The EPA is seeking to add three categories of materials to its list of nonhazardous secondary materials (NHSMs) that are not wastes when burned in combustion units.

The impact of the proposal can be significant for units that currently combust these materials.  First, it frees operators of the burden of making an individual demonstration that the materials satisfy EPA’s legitimacy criteria and therefore qualify as an NHSM.  Second, for operators who have not made the requisite demonstration, the proposal would exempt them from complying with the emissions standards for incinerators under Clean Air Act (CAA) Section 129 provided they do not combust other nonlisted wastes.  Instead, the somewhat less onerous requirements under CAA Section 112 for commercial, industrial, and institutional boilers would apply.  This would be a federal provision that states can adopt or not adopt at their discretion.

Proposed materials

The EPA is proposing to define the following materials as NHSMs when combusted and provided conditions attached to each material are met:

• Construction and demolition (C&D) wood processed from C&D debris according to best management practices
• Paper recycling residuals, including old corrugated cardboard rejects, generated from the recycling of recovered paper and paperboard products and burned on-site by paper recycling mills, the boilers of which are designed to burn solid fuel
• Creosote-treated railroad ties (CTRTs) that are processed and combusted in units designed to burn both biomass and fuel oil

C&D BMPs

The main conditions apply to C&D wood.  Combustors of C&D wood must obtain a written certification from C&D processing facilities that the C&D wood has been processed by trained operators in accordance with best management practices (BMPs).  For the purposes of the listing, BMPs must include sorting by trained operators, which excludes or removes specified materials from the final product fuel. These materials include nonwood 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.

In addition, C&D processing facilities that use positive sorting—where operators pick out desirable wood from commingled debris—must either exclude all painted wood 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.

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

Cost savings

While the EPA did not perform a detailed economic analysis, the Agency estimates that operators who combust CTRTs and no other solid waste may realize savings of $266,000 annually because of the potential modification and operational adjustments of their affected units.  In addition, the EPA says the improved regulatory clarity and certainty that would result from finalizing the proposal may stimulate increased product fuel use for one or more of the NHSMs, potentially resulting in upstream life cycle benefits associated with reduced extraction of virgin materials.

The proposal is the second listing of materials that are NHSMs when combusted and provided certain conditions are satisfied.  The first action, which was part of the Agency’s February 2013 NHSM rule, listed scrap tires, resinated wood, coal refuse, and dewatered pulp and paper sludges.  As with the current proposal, to qualify as an NHSM, certain conditions would apply to each of these materials.  For example, coal refuse must be recovered from legacy piles and processed in the same manner as currently generated coal refuse. 

The proposal was published in the April 14, 2014, FR.