4 The record articles

Dazed and Confused: Alternative Fuels and the CISWI Definitions Rule

Posted: January 19th, 2012

Author: All4 Staff 


As discussed in ALL4’s December 2008 issue of 4 The Record, the use of alternative and non-traditional fuels for heat and power generation is on the rise, an increase that can be attributed to the price surge and volatility of traditional fossil fuels, as well as to a general desire to use more environmentally friendly materials to reduce greenhouse gas emissions. Alternative fuels have been successfully permitted and are being effectively used on a consistent basis as fossil fuel substitutes at numerous public, commercial, and industrial manufacturing facilities.  However, a Court decision in June 2007 initiated a series of events that will likley impact how facilities that utilize alternative or non-traditional fuels are regulated under the Clean Air Act (CAA). Any facility that currently burns non-hazardous alternative or non-traditional fuel, or is considering the introduction and use of a non-hazardous alternative fuel in an on-site combustion device, will benefit from an understanding of the history, approach, and air quality implications of current U.S. EPA regulatory developments.  Non-hazardous alternative or non-traditional fuels include, but are not limited to: biomass, construction and demolition material, scrap tires, scrap plastics, spent solvents, coal refuse, waste water treatment sludge, or used oil.


On December 1, 2000, U.S. EPA issued the Commercial and Industrial Solid Waste Incineration Rule (CISWI Rule), which established emission standards for CISWI units pursuant to Section 129 of the Clean Air Act (CAA).  In response to petitions filed by several environmental groups, U.S. EPA granted a motion for reconsideration and filed a motion for voluntary remand, which was issued on September 6, 2001.

On February 17, 2004, U.S. EPA solicited comments on several key definitions in the CISWI Rule including “solid waste,” “commercial or industrial waste,” and “CISWI unit.”  U.S. EPA then issued the CISWI Definitions Rule on September 22, 2005 after review and consideration of the public comments received.

In the September 22, 2005 CISWI Definitions Rule, a “CISWI unit” was defined as “any combustion unit that combusts commercial or industrial waste (as defined in this subpart).”  The CISWI Definitions Rule further defined “commercial or  industrial waste” as “solid waste (as defined in this subpart) that is combusted at any commercial or industrial facility using controlled flame combustion in an enclosed, distinct operating unit: whose design does not provide for energy recovery (as defined in this subpart); or is operated without energy recovery (as defined in this subpart).”  This definition captured only waste that was combusted at facilities that did not recover thermal energy for a useful purpose from the combustion of the material and therefore restricted the applicability of the CISWI Rule.  For example, boilers, process heaters, kilns, and other units burning those types of materials that used the energy from combustion were not CISWI units.

A petition for review of the CISWI Definitions Rule was filed by environmental groups on November 21, 2005. On June 8, 2007, the United States Court of Appeals for the district of Columbia Circuit (Court) agreed with the petitioners and both remanded and vacated the CISWI Definitions Rule.  The Court ruled that the definition of “commercial or industrial waste” in the CISWI Rule was in conflict with the statutory language of Section 129 since Section 129 applies specifically to “solid waste incineration units combusting commercial or industrial waste.”  Section 129 defines “solid waste incineration unit” to include “a distinct operating unit of any facility which combusts any solid waste material from commercial or industrial establishments or the general public (including single and multiple residences, hotels, and motels).”  In short, the Court determined that:

  • The Section 129 standards apply to any facility that combusts any commercial or industrial solid waste material, excluding available statutory exemptions.1
  • U.S. EPA incorrectly excluded units that combust solid waste for the purposes of energy recovery from the CISWI Definitions Rule.

The Court also determined that U.S. EPA incorrectly included units that combust commercial or industrial solid waste material in 40 CFR Part 63, Subpart DDDDD – National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers and Process Heaters (Boilers Rule), commonly referred to as Boiler Maximum Achievable Control Technology (MACT).  The Boilers Rule was promulgated in accordance with 112(d) of the CAA and was vacated and remanded at the same time as the CISWI Definitions Rule.  Since boilers by design recover thermal energy for a useful purpose, boilers combusting solid waste materials were excluded from applicability to the Section 129 regulations.  The Court’s decision to vacate and remand the Boilers Rule was based on the likelihood that the Boilers Rule would change substantially as a result of the vacatur of the CISWI Definitions Rule.  The Court’s rejection of U.S. EPA’s definition of “commercial or industrial waste” in the CISWI Definitions Rule would impact the applicability of both rules (CISWI and Boilers Rule) and result in an increase in units subject to the Section 129 rule and a matching decrease in units subject to the Section 112 rule (i.e., the Boilers Rule).   The Court’s decision will ultimately impact many facilities that are legitimately using non-hazardous or alternative fuels to supplement or replace the use of traditional fossil fuels.

U.S. EPA’s Approach

In U.S. EPA’s view, the key issue in responding to the Court’s decision was to establish what non-hazardous secondary2 materials constitute ‘‘solid waste’’ under the Resource Conservation and Recovery Act (RCRA).  The CAA states that the term solid waste shall have the same meaning as established under RCRA.  U.S. EPA currently believes that if a non-hazardous material is not a ‘‘solid waste’’ under RCRA and the material is burned for fuel value, then, under the Court’s decision, the combustion source should not be regulated under Section 129 of the CAA.

On January 2, 2009, U.S. EPA published an advance notice of proposed rulemaking (ANPR) seeking public comment and providing advanced notice of its intent to develop a definition for the term ‘‘solid waste’’ under RCRA for non-hazardous secondary materials that are used as a fuel or as ingredients in a manufacturing process.3 The stated purpose of the ANPR was to solicit input to assist U.S. EPA in developing emissions standards under Sections 112 and 129 of the CAA. The CAA defers to the meaning of “solid waste” under RCRA to define solid waste under the CAA. Note: U.S. EPA is considering revising the Definition of Solid Waste Rule, which excludes certain hazardous secondary materials that are being recycled under Subtitle C of RCRA (see our August 2009 4 The Record Guest Article for more information).

As explained in the ANPR, U.S. EPA is evaluating how many popular secondary materials are being used (e.g., as fuels or ingredients) and whether these materials should or should not be characterized as solid wastes under RCRA.4  U.S. EPA has identified eight (8) non-hazardous secondary material fuel groups in the ANPR.  U.S. EPA generally considers secondary materials to be a legitimate fuel if they are handled as valuable commodities (i.e., managed, at a minimum, in a manner consistent with the management of the analogous raw material), have meaningful heating value, and contain contaminants that are not significantly higher in concentration than traditional fuel products. Secondary materials meeting the above criteria would, in theory, not be considered solid waste under RCRA Subtitle D, and would not be subject to Section 129 requirements.  U.S. EPA has also identified (6) non-hazardous secondary material groups for further evaluation.  These secondary materials would be considered a legitimate ingredient in a manufacturing process if the secondary material is handled as a valuable commodity, the secondary material provides a useful contribution to the process or product, the recycling results in a valuable product, and the product does not contain contaminants that are significantly higher in concentration than traditional products.  Secondary fuel materials meeting the above criteria would, in theory, not be considered solid waste under RCRA Subtitle D, and would not be subject to Section 129 requirements.

U.S. EPA has not historically promulgated regulations that define solid waste for the RCRA Subtitle D (non-hazardous) waste programs. Rather, many states have promulgated regulations defining solid waste and have interpreted their regulations to determine what types of secondary materials management activities constitute “discarded” material (and therefore involve the management of a solid waste). U.S. EPA appears to be leaning towards specifically defining what non-hazardous secondary materials constitute solid wastes under RCRA Subtitle D.  In comments provided in response to the ANPR, the Association of State and Territorial Solid Waste Management Officials (ASTSWMO) has expressed concern to U.S. EPA regarding their proposed approach to defining non-hazardous solid wastes under RCRA Subtitle D. Their specific concerns relate to overlap with existing, well-defined state programs, stringency issues, and states’ flexibility in meeting their own solid waste management goals. Several state regulatory agencies have provided similar comments in response to the ANPR.

Air Quality Regulatory Implications

The air quality regulatory implications facing facilities that will be affected by these proceedings could be substantial.  Many facilities that operate sources using alternative or non-traditional fuels (e.g., cement kilns) are currently subject to standards developed under Section 112 of the CAA.5 Such facilities that currently use an alternative or non-traditional fuel that would meet a new definition of solid waste developed by U.S. EPA under RCRA Subtitle D could be subject to regulation under Section 129 of the CAA as a CISWI unit.6  For example, if an existing facility that is subject to a CAA Section 112 standard (e.g., a cement kiln) is utilizing an alternative fuel that is ultimately determined to be a RCRA Subtitle D solid waste, then that unit would become subject to an applicable Section 129 standard (i.e., the CISWI Rule). Standards developed under both Section 112 and Section 129 are based on Maximum Achievable Control Technology (MACT), but that is where the similarities end.  The major differences between Section 112 and Section 129 standards are outlined below:

  • Section 129 MACT standards apply to all sources within the defined category, regardless of their status as a major or minor source. Section 112 requires that MACT standards be established for major sources of hazardous air pollutants (HAPs) and certain area sources of HAPs.
  • Section 129 requires that emission standards minimally be set for nine (9) pollutants: cadmium, carbon monoxide, dioxins/furans, hydrogen chloride, lead, mercury, nitrogen oxides, particulate matter (total and fine), opacity, and sulfur dioxide. Section 112 Standards generally regulate a specific HAP of concern or regulate surrogate pollutants representing a category of HAPs (e.g., VOCs as a surrogate for volatile HAPs).
  • Section 129 includes requirements for operator training, pre-construction site assessments, and monitoring that are not included in CAA Section 112. Many standards developed under Section 112 do not include such requirements.
  • Section 129 applicability can be triggered by a modification as defined in 40 CFR Part 60, Subpart A.  Currently, Section 112 standards are not triggered by modifications.

What You Can Do

Any facility that currently burns non-hazardous alternative or non-traditional fuel or is considering the introduction and use of a non-hazardous alternative fuel, including but not limited to: biomass, construction and demolition material, scrap tires, scrap plastics, spent solvents, coal refuse, waste water treatment sludge, or used oil in an on-site combustion device will benefit from an understanding of the history, approach and air quality implications of current U.S. EPA regulatory developments. You can take the following steps to learn more about the regulatory process and the potential impacts to your operations:

  • Follow the regulatory development process very closely.  Regular visits to the online docket at www.regulations.gov [Docket No. EPA-HQ-RCRA-2008-0329] are recommended.
  • Become involved with the trade association that represents your particular industry (e.g., PCA, NCASI, AF&PA, CIBO, etc.).  Trade associations can be an effective means to track regulatory status and to provide comments.
  • Be aware of possible regulatory impacts on open plans and pending or planned projects.
  • Watch for updates in future editions of 4 The Record.

Final Thoughts

As with any major regulatory revision, there are significant risks to affected facilities. However, U.S. EPA has an opportunity to provide clarity and consistency regarding the use of legitimate alternative fuels.  Under the current system, the use of non-hazardous alternative fuels is often dictated by individual state regulations, programs, and policies.  Such regulations, programs, and policies differ substantially from state to state and even from differing management regions within state regulatory agencies.  In many instances, this lack of consistency and clarity results in confusion, misunderstanding, public opposition, permitting delays, and eventually unrealistic permit conditions.   Your input into the process could contribute to a reasonable outcome.


1 The term “solid waste incineration unit” does not include

(A) materials recovery facilities (including primary or secondary smelters) which combust waste for the primary purpose of recovering metals,

(B) qualifying small power production facilities, as defined in section 796 (17)(C) of title 16, or qualifying cogeneration facilities, as defined in section 796 (18)(C) of title 16, which burn homogeneous waste (such as units which burn tires or used oil, but not including refuse-derived fuel) for the production of electric energy or in the case of qualifying cogeneration facilities which burn homogeneous waste for the production of electric energy and steam or forms of useful energy (such as heat) which are used for industrial, commercial, heating or cooling purposes, or

(C) air curtain incinerators provided that such incinerators only burn wood wastes, yard wastes and clean lumber and that such air curtain incinerators comply with opacity limitations to be established by the Administrator by rule.

2 In the January 9, 2009 ANPR, U.S. EPA describes a secondary material as any material that is not the primary product of a manufacturing or commercial process, and can include postconsumer material, post-industrial material, and scrap.

3 While the focus of this article is primarily on the combustion of secondary materials, U.S. EPA also addressed non-hazardous secondary materials that are used as ingredients in manufacturing processes in the January 2, 2009 ANPR.

4 Under the court’s decision, any unit combusting any ‘‘solid waste’’ at all must be regulated as a ‘‘solid waste incineration unit,’’ regardless of the function of the combustion device.

5 Most industrial, commercial, and institutional boilers and process heaters, including those using alternative fuels, were subject to the Boilers Rule prior to its vacatur. Most cement kilns, including those using non-hazardous alternative fuels, are subject to 40 CFR Part 63, Subpart LLL (promulgated in accordance with Subpart 112 of the CAA).

6 Section 129 (h)(2) of the CAA specifies that solid waste incineration units that are subject to Section 129 standards shall not be subject to standards developed under Section 112.


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