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January 10, 2013

EPA Issues Long-Awaited Final Rule Revising Standards for Commercial and Industrial Solid Waste Incineration Units and Revising the Definition of Nonhazardous Secondary Materials

The ACTA Group

On December 20, 2012, U.S. Environmental Protection Agency (EPA) Administrator Jackson signed a much-anticipated rulemaking package revising the emission standards for commercial and industrial solid waste incineration units (CISWI). The rule has not yet been published in the Federal Register. The final rule accomplishes two broad goals: it revises the Clean Air Act (CAA) emission limits for CISWIs, and it revises the definition under the Resource Conservation and Recovery Act (RCRA) of “nonhazardous secondary material” (NHSM). More information regarding the adjustments for major and area source boilers and CISWIs is available online. More information regarding the NHSM amendments is available online.

As to the CAA portion of the rule, EPA revised certain of the emission limits under the CAA for CISWIs and other requirements for these units. The RCRA portion of the rule attempts to define clearly what nonhazardous wastes would be considered solid wastes when burned. The two portions of the rule work in tandem: when burned, NHSMs that meet the definition of solid waste must be incinerated in CISWIs, while NHSMs that do not meet the definition of solid waste could be burned as fuels in boilers (which are subject to less stringent standards under CAA).


The rule has been over a decade in the making. EPA first promulgated standards for CISWIs in December 2000. After a torturous eleven-year path of litigation and rulemaking, EPA in March 2011 promulgated final revisions to the CISWI standards. The March 2011 rule sparked a firestorm of opposition from stakeholders. EPA received over 50 petitions for reconsideration from industry, states, and environmental groups. Based on these petitions and EPA’s admission the March 2011 rule may have missed the mark, in May 2011 EPA postponed the effective dates of the March 2011 rule. Then in December 2011, EPA issued proposed revisions to the standards, which it believed reflected the additional comments and data it had received from stakeholders. The December 20, 2012, rule is EPA’s attempt to issue these revised standards in final.

The controversy surrounding this rule is due in large part to its broad scope and estimated costs of compliance. EPA estimates that there are more than 1.5 million boilers and 106 CISWI units in the United States. EPA estimated that its March 2011 rule would impose annual costs of approximately $300 million. Many industry stakeholders believed the rule would cost twice as much, if not more, and that the March 2011 standards would be virtually impossible to achieve.

Revisions to CISWI CAA Requirements

The scope of the revisions continues to be broad. EPA defines a CISWI as:

[A]ny distinct operating unit of any commercial or industrial facility that combusts, or has combusted in the preceding 6 months, any solid waste as that term is defined in 40 CFR part 241. If the operating unit burns materials other than traditional fuels as defined in §241.2 that have been discarded, and you do not keep and produce records as required by [40 C.F.R.] §60.2175(v), the operating unit is a CISWI unit. While not all CISWI units will include all of the following components, a CISWI unit includes, but is not limited to, the solid waste feed system, grate system, flue gas system, waste heat recovery equipment, if any, and bottom ash system. The CISWI unit does not include air pollution control equipment or the stack. The CISWI unit boundary starts at the solid waste hopper (if applicable) and extends through two areas: The combustion unit flue gas system, which ends immediately after the last combustion chamber or after the waste heat recovery equipment, if any; and the combustion unit bottom ash system, which ends at the truck loading station or similar equipment that transfers the ash to final disposal. The CISWI unit includes all ash handling systems connected to the bottom ash handling system.

EPA believes, however, that the revisions will ease the compliance burdens for owners and operators of CISWIs while continuing to improve protection of human health and the environment from emissions from these units. EPA estimates that the standards will avoid up to 8,100 premature deaths, 5,100 heart attacks, and 52,000 asthma attacks. EPA further estimates that Americans will receive $13 to $29 in health benefits for every dollar spent to meet the final standards.

EPA appears to have narrowed the scope of the rule and to have issued standards that likely will be more amenable to affected industries. EPA states that the standards will not apply to 86 percent of all boilers, because these boilers burn clean natural gas at area source facilities and emit little toxic air pollution. For almost 13 percent of all boilers, the standards will continue to rely on practical, cost-effective work practice standards to reduce emissions, EPA said. For the highest emitting 0.4 percent of all boilers (which likely will include those units located at refineries, chemical plants, and other industrial facilities), EPA issued what it believes to be more focused, revised numeric emission limits that provide industry practical, cost-effective options to meet the new standards. EPA also extended the compliance deadlines in the final rule. Owners or operators of existing major source boilers will have until 2016 to come into compliance with the standards, while owners or operators of area source boilers subject to the rule must meet the new standards by March 21, 2014. Existing CISWIs have until 2018 to meet the revised standards.

The final rule eases the emission limits for several key pollutants. The following table summarizes EPA’s revisions to the standards for specific pollutants.

Toxic PollutantsEmission Reductions from All Rules Combined
(tons per year)
March 2011 Final RuleDecember 2012 Final Rule
Mercury1.62.0 – 3.0
Non-mercury metals3,0002,100
Hydrogen Chloride30,50040,500
Particulate Matter (PM2.5)30,00018,000
Sulfur Dioxide450,000580,000

Standards for Major Source Boilers

EPA calculates that there are approximately 14,000 major source boilers and process heaters in the U.S. Eighty-eight percent of those burn clean fuels and will be required to conduct periodic tune-ups under the final rule. Twelve percent will be required to take steps to meet numeric emission standards if they do not already meet the standards. Based on additional data provided after EPA issued the March 2011 rule, EPA is adjusting the standards by:

  • Creating new subcategories for light and heavy industrial liquids to reflect design differences in the boilers that burn these fuels. EPA states that this change will improve the standards’ achievability without decreasing public health protections.
  • Creating a new subcategory for coal fluidized bed units with a fluidized bed heat exchanger designed to burn coal. This change results in a more targeted, achievable standard, EPA states.
  • Setting new emission limits for particulate matter for each biomass subcategory to better reflect emissions during real-world operating conditions.
  • Setting new emission limits for carbon monoxide (CO) based on new data that show CO emissions from boilers vary greatly. EPA is setting new limits to capture that variability.
  • Allowing an alternative total selective metals emission limit to regulate metallic air toxics instead of using PM as a surrogate, allowing more flexibility and decreasing compliance costs for units that emit low levels of hazardous air pollutant (HAP) metals.
  • Replacing numeric dioxin emission limits with work practice standards because EPA believes dioxin emissions are below levels that can be accurately measured.
  • Increasing flexibility in compliance monitoring by adding alternative monitoring approaches for demonstrating continuous compliance with the PM limit.

Standards for Area Source Boilers

EPA believes area source boilers do not emit pollutants in concentrations or quantities sufficient to warrant substantive regulation. The final rule thus allows the majority of owners or operators of area source boilers subject to the rule to employ work practices and management standards in lieu of numerical emission limits. EPA estimates that less than one percent of area source boilers will need to meet numerical emission limits. Nonetheless, EPA adjusted the limits for this one percent. It believes the adjustments will not increase the costs of the standards but will result in a decrease in burden on small facilities. Among other things, EPA established subcategories for seasonal use boilers and limited use boilers that it believes will reduce the compliance burden for these less frequently used boilers. EPA also revised provisions for existing dual-fuel fired units that fuel switch from gas to coal, biomass or oil such that they would still be considered existing sources, promoting flexibility for these existing sources that were designed to accommodate an alternate fuel.

Revisions to NHSM Regulations

The RCRA portion of this massive rule attempts to define more clearly what nonhazardous wastes would be considered solid wastes when burned. This is an important distinction. When burned, NHSMs that meet the definition of solid waste would have to be burned in CISWIs that are subject to stringent regulation under CAA Section 129. NHSMs that do not meet the definition of solid waste could be burned as fuels in boilers, which are subject to less stringent standards under CAA Section 112.

In the final rule, EPA revised the standards at 40 C.F.R. Part 241, which identifies those NHSMs that are considered solid wastes when used as fuels or ingredients in CISWIs. NHSMs — defined as a secondary material that, when discarded, would not be considered a RCRA hazardous waste — that are combusted are generally considered solid waste (and thus must be burned in CISWIs), unless an EPA Regional Administrator grants a non-waste determination petition.

Despite all of the controversy surrounding this portion of the rule, EPA made slight revisions, and the bulk of those address so-called “legitimacy criteria.” Under the final rule, several categories of NHSMs are not considered solid waste when combusted. These are:

  • NHSMs that are used as a fuel in a combustion unit and that remain with the control of the generator and that meet specified legitimacy criteria.
  • NHSMs used as an ingredient in a combustion unit and that meet specified legitimacy criteria.
  • Fuel or ingredient products that are used in a combustion unit and that are produced from the processing of discarded NHSMs.
  • Scrap tires that are not discarded and that are managed under the oversight of established tire collection programs.
  • Resinated wood.
  • Coal refuse that has been recovered from legacy piles and processed in the same manner as currently generated coal refuse.
  • Dewatered pulp and paper sludges that are not discarded and are generated and burned on-site by pulp and paper mills that burn a significant portion of such materials where such dewatered residuals are managed in a manner that preserves the meaningful heating value of the materials.

EPA also revised the definition of NHSM to ensure that materials that are traditional fuels are not considered solid waste. One of the more significant changes it made in the rule is to revise the definition of “clean cellulosic biomass.” EPA provides a list of clean cellulosic biomass materials that qualify as a traditional fuel (and not solid waste), described as materials that have not been altered, such that they contain contaminants at concentrations normally associated with virgin biomass materials. Specifically, the definition now reads as follows:

Clean cellulosic biomass means those residuals that are akin to traditional cellulosic biomass, including, but not limited to: agricultural and forest-derived biomass (e.g., green wood, forest thinnings, clean and unadulterated bark, sawdust, trim, tree harvesting residuals from logging and sawmill materials, hogged fuel, wood pellets, untreated wood pallets); urban wood (e.g., tree trimmings, stumps, and related forest-derived biomass from urban settings); corn stover and other biomass crops used specifically for the production of cellulosic biofuels (e.g., energy cane, other fast growing grasses, byproducts of ethanol natural fermentation processes); bagasse and other crop residues (e.g., peanut shells, vines, orchard trees, hulls, seeds, spent grains, cotton byproducts, corn and peanut production residues, rice milling and grain elevator operation residues); wood collected from forest fire clearance activities, trees and clean wood found in disaster debris, clean biomass from land clearing operations, and clean construction and demolition wood. These fuels are not secondary materials or solid wastes unless discarded. Clean biomass is biomass that does not contain contaminants at concentrations not normally associated with virgin biomass materials.