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Frequent Questions about the Final Rule: Additions to List of Categorical Non-Waste Fuels

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Question: Why did EPA finalize categorical additions to the Non-Hazardous Secondary Materials (NHSM) Rule?

Answer: In the February 7, 2013 NHSM rule, EPA listed particular NHSMs as “categorical” non-waste fuels. Persons burning categorical non-wastes do not need to evaluate them under the general case-by-case standards and procedures that would otherwise apply to NHSMs used in combustion units. In the rule, EPA also indicated that it would consider adding additional NHSMs to the list of materials that are considered categorical non-wastes and identified several materials that would be good candidates for a future rulemaking.

The materials addressed in the 2016 final categorical rule have been mentioned in previous NHSM rulemakings. The February 2013 final NHSM rule noted that paper recycling residuals and construction and demolition debris processed pursuant to best practices would be good candidates to be listed at a categorical non-waste fuel. Furthermore, EPA identified creosote-treated railroad ties in the February 2013 final rule as a potential candidate for a categorical non-waste listing. EPA evaluated these three materials to see if they meet the criteria for a categorical listing. The 2016 final categorical rule defines the criteria needed to be met in order for the materials to be considered NHSM categorical non-waste fuels.

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Question: What materials are included in the 2016 final rule?

Answer: Based on all available information, the EPA determined that the following NHSMs are not solid wastes when burned as a fuel in combustion units and listed them as categorical non-wastes under section 241.4(a):

  • Construction and demolition (C&D) wood processed from C&D debris according to best management practices;
  • Paper recycling residuals generated from the recycling of recovered paper, paperboard and corrugated containers and combusted by paper recycling mills whose boilers are designed to burn solid fuels; and
  • Creosote-treated railroad ties that are processed and then combusted in the following types of units. (i) Units designed to burn both biomass and fuel oil as part of normal operations and not solely as part of start-up or shut down operations, and (ii) Units at major source pulp and paper mills or power producers subject to 40 CFR 63 Subpart DDDDD that had been designed to burn biomass and fuel oil, but are modified (e.g. oil delivery mechanisms are removed) in order to use natural gas instead of fuel oil as part of normal operations and not solely as part of start-up or shut down operations. See Q/A below for additional discussion on units that switched to natural gas.

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Question: What is the additional approach being adopted for CTRTs?

Answer: The Agency is adopting the additional approach outlined in the proposed rule with some revisions. As indicated in the previous question and answer, based on comments received and information in the rulemaking record, the Agency has sufficient information to list as a categorical non-waste CTRTs that were combusted in units at major pulp and paper mills or power producers subject to 40 CFR Part 63 Subpart DDDDD (Boiler MACT) that had been designed to burn biomass and fuel oil, but are modified (e.g., oil delivery mechanisms are removed) in order to use natural gas as part of normal operations instead of fuel oil. These CTRT can continue to be combusted as product fuel only if certain conditions are met, which are intended to ensure that the CTRTs are not being discarded:

  • CTRTs must be burned in an existing (i.e. commenced operation prior to April 14, 2014) stoker, bubbling bed, fluidized bed, or hybrid suspension grate boilers; and
  • CTRTs can comprise no more than 40 percent of the fuel that is used on an annual heat input basis.

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Question: What are the best management practices required for C&D wood under this rule?

Answer: Best management practices for purposes of this categorical listing must include sorting by trained operators that excludes or removes the following materials from the final product fuel: non-wood materials (e.g., polyvinyl chloride and other plastics, drywall, concrete, aggregates, dirt, and asbestos), and wood treated with creosote, pentachlorophenol, chromated copper arsenate, or other copper, chromium, or arsenical preservatives. There are also best management practices for positive and negative sorting, training and written certification discussed below.
Positive sorting is where operators pick out desirable wood from co-mingled debris. C&D processing facilities that use positive sorting or that receive and process positive sorted C&D wood must either:

  • exclude all painted wood (to the extent that only de minimis quantities inherent to process limitations may remain) from the final product fuel,
  • use X-ray Fluorescence to ensure that painted wood included in the final product fuel does not contain lead-based paint, or
  • require documentation that a building has been tested for and does not include lead-based paint before accepting demolition debris from that building.

Negative sorting is where operators remove contaminated or otherwise undesirable materials from co-mingled debris. C&D processing facilities that use negative sorting must remove fines (e.g., small-sized particles that may contain relatively high concentrations of lead and other contaminants) and either

  • remove all painted wood (to the extent that only minimal quantities inherent to process limitations may remain),
  • use X-ray Fluorescence to detect and remove lead-painted wood, or
  • require documentation that a building has been tested for and does not include lead-based paint before accepting demolition debris from that building.

Processors must train operators to exclude or remove the materials identified above from the final product fuel. Records of training must include the date the training was held and must be maintained on-site for a period of three years.

For every new or modified contract, purchase agreement, or other legally binding document, a written certification must be obtained by the combustor from each final processor of C&D wood and must include the statement "the processed C&D wood has been sorted by trained operators in accordance with best management practices."

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Question: In general, what is the purpose of the 2016 NHSM rule?

Answer: The NHSM rule establishes standards and procedures for identifying whether non-hazardous secondary materials are solid wastes when used as fuels or ingredients in combustion units. If material is a solid waste under the Resource Conservation and Recovery Act (RCRA), a combustion unit burning it is required to meet the Clean Air Act (CAA) section 129 emission standards for solid waste incineration units. If the material is not a solid waste, combustion units are required to meet the CAA section 112 emission standards for commercial, industrial, and institutional boilers.

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Question: How does the 2016 NHSM rule impact the regulated community?

Answer: These categorical listings make it easier to comply with the NHSM regulations, as persons that generate or burn these NHSMs will not need to make individual determinations on these materials regarding their waste status. This action demonstrates the Agency’s commitment to consider adding additional NHSMs to the categorical listings and reflects the Agency's overall commitment to advance sustainability objectives in its actions.

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Question: Regarding sources combusting C&D wood, PRRs and CTRT in boilers subject to the January 31, 2016 Boiler MACT compliance deadline, how do such sources determine the status of these materials under NHSM standards between that deadline and the effective date of this final categorical rule?

Answer: In the time period between the January 31, 2016 Boiler MACT compliance deadline and the March 9, 2016 effective date of the final categorical NHSM rule, combustors may, as is allowed under the existing regulations at 40 CFR 241.3(b)(4)  make their own determinations as to the status of their material. In order to be considered a non-waste fuel under that section, a source combusting these materials must ensure the appropriate regulatory criteria for combustion of discarded NHSMs are met. Information contained in the February 8, 2016 final rule is useful in making those determinations (see 81 FR 6688).

If a source combusting these materials cannot make this determination, it may burn the fuel under solid waste incineration standards issued under Clean Air Act section 129.

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Question: How is the Agency addressing other types of treated railroad ties under the NHSM rules?

Answer: An August 21, 2015 letter from the Treated Wood Council requested that the Agency move forward quickly regarding a categorical non-waste determination on creosote borate, copper naphtenate, and copper naphtenate-borate treated railroad ties. In the letter, TWC indicated that these types of ties are increasingly being used as alternatives to creosote treated ties, and that the ability to reuse the ties is an important consideration in rail tie purchasing decisions.

The Agency reviewed TWC information on the three treated railroad ties, creosote borate, copper naphtenate, and copper naphtenate-borate, submitted on September 11, 2015 and requested additional contaminant data which was submitted on October 5, 2015 and October 19, 2015. Based on information provided to the Agency to date, we believe these three treated railroad ties are candidates for categorical non-waste listings and expect to begin development of a proposed rule under 40 CFR 241.4(a) regarding those listings in the near future.

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