Health Center, has been submitted to the committee for review. The developments reported are encouraging and indicate that industry is going steadily ahead with the technical tasks directed toward the reduction of wastes reaching our water resources. -4s now developing, a large portion of the technical work of the committee is being performed by work groups composed of the best technical talent from those industries sending representatives to the committee. It is anticipated that by bringing together industries which have what might be termed a community of interest in so far as wastes are concerned. duplication of effort and needless expense can be minimized. Likewise, those groups best equipped and staffed to conduct studies along certain lines can advantageously be assigned those tasks. The exchange of data and information of a fundamental nature-information which can be applied by the participating industries to their individual problems--udl continue to be encouraged as more groups take part in the activities. These activities will not in any way conflict with or replace activities that already have been sponsored, organized, and financed by various industries. On the contrary, the thought is t o extend the base of technical investigation and broaden the understanding of the potentialities of stream improvement in terms mutually agreeable to both industry and government. As a typical and fundamental problem, for which there is pressing need for suitable definition, the question of “yardsticks” of pollution for all water uses is a good example. This is a technical problem which in one way or another affects all industries discharging wastes into natural water sources. It is an example of
but one of the many technical tasks which require wide consultation and general agreement. The answer appears to lie in close working relations, in teamwork. SUMMARY
I n summary, the need for conserving the quality of our water resources to take care of various uses, including industrial water supply, is emphasized. Municipalities, industries, and others have their part in the solution of water-pollution problems. Even though considerable progress is being made, much remains to be accomplished. Cooperation of all concerned is advocated in proceeding with tasks ahead in reducing water pollution. Such procedure, in developing essential technical information on waste utilization or treatment and improvement in water quality, is illustrated by the organization and activities of the National Technical Task Committee on Industrial Wastes. Developments in this program of industry and government already are indicative of progrqss to be expected in taking care of technical aspects of the improvement of the waters of the nation. LITERATURE CITED
(1) Conservation Foundation and National Association of hlanu-
facturers, “Water in Industry,” December 1950. (2) Workman, R. W., “Shame of Our Streams,” State Water Commission of West Virginia, p. 15; reprint from Charleston ( W . Vu.) Gazette, November 1951. (3) Ibid., p. 16.
RECEIVED for review April 10, 1963.
ACCEPTED
October 9, 1953.
Disposal of Atomic Energy T h e special nature and products of the atomic energy industry present some important environmental problems, especially as related to disposal of radioactive and toxic wastes. Research and development on which to resolve these problems are being carried out under Atomic Energy Commission contracts uTith public agencies, universities, national laboratories, and private research organizations. The paper discusses these problems, the progress made to date in resolving them, and the policy of the Atomic Energy Commission in dealing realistically with questions of waste disposal w-hich have plagued many other industries.
ARTHUR E. CORMAN Disision of Engineering, C‘. S . A t o m i c Energy C o m m i s s i o n , W a s h i n g t o n , D . C .
NDUSTRIAL management in the United States has come t o appreciate that a liberal farsighted policy in waste disposal and environmental sanitation has many advantages over the oldfashioned “do as you please” attitude that once was commonplace. Management of most industries which followed this policy now realize it was shortsighted and a mistake, and their numbers are fast diminishing. I n contrast, today we find specialists such as medical directors, industrial hygienists, sanitary engineers, chemists, and biologists in industry working together conducting important research in waste disposal. These scientists hold important committee memberships in professional societies which are leading the way to a newer and mutually profitable relationship between industry and public agencies responsi-
2672
ble for the health, safety, and xelfare of our people and protection of our natural resources. The purpose of this paper is to point out some of the environmental sanitation problems of the atomic energy industry, and to record how they are being worked on both within and outside the industry and with the cooperation of public agencies, universities, and other industries. RAPID GROWTH QF ATOMIC ENERGY IIVDUSTRY
The atomic energy industry with its unprecedented expansion program is in fact a late comer in a nationally well integrated industrial, economic, and social community. This in addition to the uniqueness of its operations and its product, the lack of general
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Industrial Process Water knowledge of the industry’s technology and terms, the secrecy which necessarily must be maintained, and the fact t h a t b y act of Congress the industry is under government control, places a more than ordinary responsibility on sponsors of the industry. It is no simple task for a new industry to compress in a few years research and development that would normally take decades. B u t i t is being done in the atomic energy industry. The effort of Atomic Energy Commission in environmental sanitation is to prevent, for this industry and the public, many of the headaches which others have experienced and t o do this without blocking progress while the industry is developing at an unprecedented rate.
.,
*
4
1
COOPERATION WITH OUTSIDE AGENCIES
The Atomic Energy Commission has elected to evaluate and to seek solutions of its problems by enlisting the aid of experienced, well established federal agencies which for many decades have been working on similar problems with other industries. I n particular, these agencies are the Geological Survey, the Weather Bureau, the Public Health Service, the Corps of Engineers, and the Bureau of Mines. Specialists from these agencies are working on specific problems and in many areas. At the same time they are being indoctrinated in the various facets of the atomic energy industry. In turn, the staff of the Atomic Energy Commission and its contractors are benefiting by the advice, experience, and continuing interest of these agencies. Much of the work is being done under contract with the Atomic Energy Commission. In some cases, however, the cooperating agencies have assigned technicians for service with the Atomic Energy Commission or its contractors without reimbursement. Research and development contracts in sanitary engineering have been placed at a number of universities, private research institutions, and national laboratories serving the industry. The universities now working on such contracts include California, Harvard, Illinois, Johns Hopkins, New York, Texas, and the Massachusetts Institute of Technology. The staff of the commission follows the practice of conferring with state officials having responsibility for preventing pollution of the atmosphere, ground, and surface waters in the disposal of wastes from industry. In several areas advisory committees have been organized on which federal, state, and local officials are represented. Usually the members of the committee are invited to visit Atomic Energy Commission production or research areas, where they are informed as t o processes and wastedisposal methods and are asked to submit criticisms and suggestions. Such advisory committees are in existence in relation to activities at the Hanford and Savannah River Works and at the Knolls Atomic Power Laboratory near Schenectady, and one is under development for the National Reactor Testing Station in Idaho. Visits t o the Argonne, Oak Ridge, and Brookhaven National Laboratories have been made by representatives of the Illinois, Tennessee, and New York State Departments of Health. A few weeks ago the writer met with the Ohio River Valley Water Sanitation Commission and gave information concerning nine major Atomic Energy Commission projects in t h a t valley. This meeting was supplemented by a visit during the week of February 22 t o five of these plants by three security-cleared representatives of the Ohio River Valley Commission. SITE SELECTION
Many situations in the atomic energy industry present environmental problems. Those of special interest and concern to sanitary engineers include, first, considerations related t o the selection of a plant site. The sanitary engineer is especially concerned with: t h e availability of adequate water supply of suitable quality, whether it be from surface or ground sources, the degree to which water uses, current or future, may affect the prior rights of others, the suitability of the soils or nearby waterways for stor-
December 1953
age or disposal of waste products, and the dilution factors in nature which may be used in establishing levels of waste treatment which must be given t o solid, liquid, and gaseous wastes before they may be released to the ground, surface waterways, or the air. WATER SUPPLY
A firm source of water supply is a basic requirement for most industries. The atomic energy industry is no exception. Prodigious amounts of water are used for cooling purposes, especially in removing heat generated in reactors where Essionable material is irradiated. The degree of purification required depends on whether or not the water is subsequently to be exposed to irradiation by neutrons. In flow-through type reactors, such as those used for cooling the units a t the Hanford Works, very large modern plants for water treatment and filtration are provided, in order that the cooling water may contain a minimum of dissolved and suspended matter which would be irradiated while flowing through the reactor. Such water is returned t o the Columbia River after a period of detention has permitted decay of much of its induced short-half-life radioactivity. Where a reactor is cooled by water in a closed system, an even higher degree of purification of this water is carried out to lessen irradiation and to protect the system. Such water is usually demineralized. In this case, the heat taken up in the reactor is removed from the reactor system by a secondary heat exchanger and finally by recirculation over a cooling tower. Water used in the secondary system heat exchanger requires a lesser degree of treatment than water t h a t flows directly through the reactor. Some natural waters may be usable for such purposes with no treatment. Large amounts of water are $so used in heat exchangers for gaseous diffusion plants. The control over water used in them systems is a most important responsibility in operation. DISPOSAL OF WASTES
Low LEVELWASTES. By far the largest volumes of wastes from this industry are low in radioactivity and toxicity (4). It is the practice to hold and to monitor liquid wastes of this sort before they are released t o the ground, t o waterways, or to public sewers, in order t o be certain t h a t their levels of activity are within prescribed limits of safety. Wastes produced in substantial volumes &nd those whose levels of activity exceed safe limits present a real problem both in treatment and cost. Typical of such wastes are effluents from laundries handling garments contaminated by radioactive material, drainage from laboratory sinks in research areas where radioactive isotopes are used, wash water from various decontamination processes, and water used in basins to shield operators from radioactive materials being stored or worked on. Because the aftereffects of release of these wastes to nature and their ultimate effects on people and property are not too well understood, a conservative policy has been adopted as to the degree of decontamination required. Evaporation and ion exchange, which are the principal methods now used in treating high-level wastes, have often been used for low-level wastes. In the interest of economy, research is seeking to find better and inexpensive methods of treating large volumes of low-level wastes, and t o evaluate the subsequent dilution factors in nature which may be taken advantage of and thus reduce the degree of treatment required. Other industries make use of these dilution factors in nature. The indexes for evaluating them in relation to many industrial wastes are reasonably well understood by pkblic officials having responsibility for protecting the public health and our national resources. Generally, this is not the case in dealing with radioactive wastes, although as research proceeds some of the needed parameters are being established and recognized. The possibility of using biological methods such as those used
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by sanitary engineers in treating domestic sewage and industrial wastes is being studied at several universities ( 4 ) under contract with the Atomic Energy Commission. At New York University the feasibility of using the trickling filter process for decontaminating laundry wastes a t the Knolls Atomic Power Laboratory is being investigated; the activated sludge process as a means of removing radioactivity from waste streams is under study a t the University of California; the effect of radioactivity on anaerobic digestion of seR-age sludges is the subject of research a t the University of Illinois; and a t the University of Texas studies are under way to determine the extent to which algae in streams or ponds could be used to take up radioactivity in low-level wastes. The long half life of certain radioactive materials makes it essential to appraise the effect and probable ultimate fate of viastes from this industry before they are released in any significant quantities into the ground, air, surface waterways, or sea. The importance of this time factor constitutes a significant difference between wastes of the atomic energy and those of most other industries, Chemical, biological, and bacterial contaminants when released are subject to substantial changes in nature usually in hours or days, depending on the environment to which they are exposed, Ordinarily, with time and subsequent dilution these contaminants become progressively less obnoxious or hazardous, depending on their origin. On the other hand, a radioactive waste is definitely tagged as to the period it will emit radioactivity. In the case of long-lived elements the prolonged period of hazard from radioactivity places on one who disposes of such \Tastes a responsibility which cannot be dealt with lightly. The fact that many inert materials and living things in nature take up and hold radioactivity is a most important factor in evaluating the capacity and limitation of various methods of disposal of low-level liquid wastes. The phenomenon is exceedingly important and needs to be better understood. To a considerable degree disposal on or into the ground through surface leaching pits, lagoons, cribs, or.reverse wells must be governed by the capacity of the soils to take up radioactivity prior to passage of the liquids downward to the water table. The Geological Survey (16) is obtaining specimens of soils from all major Atomic Energy Commission areas of operations and a t many other places in this country for the purpose of classifying the capacities and limitations of these soils in taking up radioactivity. Further studies are being conducted a t Yale University and a t Atomic Energy Commission National Laboratories (10). The objective is to learn more about these soils, especially their physical structure and properties, which may account for ability to remove and perhaps fix radioactivity from water and waste streams. Resolving this problem will call for much teamwork on the part of the geologist, the mineralogist, the physical chemist, and the nuclear physicist and chemist. Once this phenomenon and its limitations are understood, the method can be applied in many water-decontamination and wastedisposal problems. The direction and rate of movement of ground waters toward sources of downstream water supply must be given careful consideration. The degree of dilution of a contaminant released from a point source of discharge is governed by the characteristics of ground water flow. Where this flow is laminar, as is usually the case in ground water flow, the amount of dilution may not be great. The contaminant may move in a ribbonlike manner, expanding somewhat as it migrates. This fact must be taken into consideration u hen moliitoiing 0-ells are used in evaluating the effectiveness of a waste disposal procedure. Failure to obtain evidence of contamination is no assurance that it does not exist or that the method of disposal followed has been effective. In the absence of good information as to the geology of the area and the characteristics of the subsoils in retaining radioactivity, negative results could be misleading, Where rate of flow of ground water is slow, often time is available for substantial radioactive decay of short-half-life contaminants.
An important consideration when radioactive liquid wastes are discharged to surface waters is the ability of inert suspended matter and organisms in the water and a t the stream bed to take up radioactivity. Often when the contaminant is radioactive, the orthodox methods of stream surveying may not be adequate to evaluate the effects of organic pollution. In this case the B.O.D. of the stream is of much less importance than the sediment loading, the characteristics of the sediments, and the conditions under which they are deposited and resuspended. Knowledge as t o the sediments transported by a stream, its cross section, velocity, and flow characteristics is particularly important in evaluating the dilution or concentration factors of a stream or river. HIGHLEVELWASTES. The volume of wastes from atomic energy operations which are high in radioactivity are relatively small in comparison with low-level wastes. The quantities are substantial, however, and constitute a problem from the standpoint of potential environmental hazards, cost of treatment, and/or storage. Sometimes such wastes may be processed and stored under conditions m-hich have parallels in other industries. Usually, however, the methods and facilities employed must be surrounded by extraordinary precautions and special materials must be used. This all adds substantially t o the cost. The value of the product as well as its hazardous properties has a direct relationship to the investment which can be made in a facility to store, treat, and dispose of a radioactive or toxic waste. But, regardless of value, the cost of treatment to render the waste harmless is a proper charge against the industry and must eventually be reflected in the cost of the product. The solution of the cost problem lies in research and development and not in cutting corners and exposing the industry to criticism and others to hazards. I n some industries, as a result of research, profits have been made from waste products, but this is the exception rather than the rule. B capricious attitude by industry in the disposal of long lived radioactive wastes could seriously affect the national resources and could be harmful to generations yet unborn. METHODS O F WASTE TREATMENT
STORAGE IN TANKS.At production plants high-level and longlived radioactive wastes have been and are being stored in underground tanks a t relatively high cost, These wastes have reclamation value (16) and research is being carried out to determine the feasibility of recovering important products contained in them. In the meantime high-level wastes are being stored in tanks built of materials which will resist forces of corrosion from within and uithout. It is expected that they mill remain tight for many decades. Provision is made for monitoring, EO that the first evidence of leakage will be detected. The hazard of minute leaks can be minimized by intelligent preventive measures. If, however, the first leak were merely a portent of a generally defective condition of the container, a serious situation might follow. That is why great care is taken in selecting the location of a u-aste storage facility, why the geology of the area is carefully studied in advance of construction and thereafter, and why the downstream potentialities for affecting ground water are carefully appraised against the contingency of a slon leak or a serious accident which might conceivably release large volumes of ~ 1aste . to substrata. So long as long-lived radioactive materials are stored underground, there will bc nced for supervision over these wastes. Such supervision may be required for generations. Policies, procedures, and products may change but these waste products cannot be forgotten or neglected. EVAPORATION. Evaporation ( I d ) is a common and effective method of reducing volume of radioactive wastes, but is relatively expensive. The cutoff point a t which some other less expensive process should be used must be established with much care. The high level of radioactivity in the residues of evapo-
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Industrial Process Water
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rators often necessitates storage in containers which are shielded until sufficient decay takes place to permit safe handling for ultimate disposal. IONEXCHANGE.The use of ion exchange materials is another means of decontaminating wastes of various levels of activity. It has limitations (6) and presents the problem of ultimate disposal of the spent material. COPRECIPITATION, Coprecipitation (6j processes in multiple cycles using coagulants is still a third method of decontamination. Usually the sludges which are formed are given further treatment and are partially dewatered for storage pending ultimate disposal. Currently there is interest (18)in the possible use of these and other radioactive concentrates as sources of energy to sterilize foods and t o accelerate chemical processes. Research in this field is active. ULTIMATE DISPOSAL OF RADIOACTIVE WASTES
4
E
The ultimate disposal of radioactive wastes presents some real problems for the industry both from the standpoint of costs and environmental safety. Several possible methods have their advantages, their disadvantages, and their advocates. Among these methods are land burial, sea disposal, and incineration. LANDBURIAL. The disposal of radioactive wastes by burial has merit, provided the wastes have low recovery value and the work is done with adequate consideration of hazards involved. A burial ground for high-level wastes should be in soils which are tight, so that leakage to adjacent areas will be a minimum and a t a low rate. A burial ground near creviced or cavernous limestone, over a fault, or in gravelly soils through which seepage water would travel rapidly is obviously not satisfactory. The soil preferably should contain material which has the property of absorbing radioactivity. The capacity and limitations of the soil in this regard should be thoroughly evaluated, particularly with reference to the type of radioactive wastes which are t o be released. Records should be kept as to the nature, location and activity, and prior shielding of all buried material. It is important that the depth of burial be planned so that cover will give adequate shielding a t the surface. Burial grounds are restricted areas and are adequately fenced against access by animals and unauthorized humans. Consideration is being given to the policy and economic aspects of establishing designated burial grounds to serve several Atomic Energy Commission areas. The selection and layout of the burial ground should be well planned with reference to its operation. Where it has been demonstrated that rail shipment is cheaper than other methods of transport, the construction of a long trench parallel to the burial ground siding would permit direct disposal from the cars. Some consideration has been given to storage of packaged radioactive wastes in selected dry caves and abandoned mines. While such a system has some merit, preliminary studies indicate t h a t costs in transport, shielding, and handling probably would be higher than for land burial. A t t h e Knolls Atomic Power Laboratory the handling, storage, and shipment for ultimate disposal of radioactive wastes have been simplified by baling such wastes as paper, cardboard, and rags, which previously were incinerated. SEADISPOSAL. To date, along the Atlantic and Pacific Coasts, there has been some disposal of radioactive wastes t o the sea. This practice has been limited to materials which constituted special problems of burial on land. The wastes have been dumped into deep water off the continental shelf. Usually the radioactive material so disposed of has been surrounded by cement and the shielded mass held in steel drums. While ocean disposal has certain advantages, it needs a thorough evaluation before adoption for general practice in ultimate disposal of highlevel wastes. A contract, was negotiated with Johns Hopkins
December 1953
University t o make such an evaluation, starting in the spring of 1953. Oceanographers, geographers, biologists, and geologists with whom this problem has been discussed have raised some important points which call for much study. There is feeling that considering the limited current knowledge of the seas and their behavior, as well as their potentialities as sources of food and minerals to serve future generations, the seeming advantages of sea disposal of long-lived radioactive wastes may be outweighed by its disadvantages. INCINERATION. Because of the bulk of certain combustible materials which have become radioactive, destruction by incineration has been tried. Usually such materials include papers and cardboard boxes, papers used as wipes or table covering in laboratories, contaminated clothing, bedding material for animals, carcasses of experimental animals, and bench, floor, wall, siding, and roof covering materials. Studies ( 8 ) at the Johns Hopkins Hospital, where wastes from use of radioactive isotopes were disposed of by burning in an ordinary institutional incinerator, revealed that upward of 85% of the activity for certain isotopes such as phosphorus-32 and strontium-90 may be recovered in the ashes. Therefore, they must be handled with care. In order to assure complete protection of the environment, the gases of combustion should be decontaminated t o a low level of radioactivity. This requires costly air-cleaning facilities, including terminal filters of high efficiency. Experience with incinerators at the Argonne and Knolls National Laboratories and at the Los Alamos Scientific Laboratory has shown that the efficiency and operating cost of such units require much consideration. The Bureau of Mines through its Combustion Engineering Laboratory at Pittsburgh has made exhaustive studies ( 7 ) of the problems involved in destruction of radioactive wastes by incineration. Its staff is now developing an incinerator for institutional use which has much promise. This unit will be capable of enlargement for general service at Atomic Energy Commission production and research areas. GASEOUS WASTES
When gaseous effluents are released to the air through high or low stacks, it is important t h a t a sustained effort be made to evaluate the atmospheric dilution which may be expected. The factor of dilution may vary widely during any day and seasonally, depending on the area. A careful study of the meteorology of the specific area and the region may present a pattern of conditions on the basis of which operations involving gaseous contaminants may be directed and controlled. With such data available, the degree of decontamination required may be established within reasonable limits. Good meteorological data are important in arriving a t decisions as to the location and height of stacks, the location of air intake with relation to exhaust system, the spacing between buildings, and even the shape and configuration of buildings. Such data are of great importance in designing heating and ventilation systems and cooling towers, in planning the sequence of construction work, storage of materials, and in evaluating performance limitations due to weather conditions, and work hazards that might be caused by unfavorable or extremes of weather. Remarkable progress has been made in air cleaning within the atomic energy industry. Smokeless stacks used to release radioactive gases to elevations which will give good diffusion are common. They may even be confusing to our neighbors, who never have seen smoke discharge from them. From air-cooled reactors large volumes of irradiated air may be discharged to the atmosphere. The higher the temperature of the gaseous effluents, the greater will be their lifting power and subsequent dilution in the atmosphere. As in the case of the Geological Survey, the Atomic Energy Commission has contracted with the Weather Bureau (29)for assistance in evaluating the meterological aspects of problems related to the release of gaseous effluents from its plants. At certain areas the prime contractor has elected to supplement this
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service and has staff meteorologists studying their local problems. This is the case a t the Savannah River (8), Hanford Works, and Argonne National Laboratory. By having available data as to meteorological characteristics over an area, much can be done to lessen the cost of air-cleaning facilities. For example, if a process which results in a highly contaminated effluent can be put into operation where natural atmospheric dilution factors are a t maximum effectiveness, the degree of cleanup required may be relatively low in comparison with a process which must be in continuous operation. Periods of low wind velocities and prolonged inversion are critical ones. If they can be forecast and operations adjusted accordingly, much can be saved in air-cleaning equipment, especially at a plant which is operated intermittently. Experience has shown that in processes requiring a high degree of air cleanup using such facilities as the Chemical Warfare Service or Atomic Energy Commission filters it is good practice to clean the incoming air and thus lessen the particulate load on the procese air which later is to be decontaminated. In effluent cleaning by filtration, roughing filters are a good investment in proIonging the service life of the more costly high efficiency units. Arthur D. Little, Inc. ( I d ) , has developed an air filter for use in the industry which has an efficiency of 99.99% with a test aerosol 0.3 micron in diameter. One type using an asbestos and Kraft paper filter medium is usable for air temperatures up to 275” F. -4newer one using glass fibers has the same performance efficiencies and can treat gases a t temperatures of 500’ F. or higher. A report on this new glass fiber medium is in preparation. Dust loading (11) in the atmosphere is a n important consideration in the selection of plant location and of air-cleaning equipment. Construction of roads and excavation for structures may disturb otherwise relatively stable soils and care should be taken to minimize such disturbances. Data as to particle size in both the raw air and the process effluent are essential to selection of efficient and economical air-cleaning facilities. In the case of radioactive contamination, information as to distribution of particle sizes, maM, and activity is extremely important. In dealing with radioactive materials considerably more attention than in most industries must be given to small-size particulates, even in the submicron ranges. The behavior of contaminants of small size in the atmosphere, in air-cleaning processes, and in the human body are not too well understood. This is the reason the Atomic Energy Commission, on recommendation of its Stack Gas Working Group, sponsored publication of a “Handbook on Aerosols” (a), which includes selected reports on research carried out during Korld War I1 for the Office of Scientific Research, declassified especially for this service. A research contract on the behavior of aerosols has been in progress a t the University of Illinois for nearly 3 years and has attracted much attention among research workers in air cleaning ( l a ) . There is need of better and uniform air sampling techniques and sampling paper to serve the industry. Arthur D. Little, Inc., is working on the development of standards for filter papers adequate to resolve this problem. The investment in air-cleaning facilities a t Atomic Energy Commission plants is substantial. Early experience demonstrated that often standard equipment m-as not adequate to remove all contaminated material necessary to meet the strict standards which had been set up. To evaluate this situation and to assist those serving the industry to have more specific criteria on which to base specifications for air-cleaning facilities, the School of Public Health of Harvard University, under A4tomicEnergy Commission contract, has established an air-cleaning laboratory where during the past 3 years very valuable research and testing work has been carried out. The staff of this laboratory has visited most Atomic Energy Commission production and research areas and have made recommendations for improvements in air cleaning. I n order t o make the results of their research available to 2676
all concerned in air cleaning within the industry, the Harvard group have conducted three well attended seminars on air cleaning and prepared for general distribution a handbook on air cleaning (9). FALL-OUT OF RADIOACTIVE MATERIAL
Contamination of the atmosphere by radioactive particulates following bursts of atomic bombs a t the Eniwetok and Nevada testing stations and elsewhere is the subject of much research by Atomic Energy Commission and its contractors. Comiderable information on this subject was given in the January 1953 semiannual report (1)of the commission to the Congress. The character, activity, and significance, cumulatively, of the fall-out material are important items to an evaluation of the environmental problems of the industry. At the School of Engineering Sciences, Harvard University, research has been under way for more than a year to determine the fate of radioactivity in selected water supply reservoirs and certain streams in Mamachusetts (17’). Preliminary indications are that much of the fall-out debris settles to the bottom of reservoirs. The effect of the spring and fall turnovers of the reservoirs on the water drawn from them is t o be studied. To date in all instances the levels of activity found were within permissible limits set for drinking water. Even these low levels may, however, be of significance in certain sensitive industries such as the manufacture of photographic paper. EMERGENCY CONSIDERATIONS
In considering environmental conditions in relation t o disposal of waste products from the atomic energy industry, it is important to appraise the problem Fhich would have to be faced in case of a serious incident resulting in release of substantial quantities of radioactive materials of all levels of activity. Provided the meteorology, hydrology, and geology of the area and its environs have been studied and are well understood, the impact of such a contingency can be approximated in sufficient degree to permit formulation of plans for emergency action. The close working relations b e b e e n the staff of the Atomic Energy Commission and representatives of the federal agencies previously mentioned, each of which has had experience in dealing B-ith hazards in the industrial field, give assurance that if and when such an emergency arises prompt and intelligent action can be taken in the public interest. CONCLUSION
The environmental problems of the atomic energy industry, especially in so far as treatment and disposal of radioactive waste are concerned, are unique. They require, and are receiving, special consideration. Problems presented are the basis of much research sponsored by the Atomic Energy Commission, its contractors, its national laboratories, private research institutions, and federal agencies. An organized effort is made to cooperate with public officials interested and concerned in these problems and to assist them in attaining a better understanding of the industry’s policies, technology, and terms. I t is confidently believed that this is an intelligent approach. 4 s the uses of nuclear energy by private competitive industry expand, the newer problems which will surely arise n ill be capable of solution with minimum risks to our people and our nation’s resources. LITERATURE CITED
(1) Atomic Energy Commission, “Assuring Public Safety in Con-
tinental Weapons Tests,” January 1953.
( 2 ) Atomic Energy Commission, “Behavior of Institutional Inciner-
ators When Used to Burn Radioactive Wastes,” Unclassified Document NYO 4517. (3) Atomic Energy Commission, “Handbook on Aerosols,” 1950. (4) Atomic Energy Commission, “Handling of Radioactive Wastes in the Atomic Energy Program.” ( 5 ) Ayres, J. A., IXD.ENQ.CHEX, 43, 1526--31 (1951).
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Industrial Process Water (6) Christenson, G. W.,et al., Ibid., 43, 1509-19 (1951). (7) Corey, R. C., et aE., “Experimental Study of Effects of Tangential Orifice of Air,” Air Pollution Control Association, Baltimore, Md., May 26, 1952. (8) Falck, L.,et al., “Savannah River Plant Stack Gas Dispersion and Micro-Climate Survey,” Atomic Energy Commission, AEC DP-19 (June 1953). (9) Friedlander, S. K.,et al., “Handbook on Air Cleaning,” Atomic Energy Commission, 1952. (10) Hatch, L. P., American-Scientist, 41, 410-21 (July 1953). (11) Humphrey, P. A., “Meteorological Program a t National Reactor Testing Station,” Sanitary Engineering Conference, Chicago, September 1952. (12) McCullough, G. E., IND.ENG.CHEM.,43, 1505-9 (1951). (13) Ranz, W. E., and Johnstone, H. F., “Some Aspects of the Physical Behavior of Atmosphere Aerosols,” Proc. 2nd Natl. Air Pollution Symposium, p. 35, Pasadena, Calif., May 5-6, 1952.
(14) Smith, W.J., “Iron-Combustible and Chemical Resistant -411’ Filters for High and Low Temperature Use,” Minutes of Air Cleaning Seminar, A.E.C., Ames, Iowa, September 1952, in press. (15) Stanford Research Institute, “The Industrial Utilization of Fission Products, a Prospectus for RIanagement,” R4arch 1951. (16) Theis, C. V., “Work of the Geological Survey in Connection with Sanitary Engineering Problems of the A.E.C.,” Atomic Energy Commission, 129. (17) Thomas, H.A,, et al., J. Am. Water Works Assoc., 46, No. 6, 562-8 (1953). (18) Urban, Walter, Food Eng. (February & March 1953). (19) White, Fred, “The Weather Bureau and the Atomic Energy Commission,” Atomic Energy Commission, September 1952. RECEIVED for review March 14, 1953.
ACCEPTEDAugust 29, 1953.
Waste Disposal. in the Los Angeles Area Two factors have had material influence on policies controlling industrial waste disposal in the sewerage systems of the metropolitan area of Los Angeles County: the wide range of chemical wastes acceptable for ocean disposal but not for disposal to ground waters or fresh water supplies and the short supply of acceptable water demanding integrated conservation and re-use of industrial process waters. The flexibility of the two major sewerage networks and availability of ocean disposal have permitted the unprecedented industrial expansion of the area to be met without serious difficulty.
A. M. RAWN County Sanitation Districts of Los Angeles County, Los Angeles, Calif.
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N THE Los Angeles area industrial wastes may be broadly classified in two categories: liquids containing little or no settleable solids, which may be disposed of through sewers to final treatment and disposal, and solid or semisolid wastes to be discharged a t sea or a t legally licensed land disposal sites. The two classifications overlap somewhat, in that a number of industrial wastes may, with pretreatment, be discharged in part into the sewerage system but in their pretreatment there is generated a solid waste which falls into the second classification. SEWERAGE AGENCIES
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The Los Angeles metropolitan area is served by two principal sewerage agencies: The first is the city of Los Angeles, under whose control is the system which serves the major portion of that city, the major portion of the city of Vernon, and the cities of Burbank, Glendale, Beverly Hills, Culver City, Santa Monica, and San Fernando. This vast city system serves an area of more than 500 square miles containing a population of nearly 2,500,000 as well as the major portion of the industries which make Los Angeles and its metropolitan area third in manufacturers in the nation. There are two termini to the city’s system, the larger near E l Segundo discharging to Santa Monica Bay, where the city has constructed a high-rate activated sludge plant with a capacity of about 250,000,000 gallons per day and an ocean outfall extended seaward some 4000 feet. The second is a small primary plant December 1953
on Terminal Island, Wilmington, with a capacity approximating 10,000,000gallons per day and 1000-foot outfall into the harbor. The present flow to the plant at El Segundo is about 240,000,000 and that to the Terminal Island plant about 8,000,000 gallons per day. The second main system in the area is provided and administered jointly by 11 County Sanitation Districts. It serves an area of a little over 500 square miles and a population in excess of 2,000,000. Thirty-five of the 45 incorporated cities in Los Angeles County are served in whole or in part by the districts’ system, as are large tracts of unincorporated but densely populated areas. A part of the industrial activity of the metropolitan area almost equal t o that in Los Angeles city originates in the area served by the sanitation districts. The sanitation districts operate a single primary subsidence, separate sludge digestion plant near Lomita. The effluent from the plant flows through a tunnel under the Palos Verdes Hills and is discharged into the ocean 5000 feet off the south rocky shore a t a depth of 110 feet. Currently the plant and outfall facilities are being greatly expanded. Flow a t the districts’ plant approximates 160,000,000 gallons per day. These two large sewerage systems are of the separate type, in that they are used only to carry sanitary sewage and industrial wastes. The wisdom of this is perfectly apparent when one compares the average daily sewage flow from the area of about 400,000,000 gallons per day with the enormous storm flows that
INDUSTRIAL AND ENGINEERING CHEMISTRY
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