On March 21, 2011, the U.S. EPA promulgated a new regulation known as the Identification of Non-Hazardous Secondary Materials That are Solid Waste When Used as Fuels or Ingredients in Combustion (NHSM Regulation), codified under 40 CFR Part 241 Subpart B. In short, the NHSM regulation is used to determine whether secondary materials are considered "solid wastes" (which are subject to the more stringent CISWI Incinerator Standards), or are "legitimate fuels" when combusted. "Secondary materials" are basically materials generated from manufacturing processes that are not the primary product(s) of that process. Candidate solid wastes can include gaseous materials (e.g., landfill gas, biogas from digestion, and other gasified materials), liquid materials (e.g., wastewater and associated sludges) or solid materials (e.g., process rejects or unused raw materials). Currently, the only categorically exempt material is "clean cellulosic biomass."

The NC DAQ has been rigorously enforcing the NHSM regulations for construction (and modification) applications involving combustion of potential solid wastes. In general, the NC DAQ has not begun processing of permit applications involving combustion of potential solid wastes until a determination of whether the material being combusted is a solid waste or not. Due to complexity of making such determinations, most projects have encountered delays of several months or more, as they work through the process with the DAQ. It should be noted that under the current NHSM and CISWI rules, the NC DAQ will also begin requiring solid waste determinations for existing, unmodified combustion sources as future CISWI compliance deadlines approach.

In short, the NC DAQ's approach aligns with federal regulations that assesses whether NHSMs are "solid wastes" when combusted using a "legitimacy test," which establishes whether or not the material is a "legitimate" fuel. NHSMs are considered legitimate fuels if they meet the following criteria:

  1. The NHSM must be managed as a valuable commodity 
  2. The NHSM must have a meaningful heating value and be used as a fuel in a combustion unit that recovers energy. 
  3. The NHSM must contain contaminants at levels comparable in concentration to or lower than those in traditional fuels which the combustion unit is designed to burn. 

Trinity has already has extensive experience with the NHSM regulations, including DAQ-specific implementation policy.