What Is State Primacy? Delegated EPA Programs and Requirements

State primacy is the arrangement under which the Environmental Protection Agency delegates a federal environmental program to a state government, so that state officials run the permitting, inspections, and enforcement that would otherwise sit with the EPA. The trade is straightforward: a state gets to tailor a program to local conditions, and in exchange its rules can never fall below the federal floor. The most familiar example is drinking water, where 49 of the 50 states hold primacy under the Safe Drinking Water Act; only Wyoming and the District of Columbia remain under direct EPA enforcement.¹

Primacy is program-specific. A state can hold it under one statute and not another, and each federal law has its own delegation rules, its own prerequisites, and its own path to approval.

Which Federal Programs Can Be Delegated

Five programs account for most state primacy activity: drinking water, wastewater permitting, hazardous waste, air quality, and underground injection control.

Safe Drinking Water Act

A state gains primary enforcement responsibility by adopting drinking water regulations at least as protective as the federal standards, maintaining enforcement procedures, and showing it can respond to emergencies like floods and contamination events.² This is the most widespread form of primacy, covering public water systems of every size.

Clean Water Act Discharge Permits

Section 402 of the Clean Water Act lets a state governor submit a program description and an attorney general’s statement of legal authority to administer discharge permits for facilities releasing pollutants into waterways. The EPA must approve the program unless it finds the state lacks authority to issue fixed-term permits, ensure public notice and hearings, or enforce compliance through inspections and monitoring.³ Once approved, state-issued permits become federally enforceable.

Hazardous Waste Under RCRA

A state running its own hazardous waste program must show the program is equivalent to the federal one, consistent with programs in other states, and backed by adequate enforcement. The EPA has 90 days after receiving an application to signal whether it expects to approve, followed by another 90-day window with a public hearing before it issues a final decision.⁴

Clean Air Act State Implementation Plans

Air quality works differently because participation is effectively mandatory. After the EPA sets a national ambient air quality standard, each state must adopt and submit a State Implementation Plan within three years, laying out how it will achieve and maintain that standard through enforceable emission limits, monitoring systems, and permitting for new or modified pollution sources.⁵ If the state does not submit a plan or the EPA disapproves one, the EPA writes and imposes a Federal Implementation Plan instead.⁶

Underground Injection Control

The Safe Drinking Water Act also covers wells that inject fluids underground, from disposal wells to Class VI wells used for carbon sequestration. States apply under Section 1422 (all well classes) or Section 1425 (Class II oil-and-gas wells only) by showing they meet minimum federal requirements and have the enforcement tools to protect underground drinking water sources.⁷

What a State Must Prove to Qualify

Every primacy program shares three prerequisites: strong enough laws, real enforcement authority, and the operational capacity to run the program day to day.

Rules at Least as Strict as Federal Standards

The foundational requirement is regulatory stringency. Under the Safe Drinking Water Act, state regulations must be “no less stringent” than national primary drinking water regulations, and the state must adopt them within two years of the federal rule’s publication.² Under RCRA, the state hazardous waste program must be “equivalent” to and “consistent” with the federal program.⁴ States are free to go further, never less.

Enforcement Authority With Real Penalties

A state must show it has civil and criminal enforcement tools, including the ability to impose meaningful financial penalties. For drinking water systems serving more than 10,000 people, the state’s administrative penalties must be at least $1,000 per day per violation.² State penalty caps do not have to match the federal numbers, which are adjusted annually for inflation, but they have to bite.

Capacity to Run the Program

Paper authority is not enough. States must adopt an adequate plan for providing safe drinking water during emergencies, including earthquakes, floods, and hurricanes.² They also have to maintain an inventory of every regulated system, run a systematic sanitary survey program that prioritizes systems out of compliance, and ensure access to certified laboratories that can test for all regulated contaminants.⁸ Inspectors, lab capacity, legal staff, and data analysts all have to be in place. Funding usually comes from a mix of federal grants and permitting fees.

How the Application Works

Meeting the prerequisites is only half the job. The state has to assemble a formal application and survive a multi-stage federal review.

The exact package varies by program, but underground injection control applications illustrate the standard elements: a governor’s letter requesting approval, a narrative program description, an attorney general’s statement certifying legal authority, a Memorandum of Agreement with the EPA, copies of all relevant state statutes and regulations, and documentation of a public participation process.⁷ The attorney general’s certification is not a formality: it must link specific provisions of state law to the corresponding federal requirements. The Memorandum of Agreement governs the ongoing relationship, spelling out how the state will administer the program, what it will share with the EPA, and how the two will coordinate on enforcement. Without a signed MOA, no primacy transfer moves forward.

Once the regional EPA office determines the application is complete, it must provide public notice and at least 30 days for comment. If there is significant interest or a formal request, the EPA or the state must hold a public hearing. The final decision is published in the Federal Register, and the effective date in that notice marks the formal transfer of authority.⁹ Conditional approval is possible when the EPA finds only minor deficiencies, letting the state take on primacy while fixing specific items within a set timeframe.

Ongoing Obligations After Primacy Is Granted

Delegation is not permission to regulate at leisure. It comes with enforceable obligations that the EPA audits regularly.

State inspectors conduct routine site visits, check equipment, review internal records, and verify that monitoring samples are being collected on schedule and analyzed at certified labs. Failed inspections trigger a notice of violation specifying corrective action; ignoring that notice escalates to formal enforcement.

States must also keep the program current. Every time the EPA promulgates a new or revised regulation, primacy states have to update their programs in step. Under 40 CFR 142.12, a state has two years from the date a new drinking water rule is published to submit a complete program revision, with the option of a two-year extension if requested before the original deadline expires.¹⁰ Until a state formally adopts a revised rule and receives primacy for it, the EPA retains primary enforcement authority for that specific regulation, even in states that hold primacy for everything else.¹¹

Data reporting is not optional. States feed compliance data into federal systems so the EPA can monitor national program performance without managing individual facilities.¹² A state that falls behind on data entry is effectively hiding its program’s performance from federal reviewers.

How Primacy Can Be Overridden or Lost

Primacy does not eliminate federal authority. It layers state authority on top, and both the EPA and private citizens keep power to intervene when state oversight falls short.

EPA Overfiling

Under Section 1414 of the Safe Drinking Water Act, when the EPA discovers a public water system violating federal standards in a primacy state, it notifies the state and the system. If the state fails to begin enforcement within 30 days, the EPA can issue its own administrative order or file a civil lawsuit. The EPA also retains independent enforcement authority even after a state obtains primacy for a revised regulation.¹¹

Citizen Suits

Federal environmental statutes give private citizens a backstop. Under the Clean Water Act, any person can file a federal lawsuit against a facility violating an effluent standard or permit condition, or against the EPA administrator for failing to perform a mandatory duty. The Safe Drinking Water Act contains a parallel provision. In both cases, the plaintiff must give 60 days’ written notice to the alleged violator, the EPA, and the relevant state before filing. If the government is already diligently prosecuting the violation, the citizen suit is blocked, though the citizen can intervene in the government’s case.¹³ A slow-moving primacy state exposes violators to private lawsuits as well as EPA action.

Withdrawal of Primacy

Rescinding a state’s primacy is the last resort, and it follows a formal process. The EPA reviews each primacy state’s program at least once a year. If the review reveals the state no longer meets delegation requirements, the EPA must notify the state in writing and summarize the deficiencies. The state has 30 days to submit evidence showing it still qualifies. If that response is inadequate or never comes, the EPA issues a final determination that primacy is withdrawn. A state can also give up primacy voluntarily by notifying the EPA in writing at least 90 days before the intended effective date.¹⁴ Either way, regulatory and enforcement power reverts to the EPA, the state must transfer its records, and regulated facilities move to direct federal oversight.

A Note on Tribal Authority

State primacy applies to states. Federally recognized Indian tribes can obtain comparable authority through a separate process called Treatment as a State, or TAS. Under Section 518 of the Clean Water Act, the EPA may treat an eligible tribe as a state for purposes of water quality standards, discharge permitting, and other regulatory programs, provided the tribe’s governing body carries out substantial governmental duties, the functions relate to water resources within the reservation, and the tribe can reasonably carry out those functions consistent with the statute.¹⁵ TAS is program-specific, and the Safe Drinking Water Act similarly allows tribes to seek primacy over drinking water systems on tribal lands under the same general requirement that tribal regulations meet or exceed federal standards.⁸

1
US EPA. Primacy Agency Drinking Water Data
2
Office of the Law Revision Counsel. 42 U.S. Code 300g-2 – State Primary Enforcement Responsibility
3
Office of the Law Revision Counsel. 33 USC 1342 – National Pollutant Discharge Elimination System
4
Office of the Law Revision Counsel. 42 USC 6926 – Authorized State Hazardous Waste Programs
5
Office of the Law Revision Counsel. 42 USC 7410 – State Implementation Plans for National Primary and Secondary Ambient Air Quality Standards
6
US EPA. Basic Information about Air Quality SIPs
7
US EPA. Primary Enforcement Authority for the Underground Injection Control Program
8
eCFR. 40 CFR 142.10 – Requirements for a Determination of Primary Enforcement Responsibility
9
Environmental Protection Agency. Procedure for Review of State Primacy Applications
10
eCFR. 40 CFR 142.12 – Revision of State Programs
11
U.S. Environmental Protection Agency. Compliance Advisory – Failure to Comply with Certain New Safe Drinking Water Act Lead and Copper Rule Requirements May Result in Federal Enforcement
12
Environmental Protection Agency. Safe Drinking Water Information System Overview
13
Office of the Law Revision Counsel. 33 USC 1365 – Citizen Suits
14
eCFR. 40 CFR 142.17 – Review of State Programs and Procedures for Withdrawal of Approved Primacy Programs
15
Office of the Law Revision Counsel. 33 USC 1377 – Indian Tribes