An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

New Unit Set-aside Notices of Data Availability (NUSA NODA) For the Cross-State Air Pollution Rule

Units that are subject to the Cross-State Air Pollution Rule (CSAPR) but don't receive allowance allocations as existing units are eligible for a new unit set aside (NUSA) allowance allocation. NUSA allowance allocations are a batch of emissions allowances that are reserved for new units that are regulated by the CSAPR, but weren't included in the final rule allocations. The NUSA allowance allocations are removed from the original pool of regional allowances, and divided up amongst the new units, so as not to exceed the emissions cap set in the CSAPR.

Each calendar year, EPA issues two pairs of preliminary and final notices of data availability (NODAs), which are determined and recorded in two “rounds” and are published in the federal register.  In any year, if the NUSA for a given CSAPR state and program does not have enough new units after completion of the 2nd round, the remaining allowances are allocated to existing CSAPR-affected units.

Table:  Schedule of CSAPR NUSA NODAs by “Round”