind, Routine Maintenance, Vegetation and Fuels Management, Water Resources - Other 21 0 0 21
California - Nevada Electricity Transmission, Utilities, Vegetation and Fuels Management, Ecosystem Management and Restoration, Land Development - Other, Land Use or Forest Management Plan, Public and Recreational Land Use, Renewable Energy Production - Biomass, Renewable Energy Production - Geothermal, Renewable Energy Production - Hydropower, Renewable Energy Production - Solar, Waste Management, Water Resources - Other, Conventional Energy Production - Nuclear, Conventional Energy Production - Other, Emergency and Disaster Response, Nuclear Technology, Onshore, Rangeland Management, Renewable Energy Production - Other, Renewable Energy Production - Wind, Research and Development, Routine Maintenance, Surface Transportation - Other, Threatened and Endangered Species Management 6 3 11 20
Arizona - California Electricity Transmission, Utilities, Vegetation and Fuels Management, Surface Transportation - Other, Waste Management, Land Development - Other, Land Use or Forest Management Plan, Routine Maintenance, Water Resources - Irrigation and Water Supply, Conventional Energy Production - Other, Threatened and Endangered Species Management 9 4 5 18
Arizona - California - Nevada Electricity Transmission, Utilities, Waste Management, and Guidance, Laws, Policies, Regulations, Vegetation and Fuels Management, Ecosystem Management and Restoration, Renewable Energy Production - Hydropower, Routine Maintenance, Threatened and Endangered Species Management, Water Resources - Irrigation and Water Supply, Water Resources - Other, Agriculture, Broadband, Data Storage and Data Management, Land Development - Other 13 2 2 17
Colorado - Washington Electricity Transmission, Utilities, Vegetation and Fuels Management, Broadband, Ecosystem Management and Restoration, Emergency and Disaster Response, Land Use or Forest Management Plan, Rangeland Management, Routine Maintenance 17 0 0 17
Nebraska - Wyoming Electricity Transmission, Utilities, Vegetation and Fuels Management, Waste Management, Broadband, Onshore, Renewable Energy Production - Wind, Surface Transportation - Other, Water Resources - Other 11 2 0 13
1 Project types are ordered by frequency of appearance within each state connection.

Word Clouds by NEPA Process Type

The next three figures break multi-state project types out by NEPA process type.

Figure 3: Multi-state project types word cloud for Categorical Exclusions (CE).

Figure 4: Multi-state project types word cloud for Environmental Assessments (EA).

Figure 5: Multi-state project types word cloud for Environmental Impact Statements (EIS).

Sample of Complex Multi-State Projects

Table 4 shows a small sample of projects that span many states and/or very wide state footprints.

Table 4: Sample of geographically complex multi-state projects
Project Title State Footprint Number of States Project Types
MacroAlgae Research Inspiring Novel Energy Resources (MARINER) Program (FOA No. DE-FOA-0001726) Alabama, Alaska, California, Colorado, Connecticut, Delaware, District Of Columbia, Florida, Georgia, Hawaii, Illinois, Louisiana, Maine, Maryland, Massachusetts, Mississippi, New Hampshire, New Mexico, New York, North Carolina, Oregon, Pennsylvania, Texas, Washington, Wisconsin 25 Renewable Energy Production - Biomass, Research and Development, Agriculture, Waste Management, Water Resources - Other
Harnessing Emissions into Structures Taking Inputs from the Atmosphere (HESTIA) Program Alaska, Arizona, California, Colorado, Florida, Georgia, Illinois, Indiana, Maine, Massachusetts, Michigan, New York, North Carolina, Oregon, Pennsylvania, South Carolina, Tennessee, Texas, Washington, Wisconsin 20 Research and Development, Carbon Capture and Sequestration, Manufacturing, Waste Management, Land Development - Housing, Land Development - Urban
Submarine Hydrokinetic and Riverine Kilo-Megawatt Systems SHARKS Alaska, California, Colorado, Georgia, Illinois, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Tennessee, Texas, Virginia, Washington, Wisconsin 20 Renewable Energy Production - Hydrokinetic, Research and Development, Waste Management, Water Resources - Other
Nationwide Public Safety Broadband Network for the Non-Contiguous United States Alaska, Hawaii 2 Broadband, Utilities, Emergency and Disaster Response
Campbell Creek Science Center, Exterior Power Restoration (Light Pole) Project Alaska, Nebraska 2 Electricity Transmission, Utilities
Aerodynamic Turbines, Lighter and Afloat, with Nautical Technologies and Integrated Servo-control (ATLANTIS) Program Alabama, California, Colorado, Illinois, Maine, Maryland, Massachusetts, Michigan, New Jersey, New Mexico, New York, Rhode Island, Texas, Utah, Virginia, Washington 16 Renewable Energy Production - Wind, Offshore, Research and Development, Waste Management, Artificial Intelligence and Machine Learning, High Performance Computing and Advanced Computer Hardware and Software
Harnessing Emissions into Structures Taking Inputs from the Atmosphere (HESTIA) Program (FOA Numbers DE-FOA-0002625 and DE-FOA-0002626) Colorado, Georgia, Illinois, Indiana, Maine, Massachusetts, Michigan, New York, North Carolina, Pennsylvania, South Carolina, Tennessee, Texas, Washington, Wisconsin 15 Research and Development, Carbon Capture and Sequestration, Manufacturing, Waste Management, Land Development - Housing
Cobscook Bay Tidal Energy Project Maine, Washington 2 Renewable Energy Production - Hydrokinetic, Renewable Energy Production - Hydropower
Bangor Hydro-Electric Company Northeast Reliability Interconnect Maine, Washington 2 Electricity Transmission
Underwater Active Acoustic Monitoring Support for Marine Hydrokinetic Energy Projects Maine, Washington 2 Renewable Energy Production - Hydrokinetic, Research and Development, Manufacturing, Ecosystem Management and Restoration, Water Resources - Other

Multi-Department Projects

This section reports two definitions:

  • Strict metadata: project_multi_department (multiple lead agencies in metadata).
  • Expanded multi-department: project_multi_agency (strict metadata OR high-confidence coagency text signal from document pages).

Process Type Breakdown

Figure 6 shows the distribution of NEPA process types for the expanded multi-department definition.

Multi-department projects are overwhelmingly EIS-level reviews (89%), with CEs and EAs together accounting for just 11% of the portfolio. This is a much sharper EIS skew than in the multi-state population, and it makes conceptual sense: EIS reviews are the longest and most resource-intensive NEPA pathway, and the need to formally coordinate across multiple federal agencies is most common in exactly these high-complexity situations. Projects requiring EIS-level review are the ones most likely to trigger interagency involvement through cooperating agency relationships or overlapping jurisdictions.

Figure 6: Distribution of NEPA process types for expanded multi-department decarbonization technology projects.

Department Connections Table

Table 5 lists agency combinations that share projects, along with the types of projects involved. Project types are deduplicated and sorted by frequency.

The Department of Energy appears in nearly every multi-department pairing, reflecting its central role in both permitting energy infrastructure and managing research facilities. The most project-rich combinations are DOE with DOD (3 shared projects spanning transmission, R&D, and military-adjacent energy uses) and DOE paired with DOI, USDA, Commerce, and GSA (2 projects each). Project types signal two distinct collaboration logics: an energy-infrastructure track (electricity transmission, utilities, renewable energy production) and a research-and-management track (R&D, ecosystem management, waste management). The DOI–Homeland Security pairing stands out as non-DOE coordination, anchored by solar and emergency-preparedness projects.

Department Collaboration Hubs

Table 6 ranks departments by their collaborative footprint. The bridge score combines breadth (number of unique partner departments) with volume (total shared project ties, log-scaled) to identify departments that are both broadly connected and frequently involved—not just departments with one large partnership.

Table 6: Department collaboration hubs in strict metadata multi-department projects
Department Unique partner departments Collaborative project ties Most frequent partner Projects with top partner Bridge score
Department of Energy 9 34 Department of the Interior 4 32.00
Department of the Interior 4 16 Department of Energy 4 11.33
Department of Agriculture 2 6 Department of Energy 2 3.89
Department of Homeland Security 2 6 Department of the Interior 2 3.89
Department of State 2 4 Department of Energy 1 3.22
International Assistance Programs 2 4 Department of Energy 1 3.22
Department of Defense 1 6 Department of Energy 3 1.95
Department of Commerce 1 4 Department of Energy 2 1.61
General Services Administration 1 4 Department of Energy 2 1.61
Department of Housing and Urban Development 1 2 Department of Energy 1 1.10
Department of Transportation 1 2 Department of the Interior 1 1.10

Figure 7: Department collaboration hubs. Bars show bridge score; labels show each department’s most frequent partner.

DOE stands out as the clear hub of the multi-department network, with a bridge score (26) more than three times that of DOI (9). Its dominance reflects both the sheer number of partner agencies (9 unique departments) and the high volume of shared project ties. DOI is a meaningful secondary hub, with its strongest partnership running back to DOE. All other departments are more peripheral—connecting to one or two partners and typically anchored to DOE as their primary collaborator.

Figure 8: Cross-department project flows. Flow width reflects number of shared projects.

The Sankey confirms the hub-and-spoke character of multi-department collaboration: DOE is the dominant node on both sides of the diagram, with the largest flows connecting it to DOD, DOI, and USDA on the left and back to DOI, Homeland Security, and Commerce on the right. The right side of the diagram has more nodes than the left, reflecting the variety of secondary partners DOE draws in depending on project type. Most other department-to-department pathways carry only one or two shared projects and appear as thin ribbons at the base of the diagram.

Word Clouds by NEPA Process Type

The next three figures break multi-department project types out by NEPA process type. Because multi-department CEs and EAs are few (20 and 14 projects respectively), their word clouds reflect a narrow set of project types. EIS, which accounts for the bulk of the portfolio, shows the broadest vocabulary.

Figure 9: Multi-department project types word cloud for Categorical Exclusions (CE).

Figure 10: Multi-department project types word cloud for Environmental Assessments (EA).

Figure 11: Multi-department project types word cloud for Environmental Impact Statements (EIS).

Report generated 2026-03-18 | NEPA Decarbonization Technology Analysis

Footnotes

  1. State-pair tables are filtered to connections with 5+ shared projects and the map to 10+ shared projects, so Ns below Figure 1 are intentionally lower.↩︎