July 20, 1979
Page 19895
THE TECHNOLOGY OF HAZARDOUS WASTE DISPOSAL
Mr. MUSKIE. Mr. President, it has been almost 1 year since the tragedy of Love Canal was disclosed. In that time the urgency of the hazardous waste disposal problem has not subsided.
The hazardous waste mistakes of the past have come back to haunt us at a time when Government is reluctant to initiate big spending programs, when industry is weary of regulation, and when the U.S. economy is already over-burdened with inflation. Nevertheless, these problems require effective, timely solutions.
We must respond to this frightening threat to health and the environment as soon as possible.
We must move aggressively toward addressing the existing problem sites and the many methods we use in disposing of our waste.
We now have several pieces of legislation before the Committee on Environment and Public Works which aim to correct the problems associated with the release of hazardous substances into the environment. The technology to safely dispose of hazardous wastes has existed for many years, but many promising innovations have recently been developed.
Our challenge now is to assure that any new legislation we enact, beyond the scope of the Resource Conservation and Recovery Act, will give industry the incentive to take advantage of these technologies in disposing of their wastes.
In recent months, Science magazine has published a series of timely articles summarizing the problems and promises of various hazardous waste disposal technologies. Mr. President, I request that these four articles be printed in the RECORD.
The articles follow:
TOXIC WASTE DISPOSAL A GROWING PROBLEM
(NOTE.— The Ward Transformer Company of Raleigh, North Carolina, paid $75,000 to Robert Burns, owner of Transformer Sales Company, to haul away and dispose of 31,000 gallons of transformer fluid containing highly toxic polychlorinated biphenyls (PCB's). Instead, according to a grand jury indictment, Burns dumped the chemicals along the side of 270 miles of North Carolina roads. The state is now trying to find a site to dispose of 30,000 cubic meters of contaminated soil.
Small firms throughout Kentucky hired the late A. L. Taylor to haul away toxic wastes generated during the course of their business. What they did not know, according to the Environmental Protection Agency (EPA) ,was that Taylor was dumping the barrels of waste on a 17-acre field at Stump Gap Creek, about 20 miles south of Louisville. When environmental officials discovered the site last year, it contained more than 100,000 steel drums, many of them rusted, dented, buckled, and riddled with gunshot holes. Federal officials estimate that it will cost $100 per drum to analyze their contents and dispose of them, but there is no money available.)
The highly publicized leakage of toxic wastes from industrial landfills such as the Love Canal area in Niagara Falls (see box) is only part of the story of toxic wastes. Legal dumpsites gone awry, tragic as they may be for the individuals involved, may not be the most serious problem with disposal of hazardous wastes. Illegally dumped wastes and incomplete and unsecured dump sites throughout the country represent a far more severe hazard, both because they are so numerous and because people who live near them are generally unaware of their existence.
It has become almost commonplace for investigators to find drums of chemicals of unknown ancestry hidden in abandoned warehouses, stored on small lots in run-down sections of cities, stashed under elevated roadways or in open fields beside them, poured onto the ground on vacant lots or rented farms, or simply dumped into municipal sewers and private wells. A substantial number of otherwise adequate industrial landfills have also been inadequately secured so that their integrity is highly questionable.
Hazardous materials at such sites can produce fires and explosions, contaminate ground and surface water, pollute the air, accumulate in the food chain, and produce poisoning, birth defects, and tumors. EPA has documented more than 400 cases of damage to health and the environment due to improper management of hazardous wastes, and that is but the tip of the iceberg; many times that number could undoubtedly be documented if EPA did not have such extremely limited manpower. EPA has been given broad new authority to regulate hazardous waste disposal under the 1978 Resource Conservation and Recovery Act (RCRA) , but critics argue that the agency has been slow to wield that authority. EPA officials, in turn, argue that great care must be taken in promulgating regulations for hazardous waste disposal because the subject is so different from anything that the agency has dealt with in the past. RCRA, furthermore, is oriented primarily toward regulation of new wastes and waste disposal sites and gives EPA only limited power to deal with existing situations.
Hazardous wastes — defined by EPA as those that are ignitable, corrosive, reactive, or toxic — account for 10 to 15 percent of all industrial wastes, or about 35 million metric tons per year. The total has been growing by about 3 percent annually. About 12 million metric tons of hazardous wastes are produced by the chemical industry itself, but significant amounts are produced by virtually every type of industry.
Some of the solid waste is recycled, some is burned, and some is dumped at sea (although that option will no longer be permitted after 1981), but most of it is simply burned in one of what seem to be innumerable landfills. There are now some 18,500 sites for disposal of municipal solid wastes, 23,000 for disposal of sewage sludge, and more than 100,000 for industrial wastes; uncounted others have already been closed. About 75 percent of hazardous wastes are disposed of on the propertyof the companies that generate them; the remainder is handled by waste disposal companies. Only 10 percent of all hazardous wastes are disposed of in a manner consistent with proposed federal regulations, according to EPA estimates. Nearly 50 percent is disposed of by lagooning in unlined surface impoundments, 30 percent in non-secure landfills, and about 10 percent by dumping into sewers, spreading on roads, injection into deep wells, and incineration under uncontrolled conditions.
There is no clear indication how many of these sites are dangerous. A recent report prepared for EPA by Fred C. Hart Associates,however, estimated that potentially significant health and environmental problems may exist at anywhere from 1,200 to 34,000 sites across the country.
Health problems, including "illnesses, injuries, poisoning cases, and deaths," were found at 232 sites studied by the Hart team in detail. They also found that 75 percent of all landfill sites are in areas "particularly susceptible to contamination problem" — in wetlands, on floodplains, and over major aquifers. The study estimated that it would cost more than $44 billion to eliminate totally the potential health dangers associated with the sites.
The haphazard management of dump sites must be considered especially astonishing in view of the potential longevity of many of the wastes. It is true that some of the more reactive chemicals will be degraded after a few months or a few weeks of storage. But the more stable materials, such as PCB's, may retain their chemical identity — and their toxicity — for decades, perhaps for centuries. Still other toxic materials are permanent hazards — a cadmium atom or a beryllium atom will remain that forever. From this perspective, the much-bruited half-lives of radioactive wastes from nuclear power plants seem almost transient. The volume of nuclear wastes also seems small in comparison. Only about 5000 metric tons of nuclear waste have been accumulated since the beginning of the nuclear era, four orders of magnitude less than the amount of toxic wastes generated in 1 year.
The design of most of the landfills now in use is not inherently bad. In essence, the approach is to construct an impoundment such that any liquids contained within cannot get out and external waters such as rain and groundwater cannot get in. In practice, this is achieved by enclosing the wastes in a basin with walls, bottom, and cap constructed of 3 meters or more of very dense clay; such clay has a permeability to water of about 1 x 10-7 centimeter per year. Such a vault should be very secure if it is not breached. Unfortunately, breaches seem not to be rare. An undiscerned crack in the clay, for example, can provide a much less resistant pathway for the migration of various chemicals. Earthquakes and other natural phenomena can produce cracks in the vault after it is sealed. Man's activities can also destroy the vault's integrity, as apparently was the case at Love Canal.
Far more threatening to life and the environment, however, are those chemicals that don't make it into secure landfills. Many of the activities of midnight dumpers, gypsy haulers, and some small companies border on the incredible:
The Union Carbide Corporation contracted with Nicholas Fernicola for disposal of 4500 55-gallon drums of organic wash solvents, distillation residues, and other organic wastes.
Fernicola abandoned the drums on a former chicken farm near Toms River, New Jersey, EPA says, telling the owners from whom he had leased the lot that the drums were empty. The owners subsequently discovered that the barrels were leaking chemicals into the ground. Two years after the barrels were removed to a secure landfill, traces of the chemicals were found in the aquifer that supplies local wells. Cleanup at the site and replacement of the water supply have so far cost Carbide $100,000 and the EPA more than $400,000. As in most other cases of this sort, civil lawsuits are still pending.
William J. Carracino, president of Chemical Control Corporation of Elizabeth, New Jersey, and other officers of the company have been convicted of, among other things, emptying a tank truck containing chemical wastes into Elizabeth Creek and into a sewer that leads into Newark Bay; abandoning drums of chemical wastes at various locations; and saturating dry garbage with toxic chemical wastes and hauling the contaminated garbage to landfills intended only for municipal garbage.
Salisbury Laboratories, which produces veterinary pharmaceuticals at a plant in Charles City, Iowa, has been dumping chemical wastes, principally arsenic, onto a 7-acre site since 1953, EPA says. Arsenic from the site is now being leached into the nearby Cedar River. The estimated cost of digging up the landfill and moving it is $30 million. The total worth of the company itself is only $5 million.
A plant producing fungicides and other mercury compounds operated for years, under several different owners, at a site about 2 miles north of the Meadowlands Sports Complex in New Jersey. During the manufacturing process, EPA investigators have found, as much as 2 kilograms of mercury per day was slopped onto the floor and washed into the swampy area outside the plant; much of it eventually entered Barry's Creek, which flows into the Hackensack River. A recent state investigation at the site showed concentrations of mercury as high as 123,000 parts per million in the creek and surrounding land; a dose of 160 parts per million is generally considered lethal and EPA restricts mercury concentrations in drinking water to less than 1 part per billion. Robert M. Wolf, a New Jersey realtor and land developer who bought part of the site in 1974 without knowing about the contamination, has already spent more than $2 million trying to contain the mercury, and it appears that a complete cleanup will cost at least another $6 million.
EPA's only authority to deal with such existing situations, says Steffen Plehn, deputy assistant administrator of EPA for solid wastes, comes under the "imminent hazard" provision of RCRA.
The agency can act only if there is an immediate danger to public health, he says, and such a danger is often difficult to prove. Furthermore, he adds, the agency has only very limited funds for work at such sites, and most of those funds were expended at Love Canal and in removing drums of chemicals from floodwaters at Stump Gap Creek.
Critics such as A Blakeman Early of Environmental Action and Leslie Dachs of the Environmental Defense Fund, however, argue that EPA has been reluctant to use its authority because top administrators at the agency have had no clear conception of how existing problems should be handled and because they have been more interested in developing regulations for the future. At the very least, such groups argue, inactive dump sites should be identified and the owners of the sites should have to meet at least minimum requirements for site security, monitoring, and postclosure care. Particular attention should be paid, Dachs says, to those existing facilities that would close down shortly before the proposed regulations take effect, and would thereby under the currently proposed rules be freed of future responsibility for the sites.
Plehn readily admits that the pressures of correcting errors committed in the past while at the same time trying to prevent future ones has often seemed to be beyond the resources of the agency, but he notes that the agency was specifically directed by Congress to address future storage problems. In the aftermath of Love Canal and other highly publicized discoveries of hazardous dump sites, however, EPA has had little choice but to become more vigorous in its attack on errors of the past.
The first fruits of that renewed vigor appeared in February when the Justice Department, in conjunction with EPA, filed suit against three companies, charging that they improperly dumped hazardous wastes at the Kin Buc Landfill in Edison, New Jersey, before the landfill was closed in 1976. The suit seeks $1.6 million in damages and penalties, permanent closing of the landfill, and action to halt leaching of the chemicals into the nearby Raritan River. The defendants in the suit are: Scientific Inc. of Scotch Plains, New Jersey, which operated the site through subsidiaries; Inmar Associates Inc. of Scotch Plains, which owns the land; and SCA Services of Boston, one of the companies that used the facility.
In a second suit, brought this month, the Justice Department has charged Eastern Rubber Reclaiming Company of Chester, Pennsylvania, and ABM Disposal Services Company with improperly storing hazardous wastes at a site in Chester. The suit would force the companies to clean up the site, at a cost estimated to be between $1.5 million and $3.5 million, and would prohibit further storage of hazardous wastes on the site. At about the same time, EPA deputy administrator Barbara Blum announced that EPA and Justice would join forces for investigation of about 300 dump sites per year, and that this could result in as many as 50 prosecutions per year. EPA is asking Congress for $131 million for 190 new personnel to investigate and do the legal legwork.
State governments are also beginning to move into the vacuum created by lack of EPA action. New Jersey has been in court trying to force Ventron Corp., a subsidiary of Thiokol Corp. of Beverly, Massachusetts, and Velsicol Chemical Corp. of Chicago, former owners of the plant near Berry's Creek that produced the mercury, to pay for the cleanup. Late in February, Michigan filed a multi-million-dollar lawsuit against Hooker Chemical Corporation in an effort to make the firm clean up wastes from its pesticide manufacturing plant in Montague. Chlorinated hydrocarbons from the dump, Michigan contends, have contaminated some private water wells and are seeping toward nearby White Lake. These states and others are said to be contemplating similar suits to force cleanup of other disposal sites, and some sources within the chemical industry speculate that the industry may be facing an onslaught of lawsuits unlike any ever seen before.
Congress may also take action against existing sites. At a February meeting of the Manufacturing Chemists Association, Representative James J. Florio (D-N.J.), chairman of the House Subcommittee on Transportation and Commerce — which has jurisdiction over RCRA — told the group that he will "convene hearings, summon witnesses ... and present a Congressional proposal" for cleaning up and minimizing the danger from inactive dump sites. More recently, Representative Robert Eckhardt (D-Tex.), chairman of the House Commerce Committee's Investigations Subcommittee, sent out very detailed questionnaires to the 50 largest U.S. chemical manufacturers to attempt to learn where inactive sites are located and what they contain. The subcommittee wants the information by the end of June.
Congress may also act to provide funds for cleaning up abandoned sites. One proposal favored by EPA, environmental groups, and some members of Congress would create a "superfund" from taxes on petroleum products and chemicals. In one proposal, refineries would be charged up to 3 cents per barrel of oil received, chemical-processing facilities would be charged as much as 60 cents for each barrel of refined petroleum products used (or for an equivalent quantity of natural gas), and companies that ship materials such as arsenic, mercury, and chlorine would be charged as much as $5 per ton. Other proposals would place taxes on companies that dispose of hazardous wastes. In any case, the fund would grow at a rate of $300 to $400 million per year until it reached $6 billion. The fund would be used, however, only if the cost of cleanup could not be recovered through lawsuits and other recourses.
As pressing as the problems of existing hazards may be, it is perhaps even more important to ensure that future hazardous wastes are handled in an acceptable manner. To that end, EPA has during the past year proposed seven major sets of regulations and guidelines for disposal of hazardous wastes. These cover: definition of hazardous wastes; standards of operation for generators and transporters of such wastes; standards for storage, treatment, and disposal facilities; a permit system for companies that transport, treat, store, and dispose of hazardous wastes; guidelines for development of hazardous waste programs by states; and establishment of a notification system for wastes.
The heart of the program involves what is known as "cradle-to-grave" monitoring of hazardous wastes. Any company that produces more than 100 kilograms of hazardous wastes per month will be required to provide manifests for all hazardous materials that are to be disposed of offsite.
Any company that transports the waste must carry the manifest with the wastes, get it signed at the disposal site, and send a copy back to the generator. The company that disposes of the wastes must do the same. In this fashion, the waste generator will be able to follow the progress of the material to ensure that it is properly disposed of, and EPA will be abe to monitor the whole operation. Critics such as George Kush of the National Solid Wastes Management Association, however, argue that this proposed rule is too lenient, and that it should be extended to cover all companies that dispose of wastes offsite.
Other provisions of the new regulations require operators of disposal sites to monitor them continuously during their operation and for 20 years after the sites are closed. The operators must also assume liability for as much as $10 million in damages for any incident resulting from operation of the site. Regulations covering this type of financial liability are a new concept for both EPA and the federal government, Plehn says, and the deliberations involved in creating them were part of the reason it took so long to issue the regulations.
EPA estimates that the cost of the new regulations for the 17 major industries affected will be $750 million, or about a third of a percent of their total sales. Some industry sources contend the cost could go as high as $25 billion, but that figure seems clearly to be exaggerated. Whatever the ultimate cost, EPA clearly hopes that an increased cost of waste disposal will lead to a decreased generation of wastes and to increased recycling of the valuable materials found in wastes. It should also enhance the attractiveness of other, more acceptable disposal techniques, such as controlled incineration, chemical and biochemical treatment, and solidification. EPA's goal, Plehn says, is that disposal in landfills should be used only as a last resort.
Enforcement of the new regulations will not begin until mid-1980. A coalition of environmental groups had filed suit in federal court seeking speedier implementation, but the judge ruled that EPA had been proceeding in good faith and as fast as practicable. Meanwhile, some 41 states have sought, and are expected to receive, interim authority to conduct their own hazardous wastes programs under a section of RCRA that allows EPA to delegate much of its authority. A few have already enacted their own laws. New Jersey. California, and Illinois, for example, already operate manifest systems for hazardous wastes, and New Mexico is expected to begin one soon. New York and Michigan are also considering construction of state-operated disposal facilities, and New York recently established a commission to select sites for landfills.
Regulations in other states are generally less stringent, however, and that is creating problems for both the states and the industries. Industrial facilities in states with restrictive laws on waste disposal suffer a competitive disadvantage, says New York State health commissioner David Axelrod, because their counterparts in states with less restrictive rules can manufacture products more cheaply. The states are also hurt, he adds, because industries will gravitate to states with fewer restrictions. EPA administrator Douglas Costle, however, argues just the opposite. He thinks industries will build their new facilities in states with restrictive disposal laws in hopes that this will limit their potential liability if their disposed wastes should ever become an environmental or health hazard.
In any case, disparities in the law will probably lead to a greatly increased transport of toxic wastes — with the attendant hazards. Already, hazardous materials that require the most expensive disposal techniques in states like New York and New Jersey are being transported to states such as Ohio with less restrictive requirements. Rhode Island, says Ronald Buchanan of New Jersey's Department of Environmental Protection, "has become the Mecca for hazardous and chemical wastes disposal" in the East because it will accept all types of waste for landfills at minimal cost.
The states are thus pushing for EPA to accelerate implementation of its hazardous wastes regulations. Industry has the same goal because it would like to operate under uniform laws throughout the country. Legitimate waste disposal companies favor the new regulations, and would like even stronger ones, because the laws can only increase their business. All three groups would like to see EPA extend its authority even further in some cases; in particular, they would like the agency to take some of the heat off local governments by giving its imprimatur to new landfill sites. About the only groups that think the new regulations are too restrictive are the midnight dumpers and the gypsy haulers.
AN ENVIRONMENTAL TIME BOMB GONE OFF
Landfills for chemical wastes have frequently been called ticking time bombs. It is no surprise, then, that Love Canal has been called "an environmental time bomb gone off." The bomb analogy is particularly appropriate because, today, the Love Canal area of Niagara Falls looks like a war zone. The 235 houses nearest the landfill are boarded up and empty, surrounded by an 8-foot-high Cyclone fence that keeps tourists and looters away. Still other houses outside the fenced area are also boarded up and deserted, their owners having fled the unknown. Here and there throughout the surrounding neighborhood, newly erected green signs mark the pickup points for emergency evacuation in case there is a sudden release of toxins. An ambulance and a fire truck stand by in the area at all times as construction workers struggle to seal off the flow of chemicals and render the area once again safe — if not exactly habitable. The scene offers mute testimony to the hazards of improper storage of toxic wastes.
Love Canal takes its name from William T. Love, a 19th-century visionary who attempted to create a model city and industrial area near Niagara Falls to take advantage of the area's cheap hydroelectric power, which at that time could not be economically transmitted over long distances. The keystone of the project was to be a navigable canal connecting the Niagara River above and below the falls. His vision was shattered by recession and by Louis Tesla's discovery of a cheap way to transmit electric power long distances. All that remained of his vision was a partially dug section of canal in the southeast corner of the City of Niagara Falls.
Industry was also attracted to the area by the abundance of electric power and water and, in the 1920's, the partially excavated section of canal became a chemical and municipal disposal site for several chemical companies — most notably the Hooker Chemical Corporation — and the city itself. About 21,800 tons of chemical wastes were deposited in the canal before it was closed and covered with a clay cap in 1953.
The seeds of tragedy were sown in the late 1950's when about 100 homes were erected immediately adjacent to the landfill and an elementary school was constructed on top of it. Excavations associated with the construction and the underground installation of utilities apparently damaged the integrity of the cap. Water from the heavy rains and snows of the last few years filled the clay basin holding the chemicals to overflowing, and the chemicals began oozing to the surface and seeping into basements of the adjacent homes. Residents of the area began to notice pools of thick, black sludge on the ground surface, noxious odors, and symptoms of respiratory distress.
Their protests finally caught the attention of authorities and, last April, after investigators had found evidence of toxic chemicals in several homes, then-state health commissioner Robert P. Whalen ordered a complete study of the area. These studies showed that hazardous levels of many toxic chemicals existed in the basements of homes adjacent to the site — but fortunately not in the living areas of the houses — that young women in certain areas around the canal had as much as three times the normal incidence of miscarriages, that children born to families in the same area had as much as 3.5 times the normal incidence of birth defects, and that many of the adults showed incipient liver damage.
On 2 August, Whalen declared an imminent health hazard in the area, closed the elementary school, and recommended the evacuation of children under the age of two and pregnant women from the ring of homes surrounding the canal. A week later, New York Governor Hugh L. Carey announced that the state would purchase the 235 homes nearest the landfill, evacuate the families, and find new homes for them. Subsequently, President Jimmy Carter declared the zone a disaster area, qualifying the families for federal assistance; this marks the only time such a proclamation has been issued as the result of a chemical disaster. All of the families in the immediate vicinity of the canal were moved by the end of the year, and subsequent studies have shown that the liver damage has been reversed and that the individuals are generally in good health.
As the studies have continued, investigators have found evidence that more than 300 chemicals are present in the soil and homes and have identified more than 100 of them. David Axelrod, the present state health commissioner, estimates that as many as 10 percent of the chemicals may be mutagens, teratogens, and carcinogens. Traces of the chemicals have been found as far as several blocks from the site and in the Niagara River on one side of the site and the Black Creek on the opposite side. Some chemicals are believed to have flowed to these locations through underground stream beds that crossed the site, some may have been tracked by vehicles, and some contaminated soil may even have been dumped in the creek during construction in the area.
In view of these findings, Axelrod recently recommended evacuation of all children under the age of two and pregnant women who live within six blocks of the site. Other investigators, such as Beverly Paigen of Roswell Park Memorial Institute, argue that a much larger evacuation should be carried out because of the potential hazard.
Meanwhile, public health authorities are digging trenches 2 to 4 meters deep along both sides of the canal and installing perforated drainage pipes surrounded by gravel. These pipes will collect groundwater contaminated by the chemicals and direct it to an onsite facility where the chemicals will be adsorbed onto activated carbon. The entire landfill is also being capped with a new layer of clay to prevent any more water from entering the basin. The cost of the cleanup is estimated at more than $30 million; but lawsuits resulting from the incident now total more than $2 billion.
The fate of the elementary school and the houses closest to the landfill has not been decided yet, but it seems likely that they will be either moved away or leveled. Even if the landfill should be secured, it is not likely that anyone will want to occupy the buildings again.
HAZARDOUS WASTES TECHNOLOGY IS AVAILABLE
Suppose that, after you've finished reading this magazine, you had two choices for its disposal: you could put it in the garbage can for disposal with the rest of your trash, or you could mail it to a special collection center at a cost of 50 cents. The choice, for most people, is obvious. Now suppose that the ink with which it is printed contains a contaminant that might harm the environment if it escapes from a conventional sanitary landfill, but that can be detoxified at the special collection center. Suddenly the choice becomes much more difficult. Is the potential for harm to the environment of greater importance than the extra $26 per year in mailing costs? Suppose the mailing cost is $2 per issue and the scientist in the laboratory down the hall, who doesn't mail in the magazines, can get a competitive advantage over you with that extra $100 per year?
That, in simplified terms, is the moral and financial dilemma that has in the past faced generators of hazardous wastes. Acceptable ways to deal with such wastes have been available for many years, and the number of alternatives continues to grow, but the cost of such alternatives is almost always much greater than that of less desirable methods. Disposal of hazardous wastes in an unsecured landfill might cost as little as $5 per ton, for example, whereas a desirable alternative such as incineration might cost as much as $300 per ton. In a highly competitive business atmosphere, the one company in an industry that adopts acceptable disposal procedures does so at the risk of being priced out of business.
The new regulations on disposal of hazardous wastes issued by the Environmental Protection Agency (EPA) under the provisions of the Resource Conservation and Recovery Act (RCRA) promise to ease those dilemmas for many companies. By forcing all companies within an industry to use acceptable disposal techniques, the regulations remove any competitive disadvantage associated with such use. The chief problem remaining now for the industries is selection of the most advantageous disposal technique from among the many available The chief problems for the government are enforcement of RCRA and overcoming citizen resistance to disposal facilities. Everyone seems to agree that disposal facilities must be built, but no one wants one near them. This citizen opposition has greatly complicated the construction of landfills, incinerators, and other facilities and has, perversely, contributed to the continuation of less acceptable disposal practices at facilities that are already in existence. Even the best technology is no good if it cannot be put into use.
Clearly, the ideal solution to the hazardous wastes problem is to change industrial processes so that hazardous byproducts are not produced or, if that is not feasible, to extract hazardous materials from the waste streams and use them as raw materials. In the past, the cost of recovery of such materials has generally been much greater than the cost of new materials, and this option has been little used. The increased costs of disposal mandated by RCRA, though, provide a strong incentive to reduce the waste load and recover as much of the wastes as possible. This pressure for recovery is abetted by the increased cost of raw materials, particularly petrochemicals.
Joan Berkowitz of Arthur D. Little, Inc., cites one manufacturer who, a short time ago, was anxious to dispose of distillation residues from the production of ethylene glycol. When asked about the residues recently, however, his reply was, "What wastes?" Another good example involves recovery and reuse of polyvinyl alcohol, an agent used in the textile industry for sizing yarns before they are woven into textiles. Previously, the alcohol was scoured from the cloth before the cloth was dyed, and was released into the environment. Investigators at J. P. Stevens Company Inc., Clemson University, Gaston County Dyeing Machine Company, and Union Carbide Corporation developed a hyperfiltration process for recovery of as much as 96 percent of the alcohol from the effluent stream. This, says Stevens, prevents about 2.2 million kilograms of nonbiodegradable polyvinyl alcohol from being released into the environment each year.
In general, recovery techniques are both process- and material-specific, so that a generalized discussion is all but impossible. Encouraging such recycling is the number one goal of EPA, however, says deputy assistant administrator Steffen Plehn, and the agency hopes that such processes could reduce the total hazardous waste load by as much as 20 percent.
Even if the company that generates the wastes is not able to use them, they might be useful to someone else. Waste solvents produced by the electronics industry, for example, are of higher quality than virgin materials used in many processes less sensitive to impurities, Berkowitz says.
Competitiveness and secrecy within industry, however, make it difficult or impossible for one company to know what is available from another. One way to overcome this problem is with a waste exchange or clearinghouse in which available materials are listed without identifying the source. Until about 1975, the only waste exchange in this country was operated by the St. Louis Regional Commerce and Growth Association, although the concept was fairly common in Europe. In that year, EPA commissioned a study of the concept by Arthur D. Little, concluded that it was viable, and began promoting the formation of such exchanges.
As many as 40 exchanges were established within the next few years, but many of them failed after a short period of operation. A major reason for failure, according to Harry Trask of EPA, was the involvement of state and local governments in their operation. Many companies simply refused to provide information to the exchange for fear that it would end up in what they considered "unfriendly hands." In many cases, though, the organizing group also did not follow through with the necessary effort to make the exchange a success.
Today there are about 20 clearinghouses in this country and one in Canada. They are operated by trade associations, chambers of commerce, universities, and — in states where confidentiality can be maintained — by state and local governments. A few are also operated as profit-making ventures. The most common types of materials listed by the exchanges are solvents and oils, paper, wood, scrap metals, and surplus chemicals. In most cases, the clearinghouse simply provides an updated listing of available materials and forwards inquiries to the company that listed them; the exchange or purchase is then handled by the participants. In a few cases, though, most notably in a program operated by the state of California, the clearinghouses actively try to arrange exchanges or sales.
Because of confidentiality and the passive role of most of the clearinghouses, it is difficult to monitor the amount of material that changes hands. The St. Louis clearinghouse, though, estimates that about 10 to 15 percent of the listed materials actually change hands. Translating those results nationwide, EPA's Trask estimates that about 3 percent of all industrial wastes could be recycled in this fashion. The number of clearinghouses is growing by three to four per year, however. With more clearinghouses and increased pressure from RCRA regulations, EPA hopes the percentage of hazardous wastes recycled will at least be doubled by 1985.
If the wastes cannot be recycled, they can often be detoxified by relatively simple chemical treatment. Such treatment can either render the material completely innocuous or substantially reduce the volume that must be disposed of. Like recycling, chemical treatment is material- specific, but some generalizations can be made.
The most common technique for chemical treatment, according to Alexandra Tarnay of EPA, is pH adjustment or neutralization. Pickle liquors from electroplating and other metal-finishing industries, for example, are much too acidic to be discharged into the environment.
Neutralization with lime or some other inexpensive alkaline material may make them safe for discharge. Neutralization has the additional advantage of precipitating heavy metal irons in the liquors as insoluble hydroxide salts, which can be removed from the waste stream by settling or filtration. The free liquid can then be discharged and the much smaller volume of hydroxide salts disposed of in a landfill or by some other method. The iron and steel industry, for example, frequently uses neutralization and precipitation to remove iron and other metal ions from waste streams.
Oxidation and reduction reactions are also frequently used. Waste streams containing cyanides, for example, are oxidized with sodium hypochlorite or a mixture of sodium hydroxide and chlorine to produce carbon dioxide and nitrogen. Similarly, toxic chromium-VI ions in a waste stream can be reduced to less toxic chromium-III ions with sulfur dioxide. Many other materials can also be treated with oxidizing or reducing agents to render them harmless or less toxic.
The volume of waste streams can frequently be reduced significantly before disposal or further treatment by evaporation from a holding pond, vacuum filtration, or heating. Water is frequently removed from waste streams produced in the manufacture of photographic chemicals, for instance, by evaporation. So-called black and sulfate liquors from the paper industry are commonly concentrated by contact with hot flue gases before the liquids are incinerated.
Other chemical treatment processes are also useful, but are less common. Absorption on activated carbon, for example, can be used to remove some types of organic materials from dilute waste streams. The organics can sometimes be removed from the carbon and recycled, but often both the carbon and the organics are incinerated. This technique is sometimes used in the food processing industry and to remove dyes from waste streams in the textile industry. Ion exchange chromatography can also be used to remove various ions from waste streams, but its use is limited by its relatively high cost. It is sometimes used, however, for removal of chromium ions from certain types of plating baths. The various types of chemical treatment processes together are probably used on some 5 to 10 percent of hazardous wastes in this country.
Chemical treatment can often be a more efficient process if it is performed by someone other than the company that generates the wastes. Regional waste disposal centers in West Germany and some other parts of Europe, for example, generally use an alkaline waste from one company to neutralize an acidic waste from another company. Similarly, a waste stream containing cyanide might be used to reduce chromium-VI in another waste stream. In this manner, valuable raw materials are not used to detoxify wastes, and the overall cost is cheaper. A similar approach is used by some waste disposal companies in this country, such as SCA Services Inc. of Boston, but the total amount of wastes that they treat is very small.
For many types of wastes, particularly nonchlorinated organic wastes, biological treatment is an acceptable alternative. The most common type of biological treatment is soil incorporation, also known as land farming. The spreading of organic wastes such as animal manure, crop residues, and sewage onto agricultural land to supply plant nutrients is an ancient one. Extension of the practice to other types of organic materials, however, is a phenomenon of the last 20 years, pioneered primarily by the petroleum industry. In general, the practice involves four basic steps: application of wastes onto or beneath surface soil; mixing the waste with surface soil to aerate the mass and expose the waste to soil micro-organisms; addition of nutrients, when necessary; and remixing the soil and waste mass periodically to maintain aerobic conditions.
EPA recently issued proposed regulations governing land farming; these are based largely on a study conducted for the agency by David E. Ross and Han T. Phung of SCS Engineers Inc. in Long Beach, California. That study concluded that land farming is an acceptable technique for management of various types of wastes if suitable constraints are imposed. Among other things, the farmed area should be at least 1.5 meters above the historical high groundwater table; it should be at least 150 meters from water supplies; erosion potential should be minimal; and annual rainfall should be low to prevent formation of an anaerobic mire. Most important, Ross and Phung argue, the soil itself should be monitored regularly to a depth of 1 meter to detect any downward migration of trace metals or other contaminants. Previous investigators had assumed that groundwater should be monitored, but by the time contaminants reach groundwater, Phung says, it may be too late to prevent environmental deterioration.
Because of these constraints and the need for large areas of land, land farming has been most successfully practiced in semiarid regions of the west. Materials that have been successfully land farmed include sludges frcm paper mills and fruit canneries, sewage sludge, pharmaceutical wastes, and some organic chemical wastes. The city of Odessa, Texas, even used the technique for municipal refuse, but the amount of land required was very large and the area was very unsightly. By far the greatest amount of experience with land farming, however, has been obtained with petroleum refinery sludges.
Petroleum companies such as Exxon and Continental Oil have practiced land farming for 10 to 15 years. Typically, sludge is spread on the soil in a layer 7 to 15 centimeters thick, according to R. S. Lewis of Exxon. After water is allowed to evaporate for a few days, the sludge is disked into the soil and, if necessary, other nutrients are added. When the oil content in the top centimeters of soil has been reduced to about 2 to 4 percent, another application can be made; generally, this reduction requires about 2 months. At one typical Exxon refinery in Baytown, Texas, Lewis says, sludge was applied at an average rate of 1008 tons per hectare per year.
Extrapolating from these and other data, SCS estimates that about 3 percent of all industrial wastes in this country could be disposed of by land farming, at a cost of about $5 to $22 per cubic meter, exclusive of transportation costs. That price compares favorably with the cost of incorporation in landfills.
Land farming is not appropriate for wastes that contain significant quantities of heavy metals or other materials that are not biodegradable and that would thus accumulate in the soil. This problem might be overcome, though, by conducting the process in a closed system. Charles V. Hall and his colleagues at Iowa State University, for example, have been experimenting for more than 10 years — the last three in cooperation with EPA — with degradation of pesticides and other organic materials in a concrete-lined pit. The pit is approximately 4 meters by 8 meters, a little over a meter deep, and filled with gravel and soil; it is equipped with a cover that closes automatically to prevent precipitation from filling the basin. Aqueous solutions of pesticides or organics are simply placed in the pit; the water evaporates away and the organic component is degraded by the same types of microorganisms that are active in land farming.
In a typical warm season from May through October, Hall says, the pit can handle 6,000 to 7,000 gallons of waste. The system can be scaled up to handle much larger volumes of wastes, he says, and the cost should not be substantially greater than that of land farming. If the wastes contain nonbiodegradable contaminants, he adds, they will be greatly concentrated in the soil in the pit and can subsequently be conveniently disposed of. The group is now looking for more efficient microorganisms, and is studying the concentrations of volatile organics in the air over the pit to ensure that there is no hazard.
The rate of biodegradation can be speeded up if the temperature of the wastes is raised; this can be achieved by aerobic composting, says Eliot Epstein of Energy Resources Company Inc. of Cambridge. Thermophilic bacteria thrive and multiply at temperatures of 45º to 80º C. in the compost piles favored by organic gardeners, and similar conditions can be achieved in an industrial setting. The principal requirements are containment, protection from precipitation, and use of a bulking agent so the system remains porous and aerobic. The economics of the process, Epstein says, depend on the cost of the bulking agent; the cost could be kept low, he adds, by using straw, ground-up waste paper, or agricultural wastes.
Decomposition of wastes in composting is significantly faster than in land farming. DDT wastes have been 64 percent degraded in as little as 50 days, Epstein says, and organophosphorous pesticide wastes in as little as 2 weeks. The system is also versatile. Tests by the U.S. Army, Epstein notes, have shown that composing can be used to degrade TNT wastes. Pesticides, phenols, and aromatics are among other materials for which the system is suitable. Energy Resources is also investigating composting of oily wastes under a contract with the U.S. Coast Guard.
Composting is already used for sewage sludge and for cellulosic wastes in the pulp and paper industry. The Blue Plains Sewage Plant in Washington, D.C., for example, now composts as much as 275 tons of sludge per day. Costs vary widely, depending on individual circumstances.
Pulp and paper mills have found that the technique is cheaper than land-filling, but composting of sewage sludge costs $30 to $100 per ton of dry materials. Some of this cost can be recovered by selling the product as a soil conditioner, but this market may not be large.
The viability of composting for disposal of other types of materials may be demonstrated by Hoffman-La Roche Inc. That company has been experimenting for several years with composting of pharmaceutical wastes at its plant in Belvidere, New Jersey, and is now requesting permission from the state to conduct a large demonstration project that would be the first industrial application of composting for anything other than paper products or sewage sludge. If their demonstration is successful, Epstein says, other companies are very likely to follow suit.
Recycling, chemical treatment, and biodegradation are the least controversial and most acceptable methods for disposal of hazardous wastes. Their primary advantage is that the waste material is either used or destroyed, so there is no further need for containment or monitoring. Of all disposal techniques, they alone have met little citizen opposition to siting of facilities — the recycling and treatment processes because they are more or less conventional industrial processes, and land farming because the sites have generally not been near communities. That situation could change if compost facilities sited near cities should produce noxious odors, but such a development should be preventable with care. The chief disadvantage of the techniques is that they are applicable to only a limited percentage of hazardous wastes. Despite the desirability of these approaches, other techniques must be found for the majority of wastes.
INCINERATION, DEEP WELLS GAIN NEW IMPORTANCE
The thought of incineration, to many people, brings forth images of municipal incinerators spewing out clouds of dark smoke, noxious fumes, and uncountable other pollutants.
Unfortunately, this remembrance of things past obscures today's reality. Given the proper controls, incineration can be the safest, cleanest, most effective way to dispose of hazardous wastes. If only short term costs are considered, though, it is also the most expensive. This cost has, in the past, limited the use of incineration to perhaps less than 3 percent of all hazardous wastes, but the increasing costs and potential liabilities associated with other techniques are making controlled combustion much more attractive.
Distillation residues, oily wastes, chlorinated hydrocarbons, pesticides, and a varietyof other materials can be incinerated with relative ease. In some cases, the waste can be mixed with other fuels and burned for its heat content; distillation residues and solvents are the most common materials for which this is the case. In many instances, however, other fuels must be added to the wastes to ensure their complete destruction. There has generally been little or no effort to recover the energy produced in combustion, but the Environmental Protection Agency (EPA) and industry are becoming more interested in this possibility because it would reduce the cost of disposal.
The most important advantage of incineration is that it completely destroys wastes so that there is no cost associated with future monitoring and no future liability. For the process to be safe, though, few molecules of the hazardous material can be permitted to escape up the chimney.
EPA regulations thus require at least 99.99 percent destruction of the wastes. This, in turn, requires sophisticated technology. A modern incinerator that handles some solids typically combines a rotary kiln with a secondary combustion chamber to assure complete destruction. The
incinerator must be equipped to trap particulates given off during incineration and, if it processes chlorinated hydrocarbons and similar materials, it must have a scrubber to remove halogens and other pollutants from the flue gas.
Because of the equipment required, incineration is expensive. Steven C. Siegel of SCA Services Inc. of Boston estimates that a small, privately owned incinerator now costs $0.5 to $1 million, while a commercial-scale facility can cost upwards of $30 million. Incineration costs thus average about $110 per ton, according to one report prepared for EPA, but can reach several hundred dollars per ton for highly chlorinated materials.
There are about 15 hazardous waste incinerators throughout the country. Most of those are small units operated by corporations — most notably the Dow Chemical Company, which has been burning wastes for more than 40 years — for disposal of their own wastes, but about half a dozen are commercial facilities. Rollins Environmental Services of Wilmington, Delaware, for instance, operates three commercial incinerators and is considered one of the biggest proponents of combustion. Industry sources note, though, that Rollins operated the facilities at a loss for several years because of insufficient volume. The company has also encountered continuing opposition from environmental officials in the communities where the incinerators are located because of fears about the potential for emissions of hazardous gases. Siegel predicts that there will be no more large commercial incinerators constructed until EPA demonstrates a commitment to enforcement of its proposed regulations governing disposal of hazardous wastes — and thereby guarantees a market for the new facilities, even if the cost of incineration remains higher than that of other alternatives. Siegel and other industry officials also argue that EPA should play a greater role in the siting of new incinerators to help overcome local opposition.
One way to decrease the cost of incineration and to eliminate community opposition is to burn the wastes on a ship at sea. Because these ships do not use scrubbers to clean the flue gases, they can burn wastes for as little as $80 per ton. Scrubbers are not needed, says Max Halebsky of Global Marine Development Inc., Newport Beach, California, because halogens, trace metals, and other contaminants in the flue gases end up in the ocean, where they are greatly diluted.
Furthermore, many of these materials, which would be pollutants if they were emitted from a land-based incinerator, are natural constituents of the ocean; the amount added to the ocean from the burning of wastes is insignificant compared to their normal concentrations.
There are now two functioning incinerator ships: the Vulcanus, operated by Ocean Combustion Service By, a Dutch subsidiary of the Hansa Shipping Line of Bremen, West Germsny,. and the Matthias II,. operated by Industries Anlage of West Berlin. The Matthias II can handle 1100 cubic meters and the Vulcanus 3500 cubic meters of waste per sailing. About 4 years ago, the Vulcanus sailed into the Gulf of Mexico to incinerate chlorinated hydrocarbons generated by Shell Chemical Company. EPA monitored that burning closely and was so satisfied with the results that, in 1977, it gave the U.S. Air Force permission to have the Vulcanus burn more than 10,000 tons of surplus Agent Orange, a toxic herbicide contaminated with even more hazardous dioxins.
The herbicide was incinerated west of the Johnston Atoll in the mid-Pacific. EPA also monitored that test and found that destruction of the wastes was essentially complete and that no hazardous byproducts were released into the environment.
Since Agent Orange and dioxins are among the most difficult wastes to dispose of completely, the success of the test would seem to indicate a bright future for ocean incineration. In fact the Vulcanus already has contracts for more work in this country and Global Marine is investigating the possibility of refitting a surplus tanker as an incinerator ship with a capacity of 12,000 tons.
Last month Ocean Combustion announced that it would construct a new incinerator ship to serve the North American market exclusively. Some observers even speculate that increased use of ocean incineration might eliminate the need for construction of new large land-based incinerators. Proponents of land-based incinerators point out, though, that increased use of incinerator ships will require construction of hazardous waste storage areas at selected seaports, and this may be frowned on by port authorities.
Incineration on land might have a brighter future, however, if emissions could be controlled by a technique less expensive than scrubbing, which generally involves contacting the flue gas with an alkaline material to remove and neutralize acidic halogen compounds. Because of the high temperatures required for complete combustion, this exhaust is very corrosive, so expensive materials must be used in construction of the scrubber. Disposal of the neutralized salts also increases the cost of the operation. One potential way to reduce the cost is to find a use for the material removed from the flue gas.
EPA and several American research groups participated in a study conducted by the Canadian government in which chlorinated hydrocarbons were used as a boiler fuel in the manufacture of cement, which requires a very large energy input. In the test, as much as 20 percent of the boiler fuel could be replaced with PCB's, pesticides, and other similar materials while maintaining complete combustion. Even more important than the fuel savings, though, is the fact that halogens liberated during combustion become a permanent part of the cement matrix. In fact, chloride salts must frequently be added to cement during its manufacture, so the wastes replace a valuable raw material.
Despite the fact that this process seems an ideal way to dispose of halogenerated hydrocarbons, it has not been used since the test, according to Fred Lindsey of EPA. One cement manufacturer was interested in the process, he says, but wanted the government to indemnify the company against all potential risks. Another company, in Detroit, was eager to adopt the technology but was prevented from doing so by local opposition. Consequently, Lindsey says, a proved, potentially money-saving technology lingers on the shelf.
Another alternative would make it easier to control emissions by reducing the temperature of combustion. Barry Hertzler and his colleagues at the Lockheed Research Center in Palo Alto have developed a prototype unit that uses microwaves to incinerate wastes. Their 15,000-watt furnace can handle as much as 7 kilograms of material per hour. The wastes are mixed with oxygen and passed into the reactor, where they are ionized into a plasma. The gas itself has a temperature of only about 450ºC, but free electrons in the plasma, Hertzler says, have a destructive energy that is equivalent to incineration at 16,000ºC.
The net result is that the waste is completely consumed, but with less expenditure of energy than is required for conventional incineration and without formation of the corrosive atmosphere that would degrade both the containment vessel and the scrubber. The microwave furnace can thus be much smaller than the conventional high-temperature incinerator, and can even be made portable. Hertzler and his colleagues are now constructing a unit that will handle three to six times as much material as the prototype. Much more work will be needed, however, before the cost of the process is reduced to that of conventional incineration.
Another alternative, under study by S. J. Yosim and his associates at Rockwell International, Canoga Park, California, is incineration of hazardous wastes in beds of molten sodium carbonate.
In this process, waste and air are continually introduced under the surface of the melt, which is kept at a temperature of 800º to 1000ºC. The intimate contact of the air and waste with the hot salt produces immediate and complete combusion, Yosim says. Acidic byproducts, such as hydrogen chloride and sulfur dioxide, are instantly absorbed and neutralized by the alkaline sodium carbonate, so that the only gaseous products emitted are water and carbon dioxide. The process has been studied on a variety of hazardous organic wastes and even on some low-level radioactive wastes. In general, Yosim says, the extent of destruction is greater than 99.99 percent and no radioactivity or organic compounds are detected in the effluent gas. The process is still at an experimental stage, however, and promises to be quite expensive unless major improvements can be achieved.
The controversy about the potential for air pollution arising from incineration is minor compared to that surrounding the injection of hazardous wastes into deep wells. Proponents of deep-well injection consider it to be one of the safest and cheapest ways to dispose of hazardous wastes; opponents have called it everything from shortsighted to criminal. Not surprisingly, the truth appears to lie somewhere near the middle.
Deep-well injection involves pumping wastes into porous sandstone and limestone formations 1000 to 3000 meters below the earth's surface, where they become permanently stored. The technique has been in use for disposal of brine in oilfields since the mid-1920's and for disposal of hazardous wastes since the early 1950's. There are now about 70,000 wells for brine disposal and about 300 that are used for other types of wastes. The majority of both types of wells are concentrated in Texas, Louisiana, and other oil-producing states, but some are scattered through such disparate states as Colorado, Illinois, Ohio, and Michigan. According to Ray W. Amstutz of Williams Brothers Engineering Company in Tulsa, suitable sedimentary formations for deep-well disposal are found under about half the land area of the United States and ideal conditions are found under about a quarter of it.
Most of the 300 waste wells now in operation are owned by companies that use them for their own wastes. but perhaps a dozen are owned by waste disposal companies, such as Rollins and Browning-Ferris Industries, that use them for commercial disposal services. Proponents argue that deep-well infection is a very safe and inexpensive technique. All of the injection sites, Amstutz says, already contain brine that has been separated from freshwater zones for millions of years by so-called aquacludes, layers of impervious shale that maintain the isolation. As long as care is taken in the construction of the wells themselves, he argues, there is no reason why injection of wastes should change the situation. And if a use should ever be found for the wastes, he adds, they can be pumped back to the surface.
Once the well is drilled, furthermore, the cost of operation is almost negligible. In some cases, pumping of the wastes is not even required: negative pressure in the wells sucks the wastes into the depths. The overall cost of disposal in wells is thus on the order of 8 to 14 cents per gallon of liquid wastes, exclusive of transportation costs. This low cost makes their use very attractive.
Critics, however, argue that the lack of precise knowledge about the fate of the injected wastes is very unsettling. David Axelrod of the New York State Health Department, for example, argues that the thought of carcinogens, mutagens, and other potent chemicals wandering around below the earth's surface is profoundly disturbing. Critics within the industry, who prefer to remain anonymous, echo this argument. Amstutz and others, though, argue that general liquid movement within the formations is typically measured in inches per year, so migration is negligible.
Critics also cite such incidents as the earthquakes in the Denver area that were apparently triggered by injection of wastes into wells at the Rocky Mountain Arsenal and the 1968 eruption of an overpressurized waste-injection well in Erie, Pennsylvania, as examples of the hazard potential of this technique. Defenders argue that the Erie well was poorly engineered and that the wastes in Colorado were not injected into sandstone formations, but rather into fractures in granitic rock. Proponents concede that there have been some cases where faulty construction of wells has resulted in contamination of groundwater, but they argue the new construction techniques and new regulations minimize such occurrences.
Deep-well injection is now permitted in only about 20 states. Typically, Amstutz says, states that have substantial experience in regulation of oil wells are the ones that permit deep-well disposal. Regulations in those states prohibit injection of wastes into zones that are above or near drinking water supplies or into zones that might have some future use such as a source of geothermal energy or natural resources. They also set standards for the construction of well casings and the
EPA is planning to propose regulations soon that will buttress the state regulations and that will, in general, require more monitoring to detect potential leakage of contaminants. EPA has been specifically directed by Congress, however, to be very flexible in its regulations about deep-well injection, and the forthcoming regulations will probably not be an impediment to the industry's growth. Industry sources now estimate that from 3 to 5 percent of hazardous wastes are disposed of in deep wells, but that the total should increase substantially as the number of new wells grows by about 20 per year. Despite the reservations of critics, therefore, it would appear that deep-well injection is going to have an ever-increasing share of the waste disposal market .— Thomas H. Maugh II
BURIAL IS LAST RESORT FOR HAZARDOUS WASTES
Despite the many alternatives available for disposal of hazardous wastes, there are a great many materials that are too low in value to recycle, too difficult to degrade, too thick to inject into deep wells, and too contaminated with heavy metals and other non-flammable materials to incinerate.
Some investigators consider these disposal methods to be volume reduction techniques because they leave a residue of hazardous materials. For most of these materials, the disposal option of last resort is burial in the ground. It's not the ideal solution, it's not necessarily even a good solution, but, realistically it's the only solution we now have. The problem then is to regulate landfills in such a manner that potential problems created by escape of toxic materials are minimized.
The Environmental Protection Agency (EPA) has sponsored much research on the various facets of landfilling, such as enginering techniques, liners, covers, and gas generation. But if privately sponsored research is included, the greatest amount of effort has been devoted to the chemical solidification of wastes — the development of techniques to bind the wastes into a coherent mass before burial so that leaching of toxic materials by groundwater is minimized.Solidification is now used for only a very small percentage of hazardous wastes, but it promises to be one of the most important disposal techniques of the future. It also promises to be one of the most complex to evaluate. A recent survey by Robert B. Pojasek of Energy Resources Company Inc. of Cambridge found that at least 41 different companies and research groups have developed proprietary processes for the solidification of wastes.
Most of the processes for hazardous wastes are outgrowths of processes for solidification of low-level radioactive wastes; some processes, in fact, appear to be suitable for both. They can be broken down into four major categories: cement-based techniques; pozzolanic, or lime-based techniques; thermoplastic binders; and organic binders.
The cement-based or cementitious techniques are most common because they are generally the cheapest and easiest to use. They are effective primarily for inorganic wastes, and are particularly advantageous for wastes containing heavy metal ions. The high pH of the cement mixture tends to keep the metal ions in the form of insoluble hydroxide salts not unlike those found in the ores from which the metals were, originally obtained. Many of the materials commonly present in wastes, such as asbestos, latex, metal filings, and plastic further strengthen the cement matrix, and proprietary additives are frequently used to further tie up troublesome contaminants. Organic materials in the wastes, however, generally weaken the cement.
Two of the better known cementitious processes are the Sealosafe process developed by Stablex Corporation, whose U.S. headquarters are in Radnor, Pennsylvania, and the Chemfix process, marketed by Chemfix Inc. of Kenner, Louisiana. Stabler operates two landfills in the English Midlands and one near London at which metal finishing and plating wastes from the automobile industry and some other materials are solidified before burial. The company hopes to open a 500,000-ton-per-year landfill in Groveland Township, northwest of Detroit, for disposal of wastes from automotive, chemical, and plating plants, but state and local officials are resisting because of fears that toxic substances might be leached from the solidified mass. Stablex says the cost of solidification by the Sealosafe process can vary from $5 to $500 per ton, depending on the nature of the waste.
The Chemfix process, in contrast, is most often used at the waste generator's facility for onsite fixation of sludge. A mixing unit and the additives are contained in a trailer that is driven to the plant. Sludges are pumped from holding lagoons, mixed with additives, and deposited in another holding lagoon or directly in a landfill and allowed to harden. In the first 7 years of commercial use of the process, the company says, more than 100 million gallons of wastes have been treated, including materials from the petrochemical, steel, electronics, and electric utility industries. The average cost of treatment is 3 to 4 cents per gallon.
The advantages and shortcomings of the cementitious techniques, like those of the other techniques, have been amply demonstrated in the nuclear waste industry, according to Douglas W. Thompson, Phillip G. Malone, and Larry W. Jones of the U.S. Army Engineer Waterways Experiment Station in Vicksburg, Mississippi, who have performed tests on many of the commercial processes. A major advantage is that wastes do not have to be dried before processing. The principal shortcoming is that low-strength cement-waste mixtures are often vulnerable to acidic leaching solutions. Other shortcomings include the need for expensive additives to treat many types of wastes and the added weight and bulk contributed by the cement.
The cementitious solidified mass, like the products of other types of processes, is also vulnerable to freeze-thaw and wet-dry cycles in the environment. This should not be a problem, however, if the material is buried below the frost line.
The term "pozzolanic" comes from Pozzuoli, a city near Naples where volcanic silico-aluminate calcium ash has been mined since before the time of Christ. When mixed with lime and water, the ash forms a very hard material known as pozzolanic concrete. The most common materials used in place of the ash today are fly ash from electric power plants and cement kiln dust, which are themselves wastes. Proprietary additives are also used with the mixture to enhance strength and to limit the migration of contaminants.
As is the case for the cementitious processes, the additives for the pozzolanic processes are generally inexpensive and widely available, the equipment required for mixing is simple to operate, and the chemistry is relatively well known. The major shortcomings, Thompson says, are the increased weight and bulk, vulnerability to acidic leaching solutions, and difficulties associated with organic materials in the sludges.
The principal application of pozzolanic processes may be solidification of the sludges produced in removal of sulfur oxides from the exhaust gases of coal-fired power plants. Two companies that have processes for treatment of such wastes are Dravo Lime Company of Pittsburgh and IU Conversion Systems Inc. of Horsham, Pennsylvania. Dravo markets an additive called Calcilox that, when added to flue gas sludges, produces physically stable materials with the consistency of consolidated soils. The additive itself costs about $40 per ton, but its use with flue gas sludge, the company says, costs only about 40 cents per ton of coal burned. IU markets a process, called Poz-OTec, that converts flue gas sludge into a stable material that can be used in properly designed landfills, embankments, roads, parking lots, and the like. IU already has contracts with power plants that produce more than 22 million tons of sludge per year. Even so, such processes are still used for only a small portion of all flue gas sludges, since there are now no regulations requiring that they be stabilized.
Thermoplastic techniques use materials such as bitumen, asphalt, paraffin, and polyethylene that soften when heated, bind tightly to wastes, and solidify when cooled. Wastes must be dried before they are mixed with the hot thermoplastic material, and the resultant solid must frequently be placed in a steel drum or other container for structural support. These processes generally require relatively expensive equipment for heating and mixing the waste and the thermoplastic material; they also require skilled operators. Furthermore, since the binder accounts for one-third to one-half of the bulk of the finished product, the process is somewhat expensive.
A typical thermoplastic process is the volume reduction and solidification (VRS) process developed by the Werner & Pfleiderer Corporation of Waldwick, New Jersey. In the process, asphalt (or a similar binder) and wastes are passed through a specially designed heated screw extruder that mixes the two components thoroughly, then releases them into containers or a storage area for cooling. The VRS system, the company says,has been successfully tested in more than 2,000 different applications in the chemical, plastics, food, and nuclear industries.
The principal advantage of the thermoplastic techniques is that the binders adhere exceptionally well to the incorporated wastes and are resistant to most aqueous solutions. The migration rates of contaminants are thus generally lower with thermoplastic processes than with any other technique. Among the shortcomings, Thompson says, are the flammability of thermoplastic materials, the need for great care in processing wastes that are volatile at low temperatures,and the slow deterioration of the product that may be caused by organic solvents and some other organic materials. Thermoplastics thus seem to have promise primarily for extremely hazardous wastes, concentrated wastes, and radicactive wastes, where leaching or migration of the materials must be held to the absolute minimum.
The final class of processes involves organic polymers. In these processes, a small amount of monomer is mixed thoroughly with the wastes and a catalyst is added. As the polymer forms, typically, it does not combine chemically with the water, but forms a spongelike mass that traps solid particles while permitting much of the water to escape. The most common polymer technique is the urea-formaldehyde process, which was developed by the Teledyne Corporation of Louisville. Solidification with polyester resins has been studied by R. V. Subramanian and R. Mahalingam of Washington State University, and polyvinyl chloride has been studiedby investigators at the Dow Chemical Company.
The primary advantages of the organic polymer techniques are that only small quantities of additives are required to solidify the wastes (often as low as 3 percent of the total weight), the techniques can be applied to either wet or dry sludges, and the finished waste-polymer mixture has a low density compared to the products of other solidification techniques. But if not enough resin is used, says Thompson, the polymer matrix does not trap all the wastes. The catalysts used in the urea-formaldehyde process, moreover, are strongly acidic; precipitated metal ions thus may redissolve and escape in water not trapped in the polymer matrix. Some organic polymers are biodegradable, and both urea-formaldehyde and ployesters are unstable in corrosive environments. Furthermore, the final product must generally be placed in a container before disposal.
Many of these problems can be overcome with a system developed by Hyman R. Lubowitz and his colleagues at TRW Systems in Redondo Beach, California. According to Robert Landreth of EPA, this system produces solids that show the least amount of leaching of any produced by other systems. Lubowitz uses polybutadiene as a binder to form wastes into cubes about 0.67 meter on edge. He then fuses onto the entire surface of the cube a layer of thermoplastic high-density polyethylene (HDPE) about 1 to 2 centimeters thick. HDPE is used to protect underground electrical cables and other equipment and has exceptional resistance to deterioration. Because the HDPE is fused onto the surface of the wastes with no seams, furthermore, it can withstand a great deal of stress, so that no other container is needed.
Lubowitz is also investigating a system for disposing of drums of chemicals — such as those that have been abandoned at various sites — in such a manner that they would not have to be opened and analyzed. The drums would be placed in a fiberglass cocoon big enough to accommodate warped or dented drums. A layer of HDPE would then be fused onto the surface. Tests at TRW have shown that such cocoons can withstand much more compression and stress than would be encountered in a disposal site and that they completely prevent leaching of the barrel's contents.
The principal disadvantages of the TRW system are the need for sophisticated and expensive equipment for the encapsulation process, and the cost. Lubowitz estimates that operation of a full-scale plant would cost about $91 per ton of dry waste; about 50 percent of that cost represents the purchase price of the resin, however, and Lubowitz thinks it should be possible to use a much less expensive grade of resin than that with which the experiments were conducted.
In general, say both Landreth and Thompson, solidification is a very good technique if it is used with proper constraints. The major problem with many of the processes is that they simply have not received enough testing under actual conditions in the field to determine their long-term resistance to deterioration and leaching, but such tests are now beginning at several locations.
What has become clear so far, says Landreth, is that each process works on a different spectrum of materials. No company has a process that can handle everything, he says, but at least one process can be selected and tailored to handle anything. And if the solidified material is disposed of in a secure chemical landfill, then there should be virtually no problem with leaching.
The problem then is to make the landfill secure. Landfill has long been the most common method for disposal of hazardous wastes because it has been inexpensive. Burial in a conventional sanitary landfill — which differs from a secured chemical landfill primarily in the degree of protection against leaching — costs between $3 and $8 per ton. Burial in an unsecured chemical landfill may have cost twice that much before the Resource Conservation and Recovery Act (RCRA) was passed. The costs were low because the technology was simple. Typically, a hole was dug in clay at a selected site, unconsolidated sludge and drums of chemicals were placed in it, and the hole was filled and covered with clay to keen out rain and other water. There are probably less than 30 commercial chemical landfills in operation around the country, but there is a large, unknown number of landfills at individual plant sites and probably tens of thousands that have already been closed. The vast majority of these are safe now and are likely to remain so in the future. The problem is the small number of sites that have inherent defects in construction or that are disturbed by man after their completion.
New regulations proposed by EPA under the provisions of RCRA are designed, in part, to assure safer construction of landfills. They would set specific standards for construction and operation of the site; they also would discourage use of landfills for liquid wastes, and would ban their use for certain volatile and flammable materials. More important, they would require monitoring of the completed landfill for an extended period to demonstrate that the site is sealed, and would establish standards for financial liability for the site's owner and operator for any incident resulting from the escape of the buried chemicals. Those regulations are not yet in force, but a good example of the type of operation that can be expected under them is the new landfill (illustrated in the accompanying photograph) operated at Model City, New York, 'by SCA Chemical Waste Services Inc. SCA's Peter Dunlap says this is the world's largest secured chemical landfill.
The landfill cell, 150 meters long and 150 meters wide, is excavated in dense clay and fitted with a liner of impervious, reinforced synthetics, which is then covered with a layer of about 1 meter of clay. Associated with the liner is a leachate collection system so that, in the rare event that water should enter the landfill, it could be pumped out and treated. The main landfill cell is divided by clay barriers into a number of subcells for specific types of hazardous wastes. Drums of PCB's and other chlorinated hydrocarbons might be kept in one subcell for example, precipitated metal hydroxides in another, and organic sludges in a third. In this fashion, incompatible wastes are kept separated and the location of specific materials is known in case there should ever be a need to retrieve them. When it is filled with wastes, in about 12 to 18 months, the pit will be capped with another synthetic liner and a layer of clay, and another pit opened nearby.
SCA has six smaller landfills at the site that have already been closed. Surrounding and interspersed among them is a network of nearly 120 wells. Water from these is analyzed at regular intervals to ensure that there is no leakage from any of the sites. In accordance with the proposed EPA regulations, that monitoring is scheduled to be continued for at least 20 years after the last landfill at the site is closed. EPA's presumption is that if no leakage is detected during the operating life of the plant and for 20 years thereafter, the probability of a leak is small.
Several other companies operate similar landfills throughout the country, particularly in Texas, California, and Alabama. SCA itself has two smaller facilities at other sites and operated a third, the Earthline landfill at Wilsonville, Illinois, until it was shut down by a court order last year.
The shut down illustrates one of the major problems facing operators of landfills: citizen resistance. The court order closing Earthline was issued at the request of local citizen's groups who opposed the landfill; it was granted despite assurance to the court from both the federal EPA and the Illinois EPA that Earthline was necessary for disposal of wastes in that region, that it was operated responsibly, and that it posed no hazard to the community. That decision is being appealed to a higher court, but meanwhile, wastes that had been destined for Earthline are undoubtedly being buried in less secure facilities.
Dunlap contends that EPA should have presented a much more forceful argument to the court in favor of the landfill remaining open, and that it should take a much more active role in siting of future facilities. This view is echoed by some individuals within EPA and in the environmental community. Leslie Dachs of the Environmental Defense Fund, for example, concedes that a certain number of secure landfills will be required in the foreseeable future. He says that these should be organized on a regional basis and argues that EPA should take an active role to ensure that the best possible sites are chosen.
EPA appears to be moving in that direction. One study now in progress for EPA is an analysis of the many cases in which permission to construct a landfill has been denied by courts and other agencies. If it can be determined what factors were most important in those decisions, EPA could be better prepared in future cases. EPA is also enlisting the help of such groups as the American Public Health Association, the Isaac Walton League, the League of Women Voters, the Environmental Action Foundation, the National Wildlife Federation, and the Technical Information Project to present programs of reassurance in communities where landfills might be located. It may also encourage state legislators to preempt local ordinances that might impede construction of landfills at appropriate sites.
The construction of SCA's Model City landfill cells has, in fact, been delayed by such ordinances. Ultimately, the New York State Supreme Court ruled that the state's Department of Environmental Conservation (DEC), which authorized the facility, has the power to preempt local laws. The court did, however, stipulate that SCA post a $100,000 bond to assure that the site would be restored to its natural condition if DEC did not issue an operating permit for the largest cell after its construction.
EPA's proposed regulations would, in effect, require posting of a much larger bond for all landfills. The proposals would require that anyone who operates a chemical landfill make a cash deposit large enough to guarantee that the site will be properly closed and monitored for 20 years.
The rules would also require $5 million in insurance coverage for each site, half for "sudden and accidental occurrences" and half for "non-sudden and non-accidental occurrences." This could be provided by a commercial policy or, more likely, through self-insurance.
If this regulation is enacted, industry sources argue, the cost will be enormous and it may very well doom the concept of onsite disposal of wastes. One example frequently cited by opponents of the proposal is the Du Pont Company, which has about 88 plants in the United States.
Assuming that the company disposes of hazardous wastes at only half of those sites, it would have to establish that it is self-insured for $220 million. This amount represents some 4.6 percent of the company's total equity, and such self-insurance would be very difficult for the company to achieve. "If Du Pont doesn't have the resources to comply" with the proposed regulations, asks David Carroll of the Manufacturing Chemists Association, "how can anyone?"
As is so often the case, then, EPA is caught between a rock and a hard place — it must regulate the disposal of hazardous wastes, but it must do so without closing down American industry. The agency is now reviewing responses to its proposed RCRA regulations and may, in fact, modify some of them to make them a little more flexible. But no matter what changes are made, it seems clear that many small companies will be closing down their own disposal operations and shipping their wastes to commercial disposal firms. It is not clear what effect this will have on the chemical and allied industries, but the waste disposal industry, it would seem, should be prepared for a magnificent boom..