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DOE NEPA: 10 CFR 1021, the 2026 procedures and CX determinations

DOE NEPA is how the Department of Energy weighs the reasonably foreseeable environmental effects of its proposals, including funding and authorizations for applicants, before deciding[1]. 10 CFR 1021 now holds only excepted actions, DOE's existing categorical exclusions and related requirements; the rest is in the DOE NEPA Implementing Procedures, revised July 13, 2026[2][1].

By Ilya Volodarsky. 9 sources, last read on . This page explains the law; it is not legal advice.

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    How ePlan compares to drafting a CX Determination by hand

    The same document, two ways to a first draft.

    ComparedePlan.aiBy hand
    Starting pointePlan.aiA CX determination that follows a posted DOE determination or the form you upload, with your project facts filled in and gaps markedBy handA past determination, copied and edited by hand
    Precedent researchePlan.aiThe research agent searches agency project pages, the Federal Register and eCFR for your project and up to two analog projectsBy handBrowsing DOE's CX determinations by exclusion, location or office yourself
    Missing factsePlan.aiEvery fact ePlan can't confirm stays a highlighted [INSERT] placeholder until someone fills itBy handGaps surface in review, or not at all
    Cost to startePlan.aiScoping letters are free. EAs, EIRs and decision memos are on Max at $199 a monthBy handStaff or consultant hours for every draft

    ePlan.ai as of October 2026. “By hand” means a Word template, past documents and agency PDFs. Your team reviews, edits and signs every draft.

    10 CFR 1021 and the DOE NEPA procedures: what each holds

    Since July 3, 2025, 10 CFR part 1021 holds appendix A (routine actions excepted from NEPA), appendix B (DOE's categorical exclusions as of then), related requirements and an emergency provision[2][7]. DOE made that change by interim final rule, still not final on October 4, 2026[2][8]. Everything else, including exclusions added since, is in the procedures, which DOE calls guidance, not a regulation[1].

    DOE first decides whether NEPA applies; CERCLA cleanups and cross-border transmission permits, for example, do not trigger it. If it does, DOE uses an exclusion where one fits, relies on an existing document, or prepares an EA or EIS[1].

    DOE categorical exclusions: appendix B and integral elements

    Appendix B groups exclusions from facility operation (B1) to waste management (B6), and appendix C lists exclusions adopted from other agencies. Every appendix B class carries five integral elements, such as no threatened violation of safety or environmental rules and no significant impact on sensitive resources[1]. Common classes:

    • B3.6: small-scale research and development and pilot projects[1]
    • B4.13: upgrading and rebuilding existing powerlines[1]
    • B5.16: solar photovoltaic systems on buildings or previously disturbed land[7]
    • B5.23: electric vehicle charging stations[1]
    • B5.26: advanced nuclear reactors[9]

    How DOE makes a categorical exclusion determination

    DOE must find that the proposal fits one or more appendix B or C classes, was not split to fit, and has no extraordinary circumstance likely to cause a significant adverse effect. The proposal may be changed to avoid one[1].

    On September 25, 2026, ARPA-E's NEPA Compliance Officer signed CX-271092 for Tandem PV, Inc.: research on perovskite-silicon tandem solar modules at its Fremont, California plant, with field tests at Sandia in Albuquerque and in Aurora, Colorado. The form applied four classes at once: B3.6, B3.11, B5.15 and B5.16[3].

    Outline

    Categorical exclusion determination: what DOE's form records

    These follow the CX-271092 form[3] and the findings DOE's procedures require[1]. DOE's procedures are among the agency NEPA procedures that replaced CEQ's rules in 2025.

    1. Title, office and location

      Project name, DOE office, and city, county and state for each site[3].

    2. Proposed action

      What will be done, where, and with what facilities[3].

    3. Exclusions applied

      Each appendix B or C class by number and title, considered together[1].

    4. Integral elements

      A finding that all five conditions are met[1].

    5. Extraordinary circumstances and segmentation

      Findings that none applies, or how the proposal changed, and that it was not split to fit[1].

    6. Signature

      The NEPA Compliance Officer's signature and date[3].

    Sources

    Where each statement comes from

    Show all 9 sources
    1. [1]DOE National Environmental Policy Act (NEPA) Implementing Procedures. U.S. Department of Energy, July 13, 2026. Read October 2, 2026.
    2. [2]Revision of National Environmental Policy Act Implementing Procedures (DOE interim final rule), 90 FR 29676. U.S. Department of Energy, Federal Register, July 3, 2025. Read October 4, 2026.
    3. [3]CX-271092: Categorical Exclusion Determination Form, Tandem PV, Inc. (ARPA-E). U.S. Department of Energy, September 25, 2026. Read October 3, 2026.
    4. [4]DOE Categorical Exclusion (CX) Determinations. U.S. Department of Energy, Office of NEPA Policy and Compliance. Read October 2, 2026.
    5. [5]DOE Environmental Assessments. U.S. Department of Energy, Office of NEPA Policy and Compliance. Read October 2, 2026.
    6. [6]DOE Environmental Impact Statements. U.S. Department of Energy. Read October 2, 2026.
    7. [7]10 CFR part 1021 - National Environmental Policy Act Implementing Procedures (DOE), appendix B to subpart D. Electronic Code of Federal Regulations (eCFR), current. Read October 2, 2026.
    8. [8]RIN 1990-AA52, Revision of National Environmental Policy Act Implementing Procedures: Unified Agenda entry (final rule stage). Office of Information and Regulatory Affairs, RegInfo.gov. Read October 4, 2026.
    9. [9]Categorical Exclusion for Advanced Nuclear Reactors, 91 FR 4550. U.S. Department of Energy, Federal Register, February 2, 2026. Read October 2, 2026.

    Written by

    Ilya Volodarsky

    Ilya Volodarsky founded ePlan.ai. He co-founded Segment and is co-founder and CEO of Wildfires.org.

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    • Yes. B5.26, effective February 2, 2026, covers advanced reactors when DOE finds the project sufficiently limits the risk of offsite releases. It sits in DOE's procedures, not 10 CFR part 1021.

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