SIP Proposal: Pennsylvania (reasonably available control technology determinations for Hydro Carbide Tool Company's case-by-case sources under the 1997 and 2008 eight-hour ozone NAAQS). 

EPA announced the availability of preliminary lists of units eligible for second-round allocations of emission allowances for the 2020 control periods from the new unit set-asides established under the Cross-State Air Pollution Rule trading programs. 

The Federal Highway Administration, Federal Railroad Administration, and Federal Transit Administration established regulations governing DOT's program for eliminating duplication of environmental reviews.

EPA lowered dust-lead clearance levels from 40 to 10 micrograms per square foot ^{for floors, and from 250 to 100 micrograms per square foot for window sills.}

DOT adjusted civil penalty amounts that may be imposed for violations of certain Department regulations pursuant to the Federal Civil Penalties Inflation Adjustment Act Improvements Act.

The Natural Resources Conservation Service adopted an interim rule published in the Federal Register on February 13, 2020, that implements changes to the Regional Conservation Partnership Program necessitated by the Agriculture Improvement Act of 2018.

SIP Proposal: Kansas (removal of Reid vapor pressure fuel requirement in Kansas City).

NOAA proposed a non-substantive correction to its January 2021 designation of critical habitat for the Beringia distinct population segment of the bearded seal.

SIP Proposal: Delaware (amendments to mobile equipment repair and refinishing regulations for volatile organic compounds).

SIP Proposal: Pennsylvania (maintenance plan for the 1997 eight-hour ozone NAAQS in the Clearfield/Indiana area).