Recycling or
Disposal?
Hazardous Waste Combustion in Cement Kilns
VII. Conclusion
Most of the hazardous waste being burned in the United States today is combusted in boilers and industrial furnaces - primarily cement kilns - which were not originally designed for the job. At this writing, none of these kilns has obtained a federal hazardous waste disposal Part B permit. Federal environmental standards emphasizing risk-based controls and less than state-of-the-art technology standards for these "interim status" facilities are significantly less stringent than the performance levels being achieved in practice under both state and federal regulation at federally RCRA-licensed waste incineration facilities, particularly with regard to disposal of process residues including kiln dust as compared to waste incinerator process residues. Compliance with interim standards under the BIF rules depends almost entirely on self-certification by the facilities rather than mandatory reporting and EPA testing, inspection, and verification.
Except for particulate emissions control standards, existing BIF regulations are mostly risk-based standards. Risk assessment methodologies are based on assumptions about emissions rates, dispersion, dose-response factors, and exposure pathways. Some of these assumptions can fairly be described as highly speculative. Risk analysis also ignores other relevant factors, such as synergistic and cumulative effects, and non-human health impacts. Often, too little is known to do more than educated guess-work in evaluating potential health risks from emissions.
In practical terms, the risk-based approach can discourage innovation by ratifying existing technology and operational practices which are determined to be "safe." Indeed, it has even been suggested that the final BIF rules were crafted to allow cement kilns to continue burning hazardous waste using their current equipment and practices.
EPA is currently reviewing its administrative rules for hazardous waste combustors. The Agency has made a preliminary decision to require technology-based emissions standards for all hazardous waste combustors, including BIFs.
Although EPA has decided to regulate cement kiln dust using hazardous waste authority, many details in exactly how this will be done and the form of the final regulations remain to be set. Pending final revision of the rules, EPA has urged its regional offices to apply more stringent standards than the BIF rules require on a case by case basis, using the Agency's omnibus permitting authority under RCRA Sec. 3005. In addition, there will be an important role for citizens to play in the interim to seek both state and federal controls on serious fugitive dust emissions that frequently occur from CKD disposal sites.
This is a time of extraordinary opportunity for environmental activists, community organizations, and concerned citizens. EPA regional offices are processing more hazardous waste permit applications, with more freedom to exercise discretion in imposing requirements. Citizens have more ability to influence the permitting process by advocating innovative, strict environmental controls. Successful local innovations can serve as precedent for national policy reforms.
On the national level, EPA is still formulating its waste minimization and combustion policies. Opportunities for citizen input into this process are still frequent and relatively informal. The Agency's new awareness of environmental justice issues also broadens the opportunity for citizen input.
From an environmental standpoint, the effort to revise requirements for hazardous waste combustors should focus on two critical issues. The first issue is whether the revised regulations should require uniform standards for all hazardous waste combustors or different standards based on facility type.
From an environmental perspective, uniform waste combustor standards represent the sounder approach. It does not make sense to regulate the treatment, storage or disposal of hazardous waste material on the basis of origin rather than characteristics. Uniform standards based on a MACT analysis of the best-performing hazardous waste combustion units - irrespective of facility type - would provide greater protection to human health and the environment than separate standards because all combustors would have to perform as well as the best-performing twelve percent of all units regardless of type (i.e., the "best of the best.") Such standards, particularly for metals emissions, would also lower the overall amount of metals emitted as a result of hazardous waste combustion activities. Finally, from an environmental justice standpoint, it seems fundamentally unfair expose some local populations to greater emissions merely because they live near a particular type of facility.
From an economic perspective, there is little logic in imposing discriminatory regulations on competitors in the same marketplace. Governmental regulations that do not afford even-handed treatment to competitors hinder competition, eventually leading to higher costs and slowing the pace of technological innovation. Interim standards for BIFs and the "Bevill exemption" for cement kiln dust and other BIF process residues give the hazardous waste-burning cement kiln industry major advantages over the commercial incinerators in the hazardous waste marketplace. Since there is no shortage of hazardous waste combustion capacity in the U.S. there do not appear to be any clear countervailing benefits for these regulatory advantages. Certainly, the argument that standards for BIFs should be looser to enable BIFs to "help solve the hazardous waste disposal problem" seems to be something less than compelling.
The second major concern is to redefine and clarify the recycling exemptions to RCRA to assure that net environmental benefits are derived from so-called recycling activities. It is not clear that the various regulatory exemptions for "recycling" activities in current federal hazardous waste law and regulations actually encourage genuine recycling. It is certainly legitimate to ask, for example, whether using the BTU value of waste to produce cement can even be considered recycling, particularly when such burning eclipses solvent and oil recycling operations.
Proponents of the use of hazardous waste fuel argue that kilns recycle the energy value of waste whereas incinerators do not. However, both hazardous waste burning kilns and incinerators use the BTU value of waste to perform tasks society deems important; producing cement in one case; detoxifying dangerous chemicals on the other. Moreover, neither activity constitutes "closed-loop" recycling, in that a portion of the hazardous constituents of the waste ends up in the atmosphere or in process residues. In the case of cement kilns, significant amounts of hazardous metals also end up in cement product. Even higher metal levels may occur in the future. If CKD is regulated as a hazardous waste, kiln operators can be expected to recycle more CKD in an effort to avoid disposal costs. A portion of the metals found in the recycled CKD will inevitably wind up in the cement product.
Policy-makers should strongly consider whether hazardous waste recycling activities should be narrowly defined to include only closed loop recycling. Certainly, at a minimum, hazardous waste processors claiming regulatory advantages as "recyclers" ought to be required to show a net energy benefit from using hazardous waste fuel as a substitute for conventional fuels. Fuel blending operations should be required to obtain hazardous waste treatment permits under RCRA. Among other things, this would require fuel blenders to comply with RCRA land disposal standards for hazardous waste fuel. Revised regulations should also prohibit fuel blending activities which permit kilns to burn non-combustible low-BTU value waste mixed with legitimate fuel unless kilns are subjected to stringent uniform regulatory requirements applicable to all hazardous waste combustors. Hazardous waste sent to fuel blenders or BIFs should also be included in Toxics Release Inventory Reports required by the Emergency Planning and Community Right to Know Act of 1986.
If kilns are permitted to continue burning hazardous waste, the issue of whether the use of hazardous waste affects cement quality and the issue of whether cement produced with hazardous waste poses unacceptable environmental risks warrant careful study. Congress should establish a deadline for submission of an EPA study on these issues. Kilns should not be permitted to continue burning hazardous waste if EPA fails to meet the deadline. Congress should also require that cement and aggregate products produced with hazardous waste to be labeled as such. It should be pointed out that state and local governments have the authority to regulate in these areas to impose more stringent standards and requirements than federal law, so long as the state or local measures do not conflict with federal law.
Upgrading environmental requirements for BIFs, including state-of-the-art emissions controls and strict disposal requirements for residues, especially CKD, would encourage waste minimization efforts by significantly increasing the costs of hazardous waste combustion. Our environment and our economy would benefit. Industry would become more efficient, fewer resources would be consumed in production processes and less investment in waste disposal would be required. The ultimate answer to our hazardous waste disposal problem lies in not generating as much waste to begin with in our industrial and consumer economy.
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