Is your state making the air worse in another — what the good neighbor provision asks of every state
The Environmental Protection Agency proposed approving a state implementation plan revision from Mississippi. The Clean Air Act requires each state to show in its plan that its own emissions do not prevent other states from meeting the standards.
Document overview (primary data)
- Document typeProposed rule
- AgencyEnvironmental Protection Agency
- Citation91 FR 55305
Key points
- The Environmental Protection Agency proposed approving a Mississippi plan revision as meeting the good neighbor provision.
- The provision requires each state plan to prohibit interstate transport of pollution that would significantly affect other states.
- The agency proposes to determine that Mississippi does not affect attainment of the 2010 sulfur dioxide standard in any other state.
- Even a conclusion of no effect requires submission, review, a proposed determination and a comment period.
- The state submitted on January 27, 2022 and the proposed approval came on August 27, 2026, more than four years later.
1What does not stop at a border
Air pollution knows nothing of administrative boundaries. Material leaving a facility in one state can ride the wind and worsen the air next door, and a downwind state may then fail the standard however tightly it regulates its own sources. The Clean Air Act places an obligation on every state for this.
What is required is assurance, in the plan, of not contributing significantly to nonattainment in another state or interfering with maintenance there. A plan written with only the home state in mind does not suffice.
2Even a finding of no interference is reviewed
- 1The state submitsA plan showing its emissions do not affect other states
- 2The agency reviewsThe submission is examined
- 3A determination is proposedHere, that the state neither contributes significantly nor interferes with maintenance
- 4Approval is proposedOn that determination, the plan is proposed for approval as meeting the requirement
Worth noting is that a conclusion of no effect still passes through open procedure. Reaching the result that nothing more need be done takes submission, review, a proposed determination and a comment period. This site also covers negative declarations, where the absence of any regulated facility is itself certified — the same structure of confirming an absence through procedure.
3Four years from submission
The revision was submitted January 27, 2022 and the proposed approval published August 27, 2026, more than four years later. Another air plan approval this site covers also took four years from submission to approval, which conveys the timescale in this field. A state filing a plan does not settle matters quickly.
4Why sulfur dioxide differs
The subject here is sulfur dioxide, arising mainly from combustion of fossil fuels, with large power plants and factories as the principal sources. Because those sources are comparatively large and concentrated, interstate transport can be examined by tracing particular facilities. That differs from a pollutant like ozone, whose sources are spread thin and wide.
Why it matters
Because pollution crosses borders, regulation does not close within a state. For pollutants whose sources are large and concentrated, interstate transport is traced to particular facilities, making the siting of large plants a multi-state question.
FAQ
What is the good neighbor provision?
Is procedure needed even where there is no effect?
Sources (primary)
Source: Federal Register (federal documents, public domain). Links go to the official site.