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

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Why did EPA add categorical additions to the NHSM Rule?

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 OTRT final categorical rule have been mentioned in previous NHSM rulemakings.  The February 2016 final NHSM rule noted that EPA had reviewed Treated Wood Council (TWC) submissions asking that creosote-borate, copper naphthenate, and copper naphthenate-borate treated railroad ties be added as categorical non-waste fuels with supporting information and documentation. EPA stated that these three treated railroad ties were candidates for categorical non-waste listings and expected to begin development of a proposed rule under Title 40 of the Code of Federal Regulations (CFR) section 241.4(a) regarding those listings in the near future. After review of the data, EPA has concluded that these ties warrant a categorical listing.

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What materials are included in the OTRT final rule?

In this final rule, EPA is listing the following three materials as categorical non-wastes under 40 CFR section 241.4(a), thus defining them as non-wastes fuels when burned in combustion units:

  • 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; (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 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. Such units in (ii) must be existing stoker, bubbling bed, fluidized bed or hybrid suspension grate boilers where the OTRT comprise no more than 40 percent of the annual fuel load for that boiler. Also, units meeting (i) and (ii) can be designed to burn coal as well.
  • Copper naphthenate treated railroad ties combusted in units designed to burn biomass, biomass and fuel oil, or biomass and coal.
  • Copper naphthenate-borate ties combusted in units designed to burn biomass, biomass and fuel oil, or biomass and coal.

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What is the approach adopted 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 including an approach for railroad ties treated with creosote-borate and mixtures of creosote, borate and copper naphthenate units 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 list as a categorical non-waste such treated railroad ties 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. The ties can continue 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 OTRT NHSM final 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 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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Why is the rule immediately effective upon publication?

OTRTs represent a relatively small percentage of the railroad ties in use with the majority being creosote treated railroad ties (CTRTs). When the railroad ties are taken out of service and used as fuel, there is no way to distinguish between the OTRTs and the CTRTs. In order to ensure that CTRTs mixed with OTRTs are not considered a waste, EPA is making this final rule effective immediately and providing regulatory certainty.  

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