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Frequent Questions About the Proposed Rule on Additions to the List of Categorical Non-Waste Fuels: Other Treated Railroad Ties

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What materials are included in the 2016 proposed rule?

EPA is proposing that the following NHSMs are not solid wastes when burned as a fuel in combustion units and is therefore proposing to list them as categorical non-wastes under 40 CFR in section 241.4(a):

  • Creosote-borate and mixtures of creosote, copper naphthenate and copper naphthenate-borate 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 part 63 Subpart DDDDD that had been designed to burn biomass and fuel oil, but are modified (e.g., oil delivery mechanisms were 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. 
  • Copper naphthenate treated railroad ties combusted in units designed to burn biomass or biomass and fuel oil. 
  • Copper naphthenate-borate ties combusted in units designed to burn biomass or biomass and fuel oil.

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Why is EPA proposing these additions to the list of categorical non-waste fuels in the NHSM regulations under 40 CFR section 241.4(a)?

In the February 7, 2013 NHSM final rule, EPA established 40 CFR section 241.4(a) which is a list of categorical non-waste fuels. In the 2013 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 future rulemakings. 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.

The materials addressed in the 2016 proposed categorical other treated railroad tie (OTRT) rule have been mentioned in previous NHSM rulemakings. The February 8, 2016 final NHSM rule noted that EPA had reviewed a letter from the Treated Wood Council asking that creosote-borate, copper naphthenate, and copper naphthenate-borate treated railroad ties be added as categorical non-waste fuels. EPA stated that these three types of treated railroad ties are candidates for categorical non-waste listings and expected to begin development of a proposed rule to amend 40 CFR section 241.4(a) to add those listings in the near future. This proposed rule is the result of that commitment.

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What is the approach proposed for railroad ties treated with creosote-borate and mixtures of creosote-borate and copper naphthenate that are combusted in units that are no longer designed to burn fuel oil and have switched to natural gas?

Similar to the February 8, 2016 final rule on creosote treated railroad ties, the Agency is proposing an approach for railroad ties treated with creosote-borate and mixtures of creosote, borate and copper naphthenate that are combusted in units that are no longer designed to burn fuel oil and have switched to natural gas. Specifically, the Agency has sufficient information to propose to list as a categorical non-waste such treated railroad ties that are 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 ties will be able to be combusted as product fuel only if certain conditions are met, which are intended to ensure that they are not being discarded:

  • The railroad ties treated with creosote-borate and mixtures of creosote, borate and copper naphthenate 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
  • Such ties can comprise no more than 40 percent of the fuel that is used on an annual heat input basis.

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In general, what is the purpose of the NHSM rules?

The NHSM rules establish 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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How does the 2016 NHSM proposed rule impact the regulated community?

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 proposed 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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