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crease in diameter may become almost impossible to meet.

(c) No credit is given for the use of high stacks as a valued aid in reducing the effect of particulate matter emitted.

(d) Apparent disregard of the mounting cost and size of equipment as absolute perfection is approached. Figure 3 shows this effect for electrostatic dust collecting equipment.

Items (c) and (d) combine to have a particularly adverse effect on the powerplant designer, since he is barred from balancing dollars spent in two different ways to produce the best overall result. It should be evident that the utility industry can do many things to satisfy public requirements. The public should, however, at the same time be aware that increased costs from nonproductive facilities ultimately will be borne by them in the form of higher rates. In simple justice to the public, those who seek to establish limits should leave the door open to producing the overall result in the most. economic manner.

CONCLUSION

The principal new factor affecting air pollution from powerplants and its control that has appeared in the past decade is the shift to larger individual units and to larger total plants. Figure 4 shows the stack heights, and the capacity of the coal-fired units which they serve, for a number of plants built

or modified during the past 6 years. Contrasting symbols show the same data for some plants which are now in the design stage and which will be placed in service prior to 1966. The general upward trend in stack height is unmistakable, although differences in plant sites, fuel burned, population density, proximity to airports, and possibly other variables, create wide individual differences among the plants.

It can be seen that the power industry observed this new factor and promptly moved to maintain optimum community relations, by disposing of the vast quantities of gases from these new plants in a highly satisfactory manner. This has involved stacks which were larger than any previously built in the United States, such as the 683-foot structures at Clifty Creek. Structures of this magnitude introduce new problems in both their construction and maintenance, as well as adding significantly to the original cost of the plant. The forward-looking utility accepts these costs and design problems in full knowledge of its community responsibility.

It is our feeling that the freedom to approach these problems openly and honestly, seeking for an optimum solution which includes due consideration of the community, the rate-payers, and the stockholders, is a valuable one. This freedom should not be lost to those who would promote arbitrary regulation in a field which has developed, and apparently will continue to develop, as rapidly as this one.

Prepared Discussion: AIR
AIR POLLUTION FROM
POWERPLANTS AND ITS CONTROL

HARRY PERRY

Assistant Chief, Division of Bituminous Coal Bureau of Mines, U.S. Department of the Interior Washington, D.C.

Mr. Frankenberg has given us a brief but very lucid account of the steps taken by the electric utility industry to keep pollution within a limit acceptable to the communities it serves. The problem of balancing economic factors against excessive control is clearly brought forth, and we agree that this needs to be stressed in the consideration of any air pollution problems. Just as new developments in commercial techniques and equipment indicate the need for review of our standards, likewise, the ever-increasing size of powerplant installations poses problems that may require periodic reappraisal of previously acceptable standards.

On a year-round basis, energy released by combustion of coal, petroleum, and natural gas, the so-called fossil fuels, powers about 82 percent of the electric generators supplying this Nation's vast electrical-energy market. Projections of electric energy demand indicate that the past tendency for it to double roughly every 10 years can be expected to continue through the remainder of this century; other projections indicate that fossil-fuel consumption will continue to rise almost in proportion, at least for the next decade or so. Thereafter, nuclear energy release may begin to be a significant and steadily growing factor. Even so, projections show increased fossil-fuel consumption throughout the remainder of the present century. Because the Bureau of Mines has a number of responsibilities concerning production, processing, and utilization of fossil fuels, we have a keen concern in their relation to air pollution.

To the extent that added conventional thermal powerplant capacity is installed and operated in or near urban areas, it will tend to add some increment

of pollutants to the surrounding atmosphere. Production of nitrogen oxides is common to combustion of each of the three kinds of fossil fuels. Production of sulfur oxides is common to combustion of petroleum products, especially residual fuel oils, and to combustion of coal. We have much to learn yet about the more subtle roles of these oxides in urban air pollution although we can accept categorically that, in sufficient concentrations, they can impair man's health and degrade his property. Still other pollutants of significance may be present in powerplant stack emissions, but we don't yet know. I should hasten to add that there is a lack of general agreement among medical experts on the significance of man's breathing air that contains small amounts of nitrogen and sulfur oxides. I should also point out that powerplants are by no means the sole source of nitrogen and sulfur oxides in urban atmospheres. Powerplant management characteristically tends to protect the area it serves from adverse effects of powerplant stack emissions. A review of the industry's plant locations and equipment installations, and its history of concern and action over air pollution problems, attest to this.

The electric utilities industry has always been in the forefront of the industrial community in its efforts to reduce stack emission of air pollutants to acceptably low levels. Obviously, the principals know, and the public should know, that a large part of the costs involved in stack emission control will eventually be passed on to the consuming public. Admittedly, electric utility companies have an advantage over many other industries in their communities in that it is possible for them to cover the cost of improved operational controls through

an increase in the price of their product, provided they can convince the appropriate public utilities commission of the necessity for such increases. Nevertheless, I need not tell you how "cost conscious" the public utilities are; their record of holding the price line in the face of inflation is testimony to their efforts.

It is perhaps fortuitous that the major industrial consumer of fossil fuels should be thus favorably situated. However, let me hasten to add that electric utility management cannot be, and indeed does not try to be, complacent and self-assured in this matter. Being an industrial neighbor, often the principal industrial neighbor, of residential areas is no sinecure. And, a sincere desire by electric utilities to discharge relatively pollutant-free stack emissions is not tantamount to attainment. Where tools are available for economic control, electric utilities use them. Thus, smoke and flyash from utility company stacks are rarely problems in these times. On the other hand, where are the tools for economic control of sulfur and nitrogen oxides? And, for that matter, just how much control is needed? The former question is of direct concern to the Bureau of Mines, because it involves a problem related to consumption of the three major fossil fuels.

As previously indicated, the sulfur oxides problem is one that will be with us for a long time. The removal of sulfur-bearing compounds from coal or oil is both difficult and costly. Considerable prog

ress has been made in coal preparation methods that are effective in removing part of the sulfur-bearing materials. Economically feasible methods for removing sulfur oxides from the stack gases have not, as yet, been developed.

Recognizing a widespread and difficult problem concerning a phase of minerals-use technology, the Bureau of Mines is doing something about it. Jointly with the Public Health Service, and through support they provide under Public Law 84-159 as amended, we are presently investigating in cooperation with certain utility companies the composition of flue gas in large coal-burning steam boilers. Additionally, through cooperative-fund agreements with PHS, we have been developing and studying the operational and economic feasibility of a "dry scrubbing" procedure. We also are looking into the effect of this and other possible economic means for lowering the nitrogen oxides content of flue gases. We hope that we can play an important role in better elucidation of what it is we are concerned with, and how we best can deal technologically with whatever components of powerplant stack emissions need source control. When a rough sketch of the tools that are really necessary can be drawn, I am confident that equipment makers will be quick to pick up, perfect, and produce those tools for economic control, and that powerplant management will be ready customers for the product.

AIR POLLUTION FROM THE MUNICIPALITY AND

THE HOME AND ITS CONTROL

ARTHUR J. BENLINE Commissioner, Department of Air Pollution Control New York, N.Y.

In order that there will be no misunderstanding, let me first explain that when we say "home," we are actually speaking of all residential properties, ranging from the one-family home to multipleapartment dwellings and hotels. Air pollution attributable to homes originates with two basic operations. These are the operation of heating plants and of refuse disposal or incineration equipment. There are air pollution problems encountered in residential properties which are minor from the point of view of the infrequency with which they may be encountered. Under certain circumstances, however, they may actually approach major importance. These are usually the nuisance type of condition, resulting, for example, from the poor placement of ventilators in buildings with basement garages.

More and more such buildings

are being built around the country today and, because existing legislation is not geared to this type of problem, obtaining correction is often a cumbersome or difficult operation. Other examples are the discharge of lint, odors, steam, and so forth, from such domestic devices as domestic clothes dryers or air conditioners. Then, of course, there is the problem of dust emissions encountered during the construction or demolition of residential and other properties. Occasionally an odor problem is encountered when the vent pipe on an oil storage tank is improperly placed, leading to an odor nuisance at the time when the oil tank is being filled. Most of these nuisance type conditions can be corrected by either relocation of the point of emission, or of the device itself to a location where it will not be a nuisance to its neighbors. Some of the dust incidental to construction or demolition of buildings is almost unavoidable, but a good deal of

it can be controlled effectively by proper operation. The construction of tight chutes for disposal of debris will prevent loss to a good degree. The prompt and thorough use of hoses for the wetting down of materials also will help. The proper use of tarpaulins as wind baffles also will, in many cases, provide a solution to such problems. Proper supervision of trucking to and from the construction or demolition site, to insure that trucks are not overloaded, is important to avoid dust nuisances.

Since many residential properties are of the mixed occupancy type that includes stores and other retail establishments, we have a host of air pollution problems originating purely from the various types of businesses that may be found in such buildings. Restaurants, laundries of either the commercial or coin-operating type, coin-operated or conventional drycleaning establishments, fish markets, and so forth, all are illustrations that I just mention in passing. Since they are only incidental to the operation of residential properties, and then only occasionally, I will go no further along these lines.

Many municipalities now are operating residential housing properties, and therefore find themselves in the peculiar position of having one agency operating properties that create pollution, while another agency of the same municipality is charged with responsibility for reducing and controlling air pollution. Even more frequently, municipalities contribute to their own air pollution problem from the operation of sewage treatment plants, asphalt plants, incinerators, powerplants, vehicles used in public transportation, and similar installations. From what I have seen and heard in some areas, the public may be justified in saying that the municipality gives private enterprise pretty close competi

tion for the unenviable title of "worst offender." Private ownership of property stems from the desire to make a profit. This, of course, is not the case with the municipality that owns or operates properties of various kinds. The municipality finds itself “in business," if I may use that expression, because of the need or the desire to be of service to its public. If Caesar's wife must be above reproach, a city-owned installation should also be above reproach. The substandard city-owned installation puts its air pollution control agency in an unenviable position, for reasons that are obvious. Incidentally, a slightly paradoxical situation prevails. A municipality that does not operate a public incinerator, powerplant, or sewerage treatment plant, still may be responsible for air pollution by virtue of the fact that such services are not performed by them. The city without an effective public refuse collection and disposal system, for example, leaves homeowners with little alternative but to employ backyard incineration as a means of disposal. It is unnecessary to tell you how much of an air pollution problem backyard incineration can create in a city. As a further illustration of this paradox, where adequate and effective public transportation facilities are not provided, the public will use private cars, and then roadways are choked with traffic, and the atmosphere is choked with exhaust fumes. Now let us look at the other face of the paradox. Where the city has public transportation, pollution problems are created by the diesel buses that it operates, or by the powerplants required to generate the electricity to run its transit system. Where the city provides municipal refuse collection and incineration, air pollution frequently is created from the operation of large incinerators. Any air pollution control official, however, if given a choice, would much rather contend with air pollution originating from a few large plants than from a multitude of smaller sources of pollution. It is easier to maintain control over one city incinerator than over thousands of small incinerators scattered throughout the city.

Getting down to specifics, the methods for the correction of air pollution from boilers are pretty well known. The past half century of engineering progress has made available the knowledge, and the wherewithal, to solve practically any air pollution problems stemming from boilers. The control agency that has a legally effective permit and control system is prepared to prevent or to minimize new local sources of air pollution. Taking steps to

insure that boilers are of the right design and size for the job is the first important measure. After the installation has been made, however, the job does not end. Steps must still be taken to insure that these boilers are properly maintained and properly operated. It is routine for the careless or stupid fireman to upset all the good work that the engineer and the manufacturer have put into the construction of the boiler. There may be a time in the distant future when boilers will be so designed and automated as to eliminate completely the factor of the human element. Perhaps, even before that day arrives, atomic energy, as a source of heat and power, may render boilers obsolete. But we can't sit back and wait for the millennium; today's problems have to be solved today. Solving a problem involves two steps. First, analyzing the problem and ascertaining the cause; and second, getting the cause of the problem corrected. This sounds simple, doesn't it? But before anybody in the audience tells me that this is not simple, let me say for the record that I know it is not always a simple matter to find the cause in many cases. The control agency must have its own staff make a careful survey of the problem; in other cases, the owner of the offending plant must be required to call in his own consulting engineer to study the problem, and there are many cases where both steps may take place simultaneously. No general rule can be laid down as to the method of approach, since circumstances vary from one community and situation to another. Once the cause has been ascertained, then several techniques or a combination of techniques may be employed in getting the cause corrected, such as cooperation, persuasion, education, or enforcement. It is not at all unusual to encounter a situation where the property owner has no knowledge of the fact that he is causing air pollution. Apprising him of the fact and appealing to his moral responsibility or civic pride should suffice, and often does, to gain correction. Where a little extra persuasion is needed, simple arithmetic showing him in dollars and cents how much he is wasting by the incomplete combustion of his fuel should get the necessary work done. Incidentally, it is rather difficult to convince the general public that every smoking stack is not really smoking out of malice aforethought. From my own experiences, I have found that on a great many occasions the offender is completely unaware of his offense until the control official brings it to his attention.

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