The Maine Department of Environmental Protection (MDEP) is proposing changes to their Visible Emissions regulations in order to comply with a recent SIP call issued by the EPA. Chapter 101 was last updated in 2003 and includes up to two six-minute emissions exceedance exceptions per each three-hour period. These exemptions were found to violate the Clean Air Act (CAA). The changes currently being proposed are meant to rectify this issue while also allowing sites the flexibility to accommodate for unavoidable fluctuations in regular operations. The proposed changes include the following:

  • Removal of the "unregulated" exemption periods and inclusion of new, alternate provisions for periods of startup, shutdown, or malfunction, allowing the option of compliance with work practice standards to minimize emissions during such times instead of a numerical opacity limit.
  • Clarification of exemptions from the Chapter, including units whose visible emissions are regulated through another State rule, visible air contaminants emitted for the purpose of visible emissions observer training, and visible air contaminants emitted for the purpose of Predictive Emission Monitoring Systems (PEMS) research that has been approved by the Commissioner and EPA
  • Clarification of the applicability of the annual capacity factor visible emission standard. - Inclusion of a definition of distillate fuel, for the purposes of the Chapter.
  • Removal of specific visible emissions standards for Kraft recovery furnaces, since all such units are subject to visible emission standards in applicable federal rules.

If you have any questions on the proposed rule changes please contact Kristine Davies, Principal Consultant of our Boston Office at (508) 273-8600, ext 2701.