Hazardous waste control Are we creating problems for future generations? Every year approximately one ton of hazardous waste is added to the environment for each person in the U.S. Although there is some disagreement and uncertainty about the exact amount of hazardous waste produced annually, there is a general consensus that the quantity subject to federal regulation is in the range of 30 to 60 million tons. Hazardous waste exempted from federal regulation but covered by state regulations adds another 230-260 million tons, making the total number of tons comparable to the population of this country (see Table 1). Recently both the Office of Technology Assessment (OTA) and the National Academy of Sciences (NAS) published reports on the management of hazardous wastes. Although these reports do not have the same focus, there is a striking similarity in the opinions and ideas contained in them. (The NAS report is oriented toward the required control technologies, whereas the OTA report focuses somewhat more on changes in regulations that might improve hazardous waste control.) According to these reports, as much as 80% of the 260-320 million tons of hazardous waste produced annually is disposed of in or on the land. Many of the hazardous materials placed in landfills are highly toxic and remain hazardous for hundreds of years. The committee that prepared the NAS report decided that "at least 500 years is realistic as a period of concern for hazardous wastes in landfills...." Regulations under the Resource Conservation and Recovery Act (RCRA), however, require monitoring for only 30 years after a landfill is closed. Therefore, it could begin to leak toxic substances during the centuries following its shutdown, and the leak would not be detected by legally required monitoring. 0013-936X/83/0916-0281A$01.50/0
©
Also, there is a scientific consensus that no matter how well a landfill is designed, no matter what the liner and cap are made of, the landfill eventually will leak. As the OTA report states, "even with new stricter RCRA regulations in place, eventual releases of hazardous constituents from land disposal facilities are highly probable." The NAS publication also concludes that with time, the surface cover over a landfill can be penetrated and mobile constituents can leak to groundwater. Thus, both studies conclude that landfills appear to be an inexpensive method of waste disposal, but because they require monitoring and maintenance for hundreds of years, they transfer part of the cost of waste disposal to future generations. Eventually, 30 or 100 or 200 years laterwhenever the landfill begins to leak-more money will be spent to control hazardous releases and contain
1983 American Chemical Society
the wastes. These costs will be borne by government or by society in general instead of by the generator. The 30year postclosure monitoring requirement hides the true cost of long-term care. Besides the too-short postclosure monitoring requirement, the OTA and NAS reports say that existing regulations for landfills contain other deficiencies. Stringent monitoring is not required even while the landfill is in operation. The regulations require merely that four ambient groundwater samples be taken fOUf times a year. No air monitoring is required to determine if emissions of volatile organic compounds pose a health hazard. Retrofitting to meet new standards, such as the installation of a liner, is not required at existing active landfills, nor is it required for those portions of existing landfills that do not yet contain waste. No geological strategies for Environ. Sci. Technol., Vol. 17, No.7, 1983
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TABLE 1
Examples of hazardous wastes exempted from federal regulation Estimated annual generation (million metric tons)
Waste type
Fly and bottom ash from burning fossil fuels
66 Unknown
Fuels gas emission control waste Mining waste, including radioactive waste
2100
Domestic sewage discharged into publicly owned treatment works
5
Possible hazard
Determined by
Trace toxic metals
RCRA
Toxic organics and inorganics
RCRA
Toxic metals, acidity, radioactivity Uncertain, toxic metals likely
RCRA RCRA
Alkalinity, toxic metals
RCRA
Unknown
Alkalinity, toxic metals, toxic organics, salinity
RCRA
NPDES-permitted industrial discharge
Unknown
Toxic organics, heavy metals
RCRA
Irrigation return flo.ws
Unknown
Pesticides, fertilizers
RCRA
12
Cement kiln dust Gas and oil drilling muds and production waste; geothermal energy waste
19
Waste burned as fuels Waste oil
Unknown
Infectious waste
Unknown
2.7-4.0
Small-volume generators
Unburned toxic organics
EPA
Toxic organics, toxic metals
EPA
Infectious materials
EPA
Possibly any hazardous waste
EPA
Agricultural waste
Unknown
Variable
EPA
Waste exempted under delisting petitions a
Unknown
Presumably insignificant
EPA
Deferred regulations
Unknown
Unknown
EPA
EPA deregulation
Unknown
Presumably insignificant
EPA
Toxicity test exemptions b
Unknown
Organics
EPA
Recycled waste C
Unknown
Improper application of various materials
EPA
a Wastes may be delisted on the basis of a petition that concerns only the constituents that have determined the original listing; however, other hazardous
constituents may be present that have previously been unrecognized administratively. b Wastes not identified as toxic by the EPA extraction procedure test and not otherwise listed by EPA C Legitimate recycling is exempt from RCRA regulations except for storage. However, there have been numerous incidents, such as the dioxin case in Missouri, involving recycled materials that are still hazardous. Source: Adapted from "Technologies and Management Strategies for Hazardous Waste Control"; U.S. Congress, Office of Technology Assessment, Washington, D.C. 20510
protecting drinking water supplies are mandated in regulations for siting new landfills. Hidden costs Both NAS and OTA conclude that lax policies regarding landfills make them more economical than other alternatives and encourage industry to use them for nearly all its wastes. If industry had to pay the true cost of landfill disposal-the cost of containing the wastes over hundreds of years-it would be far more inclined to use other methods. Alternatives to land disposal could cost 50-100% more today than current disposal costs. But cleaning up newly created sites years from now might cost 10-100 times this additional outlay. NAS and OTA advocate minimal use of landfills and changes in regulations that will encourage the use of other methods of disposal. Current regulations, they say, provide disincentives for other disposal methods. Neither report states, however, that landfills can be eliminated entirely as a method of hazardous waste disposal. Both conclude that even with ideal 282A
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waste disposal treatment methods, some wastes would have to be disposed of on land. But they agree that the amount of waste placed in landfills can be reduced drastically. Hierarchy of options Rather than relying almost exclusivelyon land disposal, OTA and NAS propose that a hierarchy of options be used. "There are basically three general options," N AS writes, "Elimination [or reduction] or reuse of the hazardous waste, conversion of the hazardous waste into nonhazardous or less hazardous material, and perpetual storage." These options and general methods for achieving them are diagramed in Figure 1. Neither OTA nor NAS believes that there is a panacea for all hazardous wastes. But NAS considers the first general set of options, which it calls in-plant options, "probably the most economical and effective means of managing hazardous wastes." Included in this category are process modifications, such as altering the chemistry or certain other aspects of engineering operations, and recycling
and reuse of the hazardous by-products. For certain wastes, process modifications do not eliminate the wastes entirely but reduce their volume or degree of hazard. For example, modifications to the mercury electrolysis cell have resulted in reductions in the major types of waste produced by the chloralkali industry. For the wastes that are not eliminated by in-plant options, NAS advocatesthatth~secondsetofoptionsbe
used-conversion of the hazardous waste into nonhazardous or less hazardous material. The NAS committee members evaluated the state of development of the different methods in this category and pointed out research needs in each area. Although chemical and physical techniques could be used, in principle, to dispose of any hazardous waste, these methods would be too expensive for some wastes. The committee recommends that much additional research be performed in this area, such as: • continued experimental determination of various hazardous waste species and mixtures; • further development of processes
to remove metals from industrial waste streams; • further development of separation processes based on supercritical fluids, liquid membranes, and foam fractionation; and • development of a low-cost process to remove water from slimes and sludges. A large number of biological treatment processes exist that use indigenous or adapted microbes to remove or detoxify wastes. NAS recommends that genetic engineering might be considered as a method to develop new species for this purpose. At present, incineration provides the most complete means of disposing of many organic materials. NAS points out, however, that incineration has certain drawbacks. For example, it often requires emission controls and sampling and analysis of incineration products. If inorganic materials are present in the waste, slag and ash are produced as end products and must be disposed of. Unlike incineration, which requires an open flame, thermal methods use heat to treat hazardous waste. NAS mentions a number of techniques for this purpose: catalytic and reactive fluidized bed systems, molten salt reactors, plasma arcs and torches, microwave systems, and pyrolytic processes.-The only thermal method that has been used widely in industry is the pyrolytic process. Land treatment (which is distinct from landfilling) is another method that has broad potential, according to
NAS. In land treatment, the top layer of soil, approximately 1 ft, is mixed with the waste. Then, theoretically, chemical and biological reactions decompose part of the waste, part of it is adsorbed, and part of it, consisting of certain anionic inorganic fractions, migrates without causing violations of drinking water standards. For many wastes, pretreatment is ~ecessary before land treatment, to reduce the amount of land required and to reduce the amount of inorganic material in the waste. At present, ocean dumping of hazardous wastes violates some international accords. N AS and OTA note that the scientific community does not agree about the effects of ocean dumping and recommend that much more research be undertaken in this area. Except for studies of very specific materials in very specific areas, little is known about the effects of hazardous wastes on the ocean environment. Both NAS and OTA suggest, however, that ocean dumping be reconsidered for certain wastes. They believe that the ocean has the capacity to assimilate some kinds of hazardous materials without harm to human health or ocean life. As wastes are treated by one or more options in the hierarchy mentioned previously, their volume and toxicity are reduced. NAS and OTA agree that perpetual storage, the third step in the hierarchy, should be used for as few materials as possible. They recommend that after wastes, have passed through the first two steps in
the hierarchy, those nonreducible toxic wastes that remain should be buried, for the most part, in the deep subsurface, thereby isolating them from the biosphere. NAS notes that in the past, some wastes have been placed in abandoned salt mines and subsurface cavities. It reports that not enough research has been done to evaluate the safety of such disposal, but recommends that with adequate research, this method can probably be used. NAS especially recommends investigating the possibility of using the thick unsaturated zones underlying parts of the arid western U.S. These zones are free of water and could provide a large area for waste disposal. "The utility of these zones may be pivotal in providing a reasonable solution to the whole problem of disposal of hazardous waste," NAS reports. The committee also suggests that an inventory of possible permanent disposal sites be made. Risk assessment No method of waste disposal is entirely risk free. To determine the safest treatment for each type of waste, both N AS and OTA recommend the use of risk assessment. OTA cautions, however, that it should be considered an analytical tool for scientific input but not a means of providing a final regulatory decision. It also cautions that comparisons used in risk assessment must include the nature and impact of potential releases and not merely what percent of the hazardous material is removed or detoxified by the waste
FIGURE 1
The National Academy of Sciences recommends that wastes be'treated by one or more of three general methods comprising the treatment hierarchy In-plant options Recycle and reuse
Process manipulation
IConversion of hazardous to less hazardous or nonhazardous Land treatment
Thermal treatment
Incineration
Chemical, physical and biological
Ocean and atmospheric assimilation
•
Perpetual storage if
Landfill
Underground injection
Waste piles
Surface impoundments
Salt formations
Arid region unsaturated zone
Source: "Management of Hazardous Industrial Wastes: Research and Development Neec!s"; National Materials Advisory Board, Commission on Engineering and Technical Systems, National Research Council; National Academy Press: Washington, D.C., 1983
Environ. Sci. Technol., Vol. 17, No.7, 1983
283A
treatment system. OTA is especially critical of two risk assessment models developed by EPA to apply to the Superfund law and RCRA. The assumptions on which these models are based are so simplistic, OTA claims, "that their usefulness is questionable. For example, both models incorporate a concept that can result in unequal protection of some segments of the public," such as those who live in areas with a low population density. OTA and NAS agree that many technically feasible methods of managing wastes are not being employed to their fullest potential. They recommend that regional centralized facilities for waste treatment be built. Such facilities would separate the wastes according to treatment class and manage each in the most effective way. For small and medium generators, who may not be able to purchase the equipment required for ideal waste treatment, such facilities could provide an economical and relatively safe means of waste disposal. Examples of successful centralized waste treatment facilities in Europe, such as Kommunekemi in Nyborg, Denmark, are given. In Europe, landfills have been almost entirely phased out as a method of hazardous waste treatment. Changes in regulations The OTA report (see Table 1) points out loopholes in current waste regulations that leave certain hazardous wastes entirely unregulated and allow releases of hazardous waste to the environment. RCRA does not regulate small generators of hazardous wastes-those that produce less than 1 metric ton/yo Some of the wastes produced by small generators are highly toxic and are placed in sanitary landfills where no monitoring at all is required to detect leaks into groundwater. Wastes burned as fuel are also unregulated. These are considered recycled wastes and are not regulated under RCRA. Some of them contain highly' toxic materials that release hazardous substances to the atmosphere when burned. A third group of unregulated wastes is one that is omitted from EPA's definition. "A number of industrial wastes containing significant levels of dioxins, chlorinated organics or pesticides are not now regulated as hazardous wastes and cannot be shown to be toxic by EPA's test for toxicity," the OTA study says. It goes on to note that in addition to the 15 000 uncontrolled waste sites (Superfund sites) classified under the Emergency and Remedial Response Information System, created 284A
Environ. Sci. Technol., Vol. 17, No.7, 1983
under Superfund, there exist more than 80 000 contaminated surface impoundments (pits, ponds, and lagoons) in the nation. The potential threat of drinking water contamination is posed by at least 90% of these, according to an unpublished EPA report. There are few regulations for the control, monitoring, or cleanup of these sites. The OTA study recommends a number of regulatory changes that would close most of these loopholes. It recommends that the total exemption for hazardous wastes burned as fuel be ended. It also suggests that regulatory criteria should be established for hazardous wastes that do not fit EPA's current definition of toxic but are implicated as hazardous by a substantial body of scientific information (such as those having significant levels of dioxins or chlorinated organics). In addition, it states that certain hazardous wastes should be entirely banned from landfills, surface impoundments, and deep wells. EPA should be required to prepare a list of such wastes, OTA reports. (On March 17, 1983, EPA proposed two new rules that will close some of these loopholes.) Other regulatory changes that would discourage the use of landfills are also suggested. At present, Superfund is financed by a fee on chemical feedstocks, a so-called front-end fee. This fee provides industry with no incentive to reduce the volume of waste produced. OTA suggests that the Superfund monies be collected from a tail-end fee-a fee on the amount of waste produced. This fee would not be fixed for all wastes, but would vary according to the disposal method. "The underlying philosophy of this ap-
proach," OTA writes, "would be to reward those who minimize future risks and costs to society through the use of preferred aJternatives which permanently reduce the risks involved in hazardous waste management." Table 2 shows an example of a proposed hierarchical fee system. If the use of landfills were cut back by a large fraction, many new waste treatment facilities would be required. OTA suggests that a federal loan program could be instituted to provide low-interest loans to finance these facilities. OTA also recognizes that particularly difficult wastes would require R&D efforts to develop economic alternatives to landfill disposal. It advocates government support of private R& D projects in this area. Currently, EPA's R&D budget for hazardous waste disposal methods allots only 10% to the development of alternatives to landfills. Tn addition, the total proposed 1984 budget for the development of all hazardous waste disposal methods is 27% lower than the total in the estimated 1983 budget. Creation of new sites Both OTA and NAS point out that the RCRA and Superfund legislation are intimately related. Because the materials that are removed from Superfund sites are usually disposed of in landfills, and landfills have inherent problems no matter how well they are designed, we may be creating new Superfund sites in the process of cleaning up the old ones. Furthermore, landfills that are now active and run according to regulations could become future Superfund sites because no specific compounds are banned from them, and nearly all landfills will leak at some time in the future. OTA notes
TABLE 2
An example of a hierarchical fee system for hazardous wastes based on the amount generated and the disposal method Waste management category
Land disposal
Tax on solid waste (S/ton)
Tax on liquid waste (S/ton)
42
85
21 11
42
11 5
21 11
o
o
Off-site: Land disposal after treatment Treatment
21
On-site: Land disposal after treatment Treatment Recycling/reuse; used crankcase oil
Source: Minnesota Conference Report H.F. No. 1176, March 19, 1982.
that in 1985, (the year Superfund expires), more sites may need to be cleaned up than are now listed under Superfund as sites requiring attention. ' Also, the old Superfund sites may not be adequately cleaned up even when they are treated according to regulations. Current laws for cleanup provide no specific technical standard, such as concentration limits, for the extent of hazardous waste removal.
Key to progress
William T. Carnall, Editor Argonne National Laboratory Gregory R. Choppin, Editor Florida State University Reviews recent progress in plutonium chemistry. Reports on fundamental research as well as applied environmental and process chemical research. Covers physical-inorganic chemistry and spectroscopy, solution chemistry and behavior of plutonium in the aquatic environment, and separations chemistry. Includes introductory chapter by Glenn T. Seaborg, Nobel laureate and codiscoverer of element 94 and numerous radioactive isotopes. ,CONTENTS Plutonium Chemistry: The Beginnings. Magnetic Properties of Organometallic and Coordination Compounds • Reaction of Pu Metal with Diiodoethane • Bis(,u-hydroxo)tetraaquadiplutonium(JV) Sulfate • Superconductivity and Magnetism in Metallic Pu Systems • Pu Halides and Halogeno Complexes. Thermodynamics of Pu-Noble Metal Compounds. Thermodynamic Aspects of Pu-O System • Hypostoichiometric Pu Dioxide. x-Ray Photoemission Spectroscopy. PuFs Gas Photophysics and Photochemistry • Measurement and Interpretation of Pu Spectra • Stability and Electronic Spectrum of CSPUF6 • Pu Solution Chemistry • Pu(IV) Hydrous Polymer Chemistry • Pu Ions and Products of H20 Radiolysis. Stability Constants, Enthalpies, and Entropies • Photochemistry of Aqueous Pu Solutions • Behavior of Pu in Natural Waters. Aquatic Chemistry of Pu • Pu(IV) Ion in CarbonateBicarbonate Solutions. Ground-Water Composition and Pu Transport Processes • Overview of Pu Process Chemistry. Pu Process Chemistry at Rocky Flats • Pyrochemical Processing of Pu • Pu Production and Purification at Los Alamos • Carbamoylmethylphosphoryl Derivatives • Appendixes: Round Table Discussion; Pu Isotopes
Based on a symposium jointly sponsored by the Divisions of Nuclear Chemistry and Technolo~y and Analytical Chemistry of the Amertcan Chemical Society ACS Symposium Series No. 216 480 pages (1983) Clothbound lC 83-6057 ISBN 0-8412-0772-0 US & Canada $51.95 Export $62.95
Order from: American Chemical Society Distribution Office Dept. 24 1155 Sixteenth St., N.W. Washington, DC 20036 or CALL TOLL FREE 800-424-6747 and use your VISA or MasterCard.
No other issue affecting society has resulted in as wide a gap between the beliefs held by the public at large and the beliefs of scientists who are experts in the field. Progress in solving the hazardous waste problem rests in part on bridging this gap. "Public attitudes toward hazardous industrial wastes and their disposal,'" NAS notes, "include a number of misconceptions." ,There is a "general belief that hazardous waste generation can be eliminated,. that waste discharges can be avoided, and that waste disposal can be risk free. " The public also seems to believe that all hazardous waste disposal technologies present the same risks. On the other hand, some of the public's concerns about siting hazardous waste facilities are valid. Under current law, the community where the facility is located bears the risk and is subject to potential damages from such facilities, although society as a whole , enjoys the benefits (the products) associated with hazardous waste gener.. ation. Another problem is that the public does not trust the government to write good regulations or to enforce them strictly. This concern may be partially valid because hazardous waste regulations may be inadequate, and enforcement during the past few years may have been lax. Progress in siting hazardous waste facilities and in developing and using new technologies will thus depend on' several factors. One of them is public education to further an understanding of the technical issues involved. An.. other is creating and enforcing consistent regulations to protect both present and future generations. - Bette Hileman
Charles G. Gebelein, Editor Youngstown State University
David J. Williams, Editor Xerox Corporation
Rudolph Deanin, Editor Lowell University Focuses on the ways polymers can be used to construct efficient and durable solar energy systems. Points out the advantages in cost, weight, and variety of polymers and describes the problems of photodegradation. Sections include general solar applications, polymer photodegradation in solar applications, and photovoltaic and related applications. CONTENTS Applications and Opportunities • Economics of Solar Heating Systems • Film and Laminate Technology for Colfectors • Stability of Polymerip Materials in the Collector Environment • Reduction of Solar Light Transmittance in Collectors • Optical, Mechanical, and Environmental Testing of Collector Films • Protective Coatings and Sealants • Reactivity of Polymers with Mirror Materials • IR Reflection-Absorbance of Films on Metallic Substrates • Adhes',ves in Reflector Modules of Troughs • Solar Ponds and Liner Requirements • Flexible Membrane linings for Solar Ponds • Plastic Pipes for GroundCoupled Heat Pumps • Prediction or Photooxidation of Plastics • Photodegradation and Sorption and Transport of Water • UV Microscopy of Morphology and Oxidation. Novel Diagnostic Techniques for Detection of Photooxidation • Photodegradation of Poly(n-butyl Acrylate) • Stability of UV-Screening Transparent Acrylic Copolymers • Deformation and Low-Density Polyethylene Films • Luminescent Solar Concentrators • Encapsulation Materials for Photovoltaic Modules • Encapsulant Material Requirements • Encapsulant Degradation • Vacuum Lamination of Photovoltaic Modules • Polyacrylonitrile as a Photovo/taic Material • Polymeric Phthalocyanines • Photophysics of Doped Poly(2-Vinylnaphthalene) Films. Catalysis with Polymer Electrodes
Based on a symposium sponsored by the Divisions ofOrganic Coatings and Plastics Chemistry and Polymer Chemistry of the American Chemical Society ACS Symposium Series No. 220
Additional reading "Technologies and Management Strategies for Hazardous Waste Contro}"; Congress of the United States, Office of Technology Assessment, Washington, D.C., 1983. "Management of Hazardous Industrial Wastes: Research and Development Needs"; National Materials Advisory Board, Commission on Engineering and Technical Systems, National Research Council; National Academy Press: Washington, D.C., 1983
510 pages (1983) Clothbound LC 83~6367 ISBN 0-8412-0776~3 US & Canada $51.95 Export $62.95
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