As an initial matter, KRC assumes that the most recent of the three filings (May 2006) is the application that reflects accurately the waste stream that is proposed to be treated on-site in the open burn unit (off-spec gas generant pellets only) and the manner of initiating the burn (resistor wire and propane).
Earlier iterations of the RCRA Application identified two distinct burn areas – one for inflators and the other for pellets (February 2005) and proposed the use of kerosene to ignite the burn for one of the units and propane for the other (February 2005). Similarly, the December 2005 Application covered two RCRA treatment units to be co-located ion one pad – an inflator burning box and a pellet burn cage; and four waste streams proposed to be treated: gas generant pellets, off-spec assembled airbag inflators, initiators, and enhancer cups. The May 2006 Revised Application covered one RCRA-permitted open burn unit and only one waste stream – waste gas generant pellets. It is not immediately apparent from the revised application the manner in which the other waste streams are proposed to be managed, or the basis for concluding that those waste streams were not subject to Part B requirements. The Cabinet should inquire further about the proposed management of the other waste streams, and should strictly limit the waste stream authorized for treatment to that identified in the Revised Application.
After reviewing the initial Part A and B Permit Application (February 2005), the Part B Application filed in December, 2005, and the “Revised” Part B Application filed in May, 2006, KRC offers these comments and concerns regarding the tentative decision to issue the requested Part B permit authorizing the use of open burning as a treatment technology for the off-spec “gas generant pellets:”
1. The May 2006 Revised RCRA Application (hereinafter “the application”) does not provide sufficient characterization of the byproducts of the open burning of the gas generant pellets, nor of the resulting fly and bottom ash generated during the burn, over a range of operating scenarios.
The environmental performance standards of 40 CFR 264.601 (401 KAR 34:250 and 38:230) for miscellaneous units require that the unit be “located, designed, constructed, operated, maintained and closed in a manner that will ensure protection of human health and the environment.” The Division is given wide latitude to include as permit conditions “such terms and provisions as necessary to protect human health and the environment, including, but not limited to, as appropriate, design and operating requirements, detection and monitoring requirements, and requirements for responses to releases of hazardous waste or hazardous constituents from the unit.” 40 CFR 264.601; 401 KAR 34:250.
More specifically, the regulations instruct that protection of human health and the environment includes, with respect to air releases, prevention of any release “that may have adverse effects on human health or the environment due to migration of waste constituents in the air, considering: (1) . . . the physical and chemical characteristics of the waste in the unit, including its potential for the emission and dispersal of gases, aerosols and particulates; (2) The effectiveness and reliability of systems and structures to reduce or prevent emissions of hazardous constituents to the air; [and] (3) The operating characteristics of the unit[,]” among other factors.
Essential to the determination of whether the emissions from the open-air combustion of the gas generant pellets might pose such a threat, is the thorough characterization of the byproducts of combustion and of incomplete combustion, including sampling and analysis of the fly ash as well as bottom ash created in the combustion process, and a sampling profile of the gases generated at the edges of the burn process as well as at the center of the burn. Where, as here, the combustion process is not a controlled burn where the temperature and residence time of the combustion is adjusted to assure attainment of a high degree of efficiency in combustion and minimization of the creation of products of incomplete combustion, the composition of emissions of particulates, aerosols and gases may vary significantly.
KRC recommends that the applicant be required to provide the results of a complete TCLP metals and organics analysis of representative composited samples of the fly ash and bottom residue of treated pellets under all operating scenarios in order to determine whether the residue is non-hazardous.
The TCLP report included in Appendix F sampled from the center of the burn unit, where presumably combustion will be more complete than at the fringes of a burn that does not rely on auxiliary heat to assure a stable thermal profile across the waste treatment unit. Additionally, the sample was produced used kerosene rather than propane for ignition. Finally, the sampling was conducted roughly using a 50-50 mix of the two pellet types (50.78% QB / 49.22% NQ) and it is unclear whether that is the feed combination that will be combusted in all cases, or whether there may be instances in which the waste mix will vary. The characterization of the combustion emissions, fly and bottom ash residue must be provided under all operating scenarios, using representative burn agents, and providing results for both metals and organics, since the absence of a particular organic constituent in the raw material does not necessarily determine whether such a constituent can be created during open-air combustion.
2. The application lacks sufficient data concerning the composition of the gases and fly ash liberated during the combustion process to enable the agency to meet the requirements of 40 CFR 264.601. The application does not address the composition of any fine particulate matter generated in the combustion process. The application notes, but does not provide, analytical data showing that the pellets release only 2% TSP; a number that seems extremely low given the uncontrolled nature of the burn and the lack of controls on particulates in the unit.
The lack of characterization and discussion of the fate and transport of those particulates, including an analysis of any metals and organics that sorb to the fly ash and are emitted by the burn process, must be addressed by submittal of more complete data from a comparable unit under all operating scenarios.
3. The evaluation of alternative treatment approaches should be expanded to include other technologies that offer more control over the combustion conditions and resulting particulate, aerosol and gaseous emissions. The application notes only two alternatives considered – a chemical destruction system rejected as being experimental and generating corrosive waste, and an enclosed detonation chamber. EPA Region IV’s Information Resource Site identifies a number of potential alternative technologies, including the Donovan Blast Structure; the US Army Corps of Engineers Huntsville, Alabama Blast Containment Structure; Hurd Burn Units, and the U.S. Navy’s Confined Burn Facility, to name a few.
Thank you for your consideration of these comments.