Citizen Group Petition Prompts DEP Rulemaking to Reduce Greenhouse Gas Emissions

On April 25, 2018 the Maine Department of Environmental Protection (DEP) initiated a rulemaking based on a citizen petition to adopt new rules establishing emissions standards and to modify ten existing rules governing emissions of greenhouse gases (GHGs) in the state of Maine. While Maine has focused GHG emissions reduction regulations on large power plants through the Regional Greenhouse Gas Initiative (RGGI) program, the recent proposal would significantly expand the scope of the state’s GHG reduction requirements to include continuous emissions monitors for CO2 emissions from any potential emission unit and to require Part 70/Title V sources to develop enforceable CO2 reduction plans.  

The rules proposed would establish emissions standards for (1) GHG emissions from stationary sources; and (2) sulfur hexafluoride (SF6 - a greenhouse gas) from gas-insulated switchgear operators. 

The proposed “Greenhouse Gas Emission Standards” rule would establish a statewide GHG emission limit for each year beginning in 2020, and would require submission of GHG emission reduction plans for certain stationary sources and vehicle fleets. The crux of the proposed rule is GHG emission reductions of at least 8% each year, which would result in Maine reducing its GHG emissions to approximately 75-85% below 2003 levels by the year 2035. To achieve that statewide limit, the proposed rule calls for DEP to establish minimum facility-wide GHG emission limits, in tons per year carbon dioxide equivalents (CO2e), for various emission source categories.

The proposed “Sulfur Hexaflouride Emissions Standards” rule would largely apply to any gas-insulated switchgear owner, and sets maximum annual SF6 emissions rates which decrease from 3.5% in 2019 to 1.0% in 2024 and each year thereafter.

DEP’s rulemaking also includes proposed amendments to ten existing rules to incorporate GHG standards and cross-reference the proposed new Greenhouse Gas Emission Standards rule. In brief, those proposed amendments are as follows:

  • Chapter 117: Source Surveillance. Amendment to require owners or operators of any emission unit with the potential to emit GHGs to continuously monitor those emissions.
  • Chapter 121: Emission Limitations and Emission Testing of Resource Recovery Facilities. Amendment to apply emission limits for GHGs or CO2e to large municipal waste combustor units.
  • Chapter 137: Emission Statements. Amendment to include CO2e among those GHGs that trigger application of the regulation to stationary sources, and to revise the definition of GHGs to include any gas subject to emission standards under the new Greenhouse Gas Emission Standards rule.
  • Chapter 140: Part 70 Air Emission Licensing Regulations. Amendment to require inclusion of a plan to reduce GHGs to a level in compliance with the New Greenhouse Gas Emission Standards in Part 70 license application materials, and to allow the DEP to include limits on the emission of any GHGs as a license term.
  • Chapter 146: Diesel-Powered Motor Vehicle Emissions Standards. Amendment to define CO2e, and to include undefined emission levels of CO2e for diesel-powered motor vehicles for certain model years.
  • Chapter 148: Emissions from Smaller-Scale Electric Generating Facilities. Amendment to include undefined GHG emission standards for non-emergency generators.
  • Chapter 150: Control of Emissions from Outdoor Wood Boilers. Amendment to include an undefined amount of CO2e emissions among the prohibitions for all outdoor wood and pellet boilers.
  • Chapter 164: General Permit for Concrete Batch Plants. Amendment to subject owners and operators of concrete batch plants to the requirements of the new Greenhouse Gas Emission Standards.
  • Chapter 165: General Permit for Class IV-A Incinerators. Amendment to include the new Greenhouse Gas Emission Standards in the Class IV-A Incinerator general permit conditions and requirements, and to require that GHG emissions from the incinerator not exceed a limit of CO2e to be determined by the DEP.
  • Chapter 305: Natural Resources Protection Act Permit by Rule Standards. Amendment to prohibit issuance of a permit by rule if the proposed activity will result in emissions of GHGs in excess of an undefined amount.

Note that for Chapters 146, 148, 150, and 305, the proposed amendments include language establishing emission limits for GHGs, but do not establish actual numerical limits.

The DEP has stated that it is unable to perform a formal benefit/cost analysis on these proposals, but it anticipates that the proposed rules and amendments would have a wide range of fiscal impacts across multiple industries, and likely will result in increased environmental compliance costs due to the need for operational changes, re-engineering, fuel switching, and/or equipment upgrades. 

There will be a public hearing on the rulemaking on May 15, 2018 at 1:00 PM in Augusta. Comments on the rulemaking are due June 29, 2018. If you have any questions about the proposal or participation in the rulemaking process, please contact Lisa Gilbreath at 207.791.1397 or