Progress Report

Program Compliance

Compliance for the Acid Rain Program (ARP) and each of the Cross-State Air Pollution Rule (CSAPR)1 trading programs is assessed on an annual basis. Each regulated facility must hold an amount of allowances equal to or greater than its emissions for the relevant compliance period. Historically, these programs have had exceptionally high rates of compliance. This performance continued in 2021 as 100% of the facilities in each of these programs held sufficient allowances to cover their emission obligations.

The information below details how the ARP and CSAPR allowances were used for compliance under the emissions trading programs in 2021. In contrast to the ARP and CSAPR,1 the Mercury and Air Toxics Standards (MATS) rule is issued under section 112 of the Clean Air Act and is not an emissions trading program.


  1. CSAPR refers to the CSAPR, the CSAPR Update, and the Revised CSAPR Update programs.

Program Compliance Tables

SO₂ Compliance Summary
ARP SO₂ Program Allowance Reconciliation Summary, 2021
Annual SO₂ Group 1 Allowance Summary
CSAPR SO₂ Group 1 Program Allowance Reconciliation Summary, 2021
Annual SO₂ Group 2 Allowance Summary
CSAPR SO₂ Group 2 Program Allowance Reconciliation Summary, 2021
Annual NOₓ Allowance Summary
CSAPR NOₓ Annual Program Allowance Reconciliation Summary, 2021
NOₓ Ozone Season Group 1 Allowance Summary
CSAPR NOₓ Ozone Season Group 1 Program Allowance Reconciliation Summary, 2021
NOₓ Ozone Season Group 2 Allowance Summary
CSAPR NOₓ Ozone Season Group 2 Program Allowance Reconciliation Summary, 2021
NOₓ Ozone Season Group 3 Allowance Summary
CSAPR NOₓ Ozone Season Group 3 Program Allowance Reconciliation Summary, 2021