Disposing of hazardous chemical wastes Faced with E P A cradle-to-grave regulations, industry is charged with management of its hazardous wastes. This was the subject of an ACS symposium sponsored by the Environmental Chemistry Division at the Spring meeting in Honolulu, Hawaii
Robert B. Pojasek Energy Resources Co. Inc. Cambridge, M a s s . 02138
Indiscriminate and long-term emplacement of waste chemicals in makeshift dumps has created serious global environmental problems. Many dump sites have been emblazoned by the media-Love Canal (Niagara Falls, NY), Valley of the Drums (West Point, KY), Toone Chemical Dump (Toone, TN), Silresim (Lowell, M A ) , to name a few. Other sites are literally waiting their turn to be brought to the public’s attention. Even modern, secured landfills have been questioned and closed by the public, such as the S C A Wilsonville Site in Illinois. An explosion closed the Rollin’s Logan Township facility in New Jersey and the public does not want it reopened. Statistics released by the Environmental Protection Agency (EPA) underscore the severity of the problem in the U S . There are over 32 000 dumps nationwide that contain some significant amount of hazardous waste. Perhaps as many as 2000 of these sites present potential imminent public health hazards. Adding to the problem are 35 million tons per year of new hazardous wastes generated by more than 270 000 generators. While there are presently an estimated 30 000 sites for treatment, storage or disposal of hazardous wastes, it is uncertain that many of these facilitie? will be able to meet the stringent regulations proposed under the Resource Conservation and Recovery Act (RCRA). 810
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Industry is concerned that it may be forced to assume an increasingly large share of the disposal task as offsite disposal contractors are forced to close. Many states are becoming involved in disposal-site operations as private waste management firms are beset by local opposition to new or expanded facilities. No matter who has control of the disposal, the cost of tighter reg.dation is expected to cost industry billions of dollars annually. Payments for past disposal indiscretions will escalate this figure substantially. RCRA is also attempting to prevent a practice known as “midnight dumping;” that is, hazardous wastes are dumped illegally along roadsides, down manholes, into waterways, and onto deserted plots of land. It is still unclear whether the waste generator can be absolved of responsibility for where the waste ultimately rests once it has turned the wastes over to a contract disposal operation. Whether the case involved midnight dumping or bankruptcy of the disposal firm, there have been too many instances where state governments have been left with no one to pay for cleanup operations. There is no question that the chemical industry is in trouble with these regulations. With intense public and governmental involvement, there is likely to be tougher enforcement of new and existing disposal regulations, an increasing shortage of permitted waste disposal sites, and a strong possibility that some waste disposal firms will be reluctant to handle wastes they deem politically sensitive. The dearth of disposal sites will create major technical, legal, and political problems
for the chemical industry. No longer can this industry, or others with significant hazardous waste generation problems, expect to maintain a low profile. Stiff fines and the liability of top corporate officials under R C R A regulations will demand immediate attention to the problems of chemical waste generation and disposal.
The symposium Because of the seriousness of the disposal issue and the impact it is likely to have on the chemical industry, the Environmental Chemistry Division of the American Chemical Society sponsored a symposium on this topic at the A C S / C J S Congress in Honolulu, Hawaii. The program featured talks by 40 distinguished speakers. A wide variety of disposal perspectives and technology options were presented by regulators, generators, disposers, and consultants. The symposium differs from the plethora of hazardous waste management conclaves in that the emphasis was placed entirely on disposal issues. This made it possible to cover this topic, with international participation, in greater depth than at any previous meeting. Participants from each stage of the hazardous waste disposal cycle enriched the discussions and everyone left with a new sense of purpose and some direction to take in ameliorating the problems that still must be faced. The symposium proceedings, which will be published as Volumes 3 and 4 of the Toxic and H a z a r d o u s W a s t e Disposal Series (Ann Arbor Science Publishers, Ann Arbor, MI) under the editorship of the author, will make the
0013-936X/79/0913-0810$01.00/0
@ 1979 American Chemical Society
material presented at the symposium available to those who were unable to attend. Three main features of the symposium were as follows: how hazardous waste legislation and practices in a number of countries affect disposal options; understanding differences in various perspectives on disposal options; and elucidation of technologies available for hazardous waste disposal. Significant excerpts from each of these areas are outlined below.
International activities Hazardous waste legislation in different countries has a direct impact on the selection and utilization of specific disposal technologies. Representatives of Germany, the United Kingdom, Australia, and the U.S. provided their views on the direction of hazardous waste disposal in their respective countries. In the Federal Republic of Germany, hazardous waste disposal is regulated by the Waste Disposal Law of 1972. J. Schmitt-Tegge described how the law mandates the establishment of numerous collection points for the wastes with and without pretreatment facilities. The actual treatment plants and disposal operations must be regionally based and handle more than 100 000 tons per year. Operation of the large regional facilities provides many advantages to each segment of t h P hazardous waste loop. Concern about the problems: from landfill sites in the 1 Kingdom led to the Deposit c sonous Waste Act of 1972. Alon this Act came the requirement tify the regulators of the dep, wastes. The passage of the Con Pollution Act of 1974 institutec itive" control of disposal with censing of sites. David Anderti cussed how this legislation i disposal in the United Kingdon I n Australia, legislation to c the ultimate disposal of haz:.,,,, wastes is implemented by the individual states. R. Connolly described that state and local government bodies share responsibility for the various aspects of the disposal of hazardous waste. A cooperative arrangement has been established between these groups and private industry. Gary Dietrich of the EPA briefly reviewed RCRA legislation in the US. H e pointed out that this statute does not address two increasingly important areas o f concern: administrative mechanisms to resolve the siting of hazardous waste facilities when adverse public reaction is encountered and effective means for remedying
public health and environmental damages that may arise from abandoned or inactive sites. Updates on Congressional activities on these topics were discussed, including the formation of a master fund to handle the cleanup of abandoned sites.
Japanese technology session In order to make information on Japanese disposal technology available to the symposium participants, a special session was arranged by Makoto Munemori (University of Osaka Prefecture). Makoto Hattori of Hiroshima University discussed the solidification of heavy metal-containing sludges by heating with silicates. Leach tests were applied to various formulations to determine the environmental adequacy of silicates as chemical fixation agents. O n e significant finding was that the addition of carbon to the glass markedly reduced the leaching of chromium from the powdered solids. T h e behavior of hazardous substances in the incineration and pyrolysis processes of organic wastes and in the stabilization and solidification processes of the inorganic wastes was described by M. Hiraoka of Kyoto University. It appears that cyanide is hard to chemically fix by cementitious solidification without any additives. Also, mercury and chromium ( V I ) comnounds need a laree amnunt of
Ultimate disposal of polychlorinated biphenyls by a catalytic hydrogenation-dechlorination method using a Raney nickel catalyst was explained by Yasuhiro Hatano of the Osaka Prefectural Research Institute. T h e stainless steel autoclave reaction vessel was neither corroded nor pitted because of the reduction conditions and the presence of an alkaline solution. The simultaneous removal of heavy metals from wastewaters and the disposal of the resultant sludge was described by Makoto Munemori. T h e process consists of oxidation with hypochlorite a t pH IO, subsequent reduction with excess iron (11) sulfate, and final precipitation of iron oxyhydroxide at pH 10. Although the resultant sludge has excellent leaching properties, it is often solidified with Portland cement for added disposal safety.
Perspectives Control over the hazardous waste disposal sequence in the U S . includes a myriad of components. Many of the groups involved in the disposal issue were represented in the symposium program. Other groups are included in the published symposium proceedings (Ann Arbor Science Publishers, Ann Arbor, MI). Their comments on the ultimate disposal problem are outlined below. The federal regulatory perspective was provided by John Lehman of the U.S. Environmental Protection
the most serious hcere are 103 sites" CIf
Agency. His group is responsible for drafting and implementing hazardous waste disposal regulations under Subtitle C of RCRA. Among the items covered in his presentation were the following: performance, design, and operating requirements for hazardous waste treatment, storage and disposal facilities; permits for these activities; and financial requirements for facility operation, closure and post-closure care. Implementation of this Federal program brings about a need for enforcement. Michael Kilpatrick, also with the U.S. EPA, described three tools to ensure compliance with the regulations. First is the authorization to inspect facilities that handle hazardous waste under Section 3007 of the Act. Second is the authority to provide for administrative compliance orders, civil action suits, civil penalties and criminal actions under Section 3008 of the Act. Finally, Section 7003 of the Act allows EPA to file suit to immediatelv restrain uersons from
Under the guidelines provided by R C R A , the states are responsible for implementing hazardous disposal regulations which are at least as stringent as those in the guidelines. The developing program in the State of Ohio was described by Donald Brown of Battelle Memorial Laboratories and R. Moffa of the Ohio EPA. A more advanced hazardous waste disposal program was described by Michael Miller of the Illinois EPA. The military is a major disposal of hazardous wastes. Thomas Hess of the U S . Army Environmental Hygiene Agency discussed the manner in which small waste quantities are disposed. When solidification is used, leaching and material stability tests are performed to determine the environmental acceptability of this disposal means. Waste management firms will have to meet the regulatory requirements as well as public pressure. Amir Metry of IU Conversion System (Horsham. PA) described how a disposal facility can meet short- and long-term environmental and public health safety goals. Enos Stover of Metcalf & Eddy (Boston, MA) outlined ways to handle safety and emergencies in hazardous waste management facilities. Industrial waste generators are also quite concerned over the developing waste disposal regulations. Dean Golden of the Electric Power Research Institute (Palo Alto, CA) told the symposium about a five-year multi812
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million-dollar research program designed to provide solutions to the disposal problems encountered by the nation's power-producing industry. The objectives of this exemplary program are offered to other industries as a base for developing their own programs. As you can imagine, the implementation of this complex set of regulations can create a host of difficult legal issues. According to James Feldsman of Boasberg, Hewes, Finkelstein and Klores (Washington, DC), all parties must become aware of their rights and must be properly represented as EPA and the states draw up and implement final rules.
Disposal technologies One thing was clear from the papers given to this point-there is no simple answer to the disposal problems. Effective disposal techniques are available, but have not been adequately applied in many cases. I n other cases.
inappropriate disposal technologies have been used for certain wastes with less than acceptable results. Unfortunately many state programs are placing too much emphasis on a limited number of disposal options; i.e., incineration and secured landfill facilities. Proper hazardous waste management involves the examination of the entire breadth of available options for each type of hazardous waste. The most economical option is selected for a particular case only as it does not compromise environmental suitability. A number of promising and established ultimate disposal options were discussed in the symposium. These options are divided into four categories: solidification, secured landfills, incineration, and other available technologies. Solidification The basis of this disposal option has been discussed in a previous article in E S & T (ADril 1978. D 382). There
the waste in a highly impermeable, inert matrix. Because permeabilities are often less than IO-' and structural strengths are great, solidified materials will often pass the tests described by EPA in Section 3001 of RCRA where the rau wastes would fail. In the first paper of this session, Dana Christensen of Battelle Pacific Northwest Laboratory (Richland, WA) discussed the adequacy of cementitious solidification agents and additives to fix trace metals in a low permeability mass. However, many chemical wastes contain organic and organometallic compounds. A new family of solidification materials is being developed to properly address this problem. These materials include epoxy resins, polymeric sulfur and others. Once a waste is solidified, it can be used for land reclamation. John Schofield of the Stablex Corporation (Radnor, PA) explained how an undesirable landform in proximity to the waste generator can be used in conjunction with a waste management facility to provide a suitable means for ultimate disposal. The eventual elimination of the nuisance quarry provides a positive siting advantage for the facility. It is difficult to secure a state's permission for land disposal of solidified wastes. Nina McClelland explained how the National Sanitation Foundation (Ann Arbor, MI) independently evaluated a solidification process for
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Hazardous waste control /cradle to grave
c.
Treatment
the State of Michigan. Waste samples were obtained and treated in the disposal vendor's pilot plant under the scrutiny of the N S F staff. Treated samples were subjected to two leachate testing procedures and the leachates analyzed for comparison to the raw sludges. Generally elutriate levels were a t or below the drinking water standard levels. There is a class of solidification agents which are thermoplastic, thus assuring solidification upon cooling. Richard Doyle of Werner and Pfleiderer (Waldwick, N J ) explained that besides asphalt, a number of other plastic binders can be used. These include polyethylene, polypropylene, urea formaldehyde and vinyl polyesters. Because the waste stream is fed with the molten binder into a n extruder/evaporator, considerable volume reduction can be achieved for aqueous feedstocks. An encapsulation technique based on the agglomerating of hazardous wastes and enveloping the agglomerates with a coat of high-density polyethylene resin was described by H. Lubowitz of T R W Systems (Redondo Beach, C A ) . T h e encapsulates were found to exhibit high performance and retention of the waste components
under a variety of applied mechanical and chemical stresses. Some hazardous wastes constitute larger volume waste streams. Uranium tailings represent one such waste. Robert Longfellow of Dravo Lime Compan) (Pittsburgh, PA) explains how pozzalanic-based materials can be used to effectively handle the radon gas emissions of this difficult-to-contain material. Solidification of wastes to form an impermeable liner and cap allow raw tailings to be placed in the landfill uith environmental adequacy and reasonable costs. Secured landfill A secured landfill is an ultimate disposal site, specifically designed to contain hazardous waste and minimize environmental contamination when operated properlq. These facilities are usually located in thick natural clay deposits where the hydraulic transport of leachate to an aquifer is unlikely. Section 3004 of R C R A has tightened the specifications on the siting. operation, closure and post-closure care of these facilities. Because of the random location of these sites and the exorbitant cost of engineering a site in a geologically unfavorable area, wastes are often transported great distances
for this form of ultimate disposal. Despite this fact. this alternative remains the most prominent method of disposal for a wide variety of hazardous wastes. Edward Shuster of Newco Chemical Waste System Inc. (Niagara Falls, N Y ) pointed out that the practice of secure landfilling goes far beyond the act of committing the wastes to the land. A well-run facility must include processes for selecting and evaluating appropriate candidate wastes, judicious use of treatment and solidification, and synergistic employment of cover media to achieve long-term integrity of the filled site. Robert Johnson of Browning-Ferris Industries Inc. (Houston, T X ) discussed the case histories of two BFI facilities. Site security and environmental monitoring practices are critical to ensuring environmental safeguards for the public. There are times when operating a regional waste management facility that one waste may be used to treat another waste. Mahendra Sandesara of Chemical Waste Management Inc. (Calumet City, IL) explained that industrial acid wastes react with baghouse lime to form a nontoxic slurry after air oxidation. The waste sets up Volume 13, Number
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into a solid within 45 minutes. Heavy metal wastes and arsenical wastes have been incorporated within this process, yielding a solidified and safely disposed product. Robert Stadelmaier of R C R A Research Inc. (Tonawanda, NY) discussed the state-of-the-art of in-situ treatment mechanisms. This technology includes the attentuation of deposited waste by maintaining or creating hazardous contaminant immobility. In this manner the in-situ detoxification of deposited wastes may be attained. Incineration Incineration offers a versatile tool in the management of organic hazardous wastes. It may be considered as a volume reduction process because the combustible fraction is converted to a gaseous form leaving only the noncombustible inorganic ash. Incineration is also a viable means of detoxifying many organic materials. Many incinerators can be operated as an energy recovery process when the heat generated is converted into steam and power or is put to some other beneficial use. This treatment and disposal method enjoys the popularity of hazardous waste managers because the basic process technology is available and reasonably well developed. However, this is not always the case for some of the more toxic chemicals such as PCB, dioxin, and Kepone. Incineration can be scaled to handle very large volumes of wastes without tying up large land areas. The primary disadvantages are that many organic wastes are seriously contaminated with volatile inorganic components (e.g., mercury, selenium, thallium, arsenic, etc.) which preclude the organics from being incinerated. This problem has often been overlooked in estimating the potential of incineration. Another problem is that combustion equipment tends to be more costly and complicated to operate (often with frequent downtime) than many other alternatives. Emission control devices are usually required for hazardous waste incineration. Proper disposal of the residues generated by this equipment and the ash generated in the incinerator must enter into the total hazardous waste management scheme involved in incineration. John Reed of the Illinois Environmental Protection Agency point out that the often-measured carbon monoxide concentration is not directly correlated with incinerator efficiency. H e presented an alternative approach based on first-order kinetics approxi814
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mations. Suggestions for checking the incineration operation and determining permissible ground level concentrations were also discussed. Destruction of hazardous wastes by oxidation with air in molten sodium carbonate was described by S a m Yosim of Rockwell International (Canoga Park, CA). Complete destruction of a number of combustible wastes was obtained. Neutralization of off gases and disposal of spent salts was also discussed. Because of the stringent environmental controls in effect for land-based incineration operations, ocean incineration has become more attractive. Max Halebsky of Global Marine Development (Newport Beach, CA) described a study on the economic and environmental viability of ocean incineration using a U S . flagship(s). H e concluded that this disposal option is both economically and environmentally viable. The operation of an incinerator for hazardous wastes may involve the storage of quantities of volatile and toxic chemicals. Major J . W . Tremblay of the U S . Air Force Occupational Environmental Health Laboratory (Brooks AFB, TX) described the land-based sampling protocol and industrial hygiene programs for the Herbicide Orange disposal operations. Other disposal technologies Deep-well disposal is a method of emplacing and storing liquid wastes in geologically acceptable reservoirs. Ray Amstutz of Williams Brothers Engineering Company (Tulsa, OK) explained that this disposal option is sufficiently developed, carefully controlled and environmentally acceptable. The investment and operating costs are usually quite low. Solid wastes may also be emplaced in geological formations. James Neiheisel of the US.EPA said that preferred site locations are in regions removed from catastrophic volcanic and seismic events. The formation should be homogeneous, dense, massive, and have assured hydrologic and mechanical stability. Host rock repositories may be located in salt, basalt, granite, shale or other material capable of isolating hazardous wastes from the biosphere. Existence of deep-sea technology, such as deep-sea bed drilling and emplacement and recovery of large equipment make it possible to consider disposing of hazardous and nuclear wastes in deep-ocean sediments. Rear Admiral Sonenshein (USN, Ret.) of Global Marine Development described
the advantages of this disposal technology as follows: remoteness from human activity, isolation capabilities of ocean sediments, large areas available, and avoidance of the problems of gaining access to adequate land sites. Composting includes the biological decomposition of hazardous organic wastes. Elliot Epstein of Energy Resources Co. (Cambridge, M A ) explained that the rapidity and extent of decomposition depends upon the chemical structure of the compound, composition of the waste matrix, the microbial environment and the optimization of parameters enhancing decomposition. Data exist to show the adequacy of this disposal alternative for a number of hazardous wastes. Biological degradation can also be achieved by incorporating solid and liquid wastes into the surface soil. The result of an EPA-sponsored state-ofthe-art assessment of soil incorporation technology was presented by David Ross of S C S Engineers (Long Beach, C A ) . Besides biodegradation, the processes of adsorption, dilution and inactivation also were present in the soil. However, the viability of hazardous waste disposal by soil incorporation is not clearly defined. Additional reading Pojasek, R. B., Stabilization, solidification of hazardous wastes, Enciron. Sei. Technol., 12, 382 (1978). Pojasek, R. B., Ed., StabilizationlSolidification Processes f o r Hazardous Waste Disposal, Ann Arbor Science Publishers, Ann Arbor, Mich., 1978. Pojasek, R. B., Ed., StabilizationlSolidification Options f o r Hazardous Waste Disposal, Ann Arbor Science Publishers, Ann Arbor, Mich., 1978. Pojasek, R . B., Novel approaches to hazardous waste disposal in New England, J . New Eng. Water Pollut. Control Assoc., April 1979 (in press). U S . Environmental Protection Agency, Incineration in Hazardous Waste Management, Publication No. EPAJ530J SW-141, Washington, D.C., 1975.
Robert Pojasek is the laboratory manager at Energy Resources Co. Dr. Pojasek has had extensice experience in eaaluating and analytically characterizing the encironmental consequences, especially to ground and surface waters, of hazardous waste disposal actiuities.
