40 CFR Part 146 Subpart H (Class VI Rule)
EPA's legal spine for geologic sequestration wells covering site criteria, Area of Review modeling, injection pressures, monitoring, and post-injection site care.
Access resourceCarbon Sequestration Resource Hub
Read the Rules Before You Inject
Geologic CO₂ storage hinges on Class VI compliance, state primacy programs, and the technical literature that proves containment. This hub brings those references together for subsurface, legal, and finance teams.
Use it as the backbone for permitting strategies, RAG stacks, and diligence workflows before anyone says “world-leading” on a slide.
Federal Backbone
Class VI rules, guidance memos, and fiscal levers that define what "secure geologic storage" actually means in the United States.
EPA Class VI Program Overview
Plain-language explainer that contrasts Class VI with EOR wells and outlines how the UIC program protects USDWs during CO₂ storage.
Access resourceEPA Final Class VI Guidance Library
Landing page collecting the issued guidance docs operators actually follow when characterizing sites, modeling plumes, and planning closure.
Access resourceSite Characterization Guidance (EPA 815-R-13-004)
Step-by-step expectations for seismic, geologic, and petrophysical data needed to prove a Class VI site can contain plume and pressure.
Access resourceArea of Review & Corrective Action Guidance
Defines AoR modeling, pressure front delineation, and corrective action planning so legacy wells do not become leakage pathways.
Access resourceWell Plugging & PISC Guidance (EPA 816-R-16-002)
How to design monitoring networks, demonstrate non-endangerment, and transition into post-injection site care.
Access resourceCRS R48033 – Class VI Wells & State Primacy
Congressional Research Service brief summarizing permitting mechanics, primacy requirements, and state implementation status as of 2024.
Access resourceCRS R44902 – Carbon Capture & Sequestration in the U.S.
Policy primer covering CCS process flow, DOE programs, EPA oversight, and how 45Q ties into deployment.
Access resourceIRS 45Q Credit for Carbon Oxide Sequestration
Defines "secure geological storage" for tax purposes and lays out credit levels, MRV (Monitoring, Reporting, and Verification) expectations, and record-keeping rules.
Access resourceCarbon Capture Coalition 45Q Primer (2025)
Financing-oriented guide clarifying when Class VI projects qualify for 45Q and how MRV (Monitoring, Reporting, and Verification) plans tie to credit integrity.
Access resourceState Primacy & Statutes
Where primacy lives, which states built bespoke CCS codes, and how local politics shape permitting throughput.
EPA UIC Primacy Scoreboard
Realtime list of states with primary enforcement authority across UIC classes, including Class VI approvals and pending applications.
Access resourceNorth Dakota Class VI Program
State-run portal for the first approved Class VI primacy program, including application forms, technical guidance, and contact points.
Access resourceWyoming DEQ Class VI CCUS
Program page detailing Wyoming's Class VI application requirements, modeling expectations, and public notice process.
Access resourceArizona Class I–VI Primacy (Federal Register 2025)
Federal Register notice granting Arizona full UIC primacy, including Class VI, and summarizing the approved rule set.
Access resourceTexas Granted Class VI Primacy (Nov 2025)
Holland & Knight analysis explaining Texas' newly approved primacy, timelines, and how it reshapes Gulf Coast hub permitting.
Access resourceLouisiana Geologic Sequestration of Carbon Dioxide Act
Title 30, Chapter 11 of Louisiana law: storage facility permits, pore space, eminent domain, and liability transfer to the state.
Access resourceLouisiana CO₂ Storage Trust Fund (Act 517)
Statutory language creating the dedicated trust fund used for long-term monitoring and remediation.
Access resourceHinshaw 2023 CCS Amendments Summary
Legal briefing on Louisiana's 2023 CCS bill, highlighting pore space provisions and local consultation requirements.
Access resourceLouisiana 2025 Directive & Temporary Limits
Governor's directive responding to community pushback, outlining additional review steps for CCS permits.
Access resourceGWPC Class VI Program Update
History of how North Dakota and other states stood up CCS statutes, plus lessons learned for new primacy applicants.
Access resourceCSG South: Carbon Capture in the South
Survey of southern-state CCS actions covering pore space, liability, revenue sharing, and incentives.
Access resourceMIT Survey of State CO₂ Storage Regulations
Comparative look at state CCS statutes, including pore space ownership, long-term care funds, and primacy objectives.
Access resourceKey Reports & Technical Docs
Foundational references from IPCC, DOE, NETL, and watchdogs that shape exploration strategy and public confidence.
IPCC Special Report on CCS (SRCCS)
Canonical 2005 assessment covering capture pathways, geologic storage options, monitoring, risks, and economics.
Access resourceGlobal CCS Institute – Global Status of CCS
Annual pipeline tracker showing operational, construction, and development-stage projects plus policy shifts worldwide.
Access resourceCATF Review of Major CCS Projects (2024)
Independent assessment of Sleipner, Snøhvit, Boundary Dam, Petra Nova, and other projects with performance takeaways.
Access resourceDOE Carbon Capture, Utilization & Storage Program
Department of Energy hub summarizing RCSPs, demonstration projects, and current storage R&D focus areas.
Access resourceNETL – Safe Geologic Storage of Captured CO₂
Synthesis of two decades of DOE storage R&D covering saline pilots, depleted reservoirs, risk assessment tools, and monitoring advances.
Access resourceCBO 2023 – Carbon Capture and Storage in the U.S.
Cost, deployment, and policy analysis detailing how CCS could scale under different assumptions and incentive regimes.
Access resourceCRS IF11861 – DOE CCS & CDR Programs
Snapshot of DOE's CCS/CDR portfolio, highlighting storage reservoir priorities and technology readiness gaps.
Access resourceCarbon Capture Coalition – Secure Geological Storage
Explains why MRV (Monitoring, Reporting, and Verification), EPA reporting, and IRS compliance must align to keep Class VI projects financeable.
Access resourceIEAGHG – Interaction of CO₂ Storage with Subsurface Resources
Classic report on how storage projects interact with other subsurface uses such as oil, gas, groundwater, and minerals.
Access resourceAcademic Reviews
Peer-reviewed syntheses that cover trapping physics, reservoir performance, monitoring, and evidence from global pilots.
Bashir et al. 2024 (Earth-Science Reviews)
Massive review of all storage options, trapping mechanisms, monitoring methods, and outstanding research questions.
Access resourceMa et al. 2022 – History & Road Ahead
Engineering journal overview connecting historical CCS deployment to future pathways and policy needs.
Access resourceMwenketishi et al. 2023 – Comprehensive Review
Preprint synthesizing trapping mechanisms, monitoring technologies, and major demonstration projects.
Access resourceMichael et al. 2010 – Saline Aquifer Experience
Case-based review covering Sleipner, Snøhvit, In Salah, Frio, Ketzin, and other formative saline storage pilots.
Access resourceCelia et al. 2015 – Modeling Deep Saline Storage
Water Resources Research article on pressure buildup, brine displacement, and multi-scale modeling approaches.
Access resourceIzadpanahi et al. 2024 – Carbon Storage in Saline Aquifers
Survey of trapping mechanisms, caprock integrity, induced seismicity, and operational challenges in saline plays.
Access resourceWiley GHG 2024 – Experimental, Modeling & Field Review
Systematic review spanning laboratory studies, numerical models, and field applications for CO₂ storage.
Access resourceRasool et al. 2025 – Evidence-Based CCS Review
Evaluates deployment data, benefits, limitations, leakage concerns, and whether CCS is keeping pace with climate goals.
Access resourceWang et al. 2025 – Mechanism, Modeling & Challenges
MDPI Energies review linking flow physics, THMC coupling, and remaining uncertainties before full-scale deployment.
Access resourceWhy This Matters
Carbon Storage Has Rules and Receipts
Class VI is the compliance backbone: if you are not designing to Subpart H plus the guidance memos, you are not storing carbon—you are gambling with USDWs.
State primacy is now the default for serious CCS hubs. Texas, Louisiana, and North Dakota want your pore space, but they also expect full AoR modeling and funding for long-term stewardship.
45Q dollars only flow when IRS definitions of secure geological storage line up with EPA monitoring and MRV (Monitoring, Reporting, and Verification) plans. Finance teams read those footnotes closely.
Two decades of DOE, NETL, IPCC, and academic work already map the error bars. Use them or repeat every experiment from scratch while the clock runs out.
Let’s Work Together
If you are looking to partner with us on your next project, please contact us at info@envitrace.com.