Plant-Wide Applicability Limit (PAL)

What is PAL?

A Plantwide Applicability Limit (PAL) is a pollutant-specific annual emissions cap applied across all emission sources at a major stationary source based on actual historical emissions rather than theoretical maximums. PALs offer a flexible alternative to the traditional New Source Review (NSR) process by allowing facilities to make operational changes without triggering major modification permitting. Facilities are allowed to modify operations, install new equipment, or expand capacity as long as they remain under their PAL threshold. Key features of a PAL include:

• • Applicable in both attainment and nonattainment areas
  • Based on actual emissions, not potential-to-emit (PTE) projections
  • Valid for a 10-year term, with renewal options
  • Managed using a 12-month rolling total emissions tracking approach

Who Should Consider a PAL?

Plantwide Applicability Limits (PALs) are ideal for major stationary sources that experience frequent operational changes and want to avoid complex NSR permitting processes. The key differences between traditional NSR and PAL are:

1. 1. Review Scope
      1. Traditional NSR – Project by project
      2. PAL – Facility wide
   2. Emissions Basis
      1. Traditional NSR – Potential to emit
      2. PAL – Actual historic emissions
   3. Trigger
      1. Traditional NSR – Significant project increases
      2. PAL – Exceeding PAL cap

Facilities that benefit the most from PAL are ones with:

• • Sites with recurring expansions, operation shifts, or upgrade
  • Facilities with tight project timelines
  • Sources that want to avoid repeated Best Available Control Technology (BACT) or Lowest Achievable Emission Rate (LAER) evaluations
  • Companies seeking more control over emissions strategy across the plant

How is a PAL Determined? (PAL Calculation)

A PAL is calculated through a unit-specific analysis using a defined 24-month baseline period selected within the past 10 years. The PAL represents the facility-wide cap based on actual historical emissions with adjustments for new, modified, or shutdown emissions units.

PAL Emissions Limit Formula:

PAL = ∑ Baseline Actual Emissions (existing units) + ∑ Potential to Emit (new units) – Actual Emissions (shutdown units) + Significant Emission Level (per pollutant)

PAL Application & Monitoring Key Requirements

To establish a Plantwide Applicability Limit (PAL), facilities must submit a complete application that demonstrates the ability to reliably track and comply with a 12-month rolling total emissions cap. Key components of the PAL application include:

1. 1. Emission Inventory – List all emissions units at the facility, classified by their potential to emit PAL pollutant:
      1. Small Unit – Emits or has potential less than significant threshold for PAL
      2. Significant Unit – Emits at or above significant level but below major source threshold
      3. Major Unit – Emits or has the potential to emit 100 tons/year or more in attainment areas
   2. Applicable Requirements – Identify all federal and state requirements, emission limits, and work practices applicable to each unit
   3. Baseline Emission Calculations – Provide 24-month baseline of actual emissions for each unit, selected from past 10 years
   4. Monitoring Plan – Outline methods for monthly tracking and calculating annual emissions using approved monitoring technologies, which include:
      1. Mass Balance Calculations (for coating/solvent use)
      2. Continuous Emissions Monitoring Systems (CEMS)
      3. Continuous Parameter Monitoring System (CPMS) or Predictive Emissions Monitoring System (PEMS)
      4. Validated Emission Factors

PAL Lifecycle Management

PALs operate on a 10-year term and must be actively maintained through proper tracking, recordkeeping, and proactive management.

1. PAL Renewal

PALs must be renewed every 10 years. A timely renewal application must be submitted:

• • At least 6 months before expiration
  • No earlier than 18 months before expiration

Renewal applications include updated emissions data, revised monitoring details, and a proposed PAL level.

2. PAL Reopening

A PAL must be reopened by the permitting authority to:

• • Correct typographical/calculation errors
  • Incorporate enforceable emissions reductions used as offsets
  • Reflect increase in PAL

The permitting authority may reopen the PAL permit to:

• • Reduce PAL to reflect newly applicable federal requirements (e.g. New Source Performance Standards)
  • Reduce PAL to align with any other requirements imposed on facility
  • Reduce PAL if determined that reduction is necessary to prevent violation of the National Ambient Air Quality Standard (NAAQS) or to avoid exceeding a Prevention of Significant Deterioration (PSD) increment

3. Increasing PAL

To increase PAL during its effective term, facilities need to:

1. 1. Submit a complete application with justification for increase
   2. Demonstrate that new/modified units would exceed the current PAL level
   3. Conduct a BACT/LAER analysis
   4. Obtain major NSR permits for contributing units, regardless of magnitude of emissions increase

4. Terminating PAL

A facility may request to terminate its PAL before expiration. The process follows:

1. 1. Termination Request
   2. Permitting Authority Action
      1. Establish new unit-specific allowable limits
      2. Revert facility to standard NSR applicability for future modifications
   3. Facility Compliance – Facility must continue to comply with existing PAL emissions limits until new limits are finalized

Staying Ahead of PALs

While Plantwide Applicability Limits (PALs) are an optional permitting approach, they offer an efficient alternative for facilities seeking to streamline air permitting, reduce regulatory delays, and gain greater control over their emissions profile. For major sources undergoing frequent operational changes, a PAL can eliminate the need for project-specific NSR permitting and simplify long-term planning. Our SEC experts work closely with facilities to identify strategic permitting pathways that align with your operational goals.

Want to dive deeper into strategic considerations and EPA’s latest PAL clarifications? Check out SEC’s New Insights into Plantwide Applicability Limit (PAL).