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On October 11, EPA promulgated changes to 40 CFR 63 Subpart MM, National Emission Standards for Hazardous Air Pollutants for Chemical Recovery Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills (Subpart MM). These changes were made as a result of the residual risk and technology review (RTR) for chemical recovery sources in the pulp and paper industry. Sources impacted by this rule include recovery furnaces, smelt dissolving tanks, and lime kilns at pulp and paper mills. 

While no emission standards were modified as a result of the RTR, subject facilities should be aware of several changes to monitoring, testing, reporting, and startup, shutdown and malfunction (SSM) provisions. Key changes to Subpart MM include: 

  • Revision of the opacity monitoring allowances for recovery furnaces and lime kilns equipped with electrostatic precipitators (ESPs);
  • New requirement to maintain proper operation of ESP automatic voltage control (AVC) systems;
  • Option to monitor scrubber fan amperage as an alternative to pressure drop for certain smelt dissolving tank scrubbers;
  • Removal of SSM exemptions and requirement to maintain an SSM plan;
  • Addition of language to clarify that emission standards apply at all times when spent pulping liquor or lime mud is fed (as applicable);
  • New requirement to conduct periodic performance testing every five years;
  • Addition of procedures for establishing operating limits based on data recorded by Continuous Parameter Monitoring Systems (CPMS);
  • Reduction of the frequency of excess emissions reports submission from quarterly to semiannually; and
  • New requirement to electronically submit performance test reports, semiannual reports, and notifications through EPA's Central Data Exchange (CDX) - Compliance and Emissions Data Reporting Interface (CEDRI).

ESP/Opacity Monitoring Changes

Under the December 2016 proposed rule, EPA had considered reducing the opacity limit for existing recovery furnaces from 35% to 20%, and additional parameter monitoring for recovery furnaces and lime kilns equipped with ESPs. Based on comments received on the proposal, EPA elected not to reduce the applicable opacity limit and is requiring proper operation of the ESP AVC system rather than additional monitoring.

40 CFR 63.864(k)(2) defines specific monitoring exceedances which constitute a violation of the emission standards under Subpart MM. Prior to the revision of Subpart MM, a violation of the emissions standard for recovery furnaces and lime kilns equipped with ESPs would occur when opacity exceeded a defined limit for more than 6% of operating time during each quarterly compliance period. This 6% opacity monitoring allowance has been reduced to 2% for recovery furnaces and 3% for lime kilns and will be assessed for each semiannual compliance period rather than for each quarterly compliance period.

New Electronic Reporting Requirements

Facilities should be aware of new electronic reporting requirements that will be implemented over time. Subpart MM performance test results must be entered into EPA's Electronic Reporting Tool (ERT). The ERT generates an output file, which is then uploaded to the CDX-CEDRI system for submittal. For semiannual excess emissions reporting for Subpart MM, EPA intends to create a spreadsheet reporting form which can be uploaded in CEDRI. EPA elected to develop a spreadsheet form rather than a web form or Extensible Markup Language (XML) form to allow for streamlined data entry.

Compliance Deadlines

The compliance date for existing sources under Subpart MM is October 11, 2019. The new source compliance date is October 11, 2017 or upon startup, whichever is later. The first periodic performance test for existing sources will be required by October 13, 2020. Electronic semiannual excess emissions reporting in CDX-CEDRI will be required one year after EPA makes the electronic reporting form available for use.

Next Steps

Owners and operators of existing units regulated by Subpart MM should consider completing a gap analysis of their present data acquisition systems related to startup and shutdown periods and the revised opacity monitoring allowances. Before implementing changes, a careful review of the facility's Title V permit is also warranted to determine if a Title V permit modification is necessary to incorporate the promulgated rule revisions. In addition, discussions with the regulatory authority regarding the timing of implementing changes is likely warranted. For example, one topic for discussion is whether facilities can transition to semiannual reporting prior to October 11, 2019 or would that be in violation of the prior quarterly reporting requirements per the original regulation.

The Federal Register publication for the proposed changes may be viewed here. For more information on the changes to Subpart MM, contact your local Trinity office at (800) 229-6655 or contact Mr. Chris Pool or Ms. Deanna Duram in Trinity's Atlanta Office.