EPA finalizes emission standards for large municipal waste combustors

On March 10, 2026, the Environmental Protection Agency (EPA) finalized emission regulations for large municipal waste combustors (LMWCs). The final rule revises nearly all emission limits for new and existing LMWCs.

Who’s impacted?

The final rule applies to LMWCs that combust more than 250 tons per day of municipal solid waste and are covered by the:

• New Source Performance Standards (NSPS) for new LMWCs, or
• Emission Guidelines (EGs) for existing LMWCs.

EPA established new subparts for the amendments at 40 CFR Part 60, including:

• Subpart VVVV for the NSPS, and
• Subpart WWWW for the EGs.

What are the changes?

Generally, stricter emission limits apply. For all LMWCs (new and existing), the rule revises the emission limits for:

• Cadmium,
• Hydrogen chloride,
• Lead,
• Mercury,
• Particulate matter,
• Polychlorinated dibenzodioxins and dibenzofurans, and
• Sulfur dioxide.

For all new LMWCs, the final rule revises the emission limits for carbon monoxide (CO) and nitrogen oxides (NO_x). The final rule also amends the CO and NO_x limits for all existing LMWCs, except for the CO limits for two subcategories of combustors and the NO_x limits for two subcategories of combustors for new municipal solid waste incinerators.

Other major changes include:

• Removing certain exclusions and exemptions for startups, shutdowns, and malfunctions (requiring LMWCs to meet emission standards at all times);
• Removing the NOx emissions averaging compliance alternative for existing LMWCs;
• Amending recordkeeping and reporting requirements; and
• Eliminating Title V operating air permit requirements for qualifying air curtain incinerators that burn only wood waste, yard waste, and clean lumber.

What’s the compliance timeline?

When EPA updates EGs, states must revise their State Implementation Plans (SIPs) to incorporate the changes. States have to submit revised SIPs by March 10, 2027. Once EPA approves the SIP, facilities with existing LMWCs must meet the new standards either within 3 years of the SIP’s approval date or by March 10, 2031, whichever is earlier.

New LMWCs must comply with the amended NSPS by September 10, 2026, or upon startup, whichever is later.

Key to remember: EPA finalized stronger emission limits for new and existing large municipal waste combustors and made other changes to the standards.