Primary Enforcement Authority for the Underground Injection Control Program
On this page:
- What is UIC primary enforcement responsibility (primacy)?
- What states, territories, and tribes have primacy?
- Who implements the program in states, territories, and tribes that do not have primacy?
- What is the process for states, territories, and tribes to apply for primacy or implement a substantial program revision?
- What are the core elements of a primacy application or program revision?
- What states, territories, and tribes are currently in the primacy application or substantial program revision process?
- What states, territories, and tribes have recently completed a primacy application or substantial program revision process?
- Comprehensive UIC program evaluations
Section 1421 of the Safe Drinking Water Act (SDWA) requires EPA to develop UIC program requirements that protect underground sources of drinking water from endangerment. EPA has developed UIC program requirements that are designed to be adopted by states, territories, and tribes.
Primary enforcement responsibility, often called primacy, refers to state, territory, or tribal responsibilities associated with implementing EPA approved UIC programs. A state, territory, or tribe with UIC primacy, or primary enforcement authority oversees the UIC program in that state, territory, or tribe.
Primacy programs are established under Sections 1422 and 1425 of the SDWA. Section 1422 requires primacy applicants to meet EPA’s minimum requirements for UIC programs. Programs authorized under this section, referred to as 1422 programs, may have primacy for Class I, II, III, IV, V, and VI wells.
Under Section 1422, applicants may submit primacy applications for:
- All well classes
- Classes I – V
- Class VI (only)
Section 1425 requires primacy applicants to demonstrate their standards are effective in preventing endangerment of USDWs. Section 1425 programs are not required to meet EPA’s minimum requirements, provided applicants can show their standards protect USDWs. Section 1425 applies to Class II wells only.
EPA may grant primacy for all or part of the UIC program. This means that in some jurisdictions primacy for certain well classes may be shared with EPA or divided between two different state, territory or tribal authorities.
States seeking UIC program primacy must demonstrate to EPA that the state has: jurisdiction over underground injection; regulations that meet the federal requirements for 1422 programs (or are effective under Section 1425); and the necessary administrative, civil and criminal enforcement penalty remedies.
EPA has approved UIC primacy programs for multiple well classes in thirty-one states and three territories. Multiple well classes generally include I, II, III, IV, and V. EPA retains direct implementation authority for class II wells in Florida and Idaho. Seven states and two tribes have approved primacy programs for Class II wells only. North Dakota and Wyoming are the only states with primacy for all well classes (I, II, III, IV, V, and VI). EPA implements the Class VI program in all other states, territories, and tribes. Additionally, EPA directly implements the full UIC program in eight states, two territories, the District of Columbia, and all Indian tribes (except for class II wells on Navajo and Fort Peck ).
Use your cursor and hover over the states in the map below, or refer directly to the table, for state-specific primacy information.
UIC Primacy Map
|Fort Peck Tribes
|All Other Indian Tribes.
|EPA manages all well classes.
|State has primacy for Class II wells only.
|State has primacy for multiple well classes.
|State has primacy for all well classes (Classes I, II, III, IV, V and VI).
If a state, territory, or tribe does not obtain primacy for all or some UIC well classes, EPA implements the program directly through one of its regional offices. Currently, EPA implements the UIC program for all well classes in nine states and two territories. Apart from the Navajo Nation and Fort Peck Class II programs, EPA directly implements the UIC program in Indian country.
What is the process for states, territories and tribes to apply for primacy or implement a program revision?
The UIC primacy application process is presented at 40 CFR part 145 and includes requirements for states, territories and tribes applying for UIC program primacy. Additionally, EPA guidance documents describe the general procedures for the Agency's review and approval of primacy and program revision applications. These documents include:
- Guidance for Review and Approval of State Underground Injection Control Programs and Revisions to Approved State Programs - Ground Water Program Guidance #34 (Guidance 34) provides guidance to EPA regional offices on the process for the approval of state primacy application and the process for approving program revisions for programs approved under both 1422 and 1425.
- Guidance for State Submissions Under Section 1425 of the Safe Drinking Water Act (SDWA) - Ground Water Program Guidance #19 (Guidance 19) provides guidance on: how states may apply for primacy approval under Section 1425 of the SDWA and the criteria EPA will use in approving or disapproving an application (applies only to Section 1425 applications).
Consistent with these guidance documents and governing EPA regulations, EPA’s UIC Program developed operating procedures to streamline the review and approval process and to facilitate transparency and consistency in primacy and program revision evaluations and approvals. These procedures divide EPA’s responsibilities and interactions with states, territories and tribes into four general phases.
- Phase I: pre-application activities
- Phase II: completeness review and determination
- Phase III: application evaluation
- Phase IV: rulemaking and codification
Phase I: pre application activities
This phase begins when EPA engages with a state interested in applying for UIC program primacy or implementing a program revision. During this phase, EPA may support a state in identifying available resources and the critical elements (i.e., the governor’s letter, attorney general’s letter, program description, memorandum of agreement, and public participation documentation) of a primacy application or program revision. EPA may also meet with the state to outline the process, address preliminary questions a state, territory or tribe might have, and determine the scope of a state’s actions (e.g., all well classes, Class II only, or Class I – V, or Class VI only).
Additionally, EPA may work with the state to review the state’s draft UIC statutes and regulations and encourage a state to complete a comparison crosswalk. The crosswalk provides a method to efficiently compare the federal regulations with the state's draft statutes and regulations.
Phase II: completeness review and determination
During the Completeness Review and Determination Phase, EPA receives and reviews complete drafts of applicable critical elements of a state submission including the governor’s letter, attorney general’s letter, program description, memorandum of agreement, and public participation documentation. The EPA and a state may engage in a continued dialogue to ensure that questions are clarified prior to the end of this phase. It is also possible that a state, territory or tribe may identify regulatory or statutory changes that must be implemented prior to completion of this phase.
Phase III: application evaluation
The Application Evaluation Phase encompasses a comprehensive evaluation of the regulations and other elements of the primacy application or program revision package. During this phase, EPA will evaluate, in detail, every aspect of each element and coordinate with an applicant to gain clarity and confirm stringency or effectiveness.
During this phase, EPA publishes a proposed rule signed by the EPA Administrator which indicates EPA’s intent to approve or disapprove of a primacy application or program revision. The public is given at least 30 days to comment on the state’s UIC primacy application during which time the public may request a hearing. When a public hearing is requested, EPA arranges the date, time and location of the hearing, and notifies the public.
At the close of the public comment period, EPA reviews public comments received during the public hearing as well as written comments submitted to the EPA Docket. Depending on the comments, EPA may re-review the state’s primacy application and request changes.
Phase IV: rulemaking and codification
During Phase IV, EPA drafts the final rule approving, or disapproving, the state’s primacy application or program revision. The final rule package includes: a summary of the public comments and EPA’s responses; documentation of any changes from the state’s original application and EPA’s rationale for finalizing the rule with such changes; and the regulatory text that will be codified in 40 CFR part 147 after the program is approved.
The final rule is signed by the EPA Administrator and published in the Federal Register with the date of publication as the rule’s effective date.
UIC Program regulations at 40 CFR part 145 identify six core elements of a UIC primacy application or substantial program revision. Each of the six requirements are identified below. For a new primacy application all documents are required. For program revisions, depending on the nature of a state’s UIC program changes, a state may need to revise one or more of the six core elements and submit a revised primacy application to EPA.
This core element is a signed letter from the governor of the state requesting approval for UIC program primacy. The governor's letter must specify that approval is sought under sections 1422 or 1425 of the SDWA.
This core element is a document describing in narrative form the scope, structure, coverage and processes of the state program.
Attorney general's statement
The Attorney General's statement is a certification by a qualified representative of the state, asserting that the state’s statutes, regulations and judicial decisions demonstrate adequate authority to administer the UIC program.
Memorandum of agreement between the state and the EPA regional administrator
The memorandum of agreement (MOA) is the central agreement setting out the provisions and arrangements between the state and EPA. The MOA describes the administration, implementation and enforcement of the state’s UIC program.
Copy of the state's UIC statutes and regulations
States seeking primacy under Section 1422 may incorporate the federal regulations by reference, adopt the federal language verbatim, or draft provisions that are as stringent as the federal requirements.
States seeking primacy under Section 1425 must demonstrate that their Class II regulations are effective in preventing underground injection that endangers USDWs.
Documents demonstrating the state's public participation process
The state must provide documentation of the public participation process the state used to notify the public of its intent to apply for primacy.
What states, territories, and tribes are currently in the primacy application or program revision process?
Status of state, territory, and tribal primacy and program revision applications
What states, territories, and tribes have recently completed the primacy application or program revision process?
EPA has recently approved an application from New Mexico under the Safe Drinking Water Act to revise the state’s existing Underground Injection Control (UIC) program. New Mexico has revised its UIC Class I program regulations to establish new permit conditions, oversight, and enforcement requirements to manage Class I hazardous waste injection activities by petroleum refineries in such a manner that is protective of underground sources of drinking water. This program revision only affects UIC wells under New Mexico’s authority, EPA remains the permitting authority for the UIC program in Indian country. With this action, EPA is also codifying previously approved, non-substantial changes to the New Mexico UIC program.
EPA is issuing a final rule approving Michigan’s Class II UIC program for primacy. EPA has determined that the State’s program is consistent with the provisions of the Safe Drinking Water Act to prevent underground injection activities that endanger underground sources of drinking water (USDWs). EPA’s approval allows Michigan to implement and enforce the State’s regulations for Class II UIC wells, which cover oil and gas related injection well activities. EPA will remain the permitting authority for all other UIC well classes in Michigan and the sole permitting authority for all UIC well classes in Indian country within the State.
Summary of Action
On December 28, 2023, the U.S. Environmental Protection Agency (EPA) signed a final rule granting the State of Louisiana’s request for primary responsibility for the permitting, compliance, and enforcement of Class VI (carbon sequestration) wells under the Underground Injection Control Program (UIC). Under the Safe Drinking Water Act, EPA has developed stringent federal requirements for injecting CO2 that protect public health by ensuring injection wells do not contaminate underground sources of drinking water. These UIC regulations mandate using a variety of measures to assure that injection activities will not endanger these vital sources of drinking water.
On September 17, 2021, Louisiana submitted to EPA a program revision application to add Class VI injection wells to the state’s existing federally approved UIC program. After considering input from four public hearings and an extensive review of over 45,000 comments received from the proposal and a Notice of Availability, EPA determined that the State of Louisiana’s Class VI UIC program meets all requirements for approval, and the state will implement and enforce a Class VI UIC program consistent with the Safe Drinking Water Act.
Environmental Justice Commitments in the Class VI Program
EPA is committed to incorporating safety and environmental burden considerations into all of our decisions in order to protect the health and well-being of all communities.
EPA has incorporated robust environmental justice commitments into the implementation of the Class VI program, including:
1. Environmental Justice Commitments Embedded in Louisiana’s Primacy Approval. EPA has included specific environmental justice provisions in the Memorandum of Agreement between EPA and Louisiana. These environmental justice commitments are now a clear benchmark for any state that seeks Class VI primacy in the future. The requirements include:
- An enhanced, inclusive public participation process.
- Consideration of environmental justice impacts on communities in permitting including environmental hazards, exposure pathways, as well as susceptible subpopulations.
- Incorporation of other mitigation measures to ensure Class VI projects do not increase environmental impacts and public health risks in already overburdened communities. Measures designed to protect residential areas could include carbon dioxide monitoring and release notification networks, and installation of enhanced pollution controls.
2. Letter to Governors. On December 9, 2022, Administrator Regan sent a letter to Governors outlining EPA expectations that all new primacy applications will contain a description of the state’s proposed approach for analyzing and addressing EJ and equity concerns.
3. Guidance to States and EPA Regions. On August 18, 2023, Assistant Administrator Fox released Environmental Justice Guidance for UIC Class VI Permitting and Primacy memorandum for addressing EJ concerns when overseeing primacy programs. The guidance is EPA’s operating framework for identifying, analyzing, and addressing EJ concerns in the context of implementing and overseeing all UIC permitting and primacy programs, including primacy approvals. The guidance outlines how states and regions should:
- Identify EJ communities.
- Enhance public involvement.
- Conduct appropriately scoped EJ assessments.
- Enhance transparency.
- Minimize adverse effects to underground sources of drinking water and communities they may serve.
4. Bipartisan Infrastructure Law Funding. Through the Bipartisan Infrastructure Law, EPA is providing over $48 million in grants that will support states, Tribes, and territories in developing and implementing UIC Class VI programs. As a condition of receiving funding, applicants to the new UIC Class VI grant program must demonstrate how environmental justice and equity considerations will be incorporated into their UIC Class VI primacy programs. Primacy program commitments may include identifying communities with potential environmental justice concerns, enhancing public involvement, developing appropriately scoped environmental justice assessments, enhancing transparency throughout the permitting process, and minimizing adverse effects associated with permitting actions.
EPA has developed a framework for conducting evaluations of states that are authorized to enforce and implement their own underground injection control (UIC) programs.