The Environmental Protection Agency (EPA) is proposing a rule that would reduce air pollution from highway heavy-duty vehicles and engines, including ozone, particulate matter, and greenhouse gases. This proposal would change the heavy-duty emission control program-- including the standards, test procedures, useful life, warranty, and other requirements--to further reduce the air quality impacts of heavy- duty engines across a range of operating conditions and over a longer period of the operational life of heavy-duty engines.

The Environmental Protection Agency (EPA) is approving the Clean Air Act State Plan revisions for Large Municipal Waste Combustors (MWCs) submitted by the Massachusetts Department of Environmental Protection (MassDEP) on December 18, 2018. The revised State Plan is in response to amended emission guidelines (EGs) for Large MWCs promulgated on May 10, 2006. MassDEP's State Plan is for implementing and enforcing provisions at least as protective as the EGs applicable to existing Large MWCs. This action is being taken under the Clean Air Act.

The Environmental Protection Agency (EPA) is proposing to approve the Clean Air Act (CAA) state plan revision for existing large and small municipal waste combustors (MWCs) submitted by the New Hampshire Department of Environmental Services (NHDES) on October 1, 2018. The revised state plan incorporates wood residue combustion fuel quality standards and test methods at MWC facilities that process and combust construction and demolition debris.

The Environmental Protection Agency (EPA) is approving a Clean Air Act (CAA or the ``Act'') section 111(d) state plan submitted by the North Dakota Department of Environmental Quality (NDDEQ or the ``Department'') on July 28, 2020 for the control of air pollutants from existing municipal solid waste (MSW) landfills. The EPA is also approving a CAA section 111(d)/129 state plan submitted by the Department on the same date for the control of air pollutants from existing commercial and industrial solid waste incineration (CISWI) units and air curtain incinerator (ACI) units.