Nearly 700 papers will be presented, either orally or published, at five concurrent daily sessions. The bulk of these come from 46 nations and 12 international organizations.

Regarding its purposes, Secretary Udall said, "President Johnson, in calling the Conference, stressed that a massive, cooperative assault should be launched within the range of existing technology to meet world water needs. Thus, this Conference will be a major planning session to encourage concrete action by individual nations and by international organizations and nations working together."

Because the meeting is more than an exchange of technical information, many nations are sending cabinet-level officials with water resource

responsibility in their countries. Special sessions are planned for these ministers.

The Governors of the 50 States have also been invited to attend or send representatives.

Among the representatives of the Bureau of Reclamation who will deliver papers are: Commissioner Floyd E. Dominy and Assistant Commissioner Gilbert G. Stamm.

In addition to members of official delegations and accredited international observers, Conference sessions (to be held at the Sheraton-Park Hotel) will be open to those who register in advance prior to May 19. Anyone desiring to attend should write: Secretary-General, International Conference on Water for Peace, Room 1318, Department of State, Washington, D.C., 20520. # # #

But did you ever stop to think what would happen if water supplies for industrial plants dried up or were destroyed by some catastrophe? The results might be less irritating to the individual person, but they would be devastating for civilization. Industry depends on water just as life itself does.

Without water for industry, our culture would return to a primitive level; we would eventually have to go hunting with bows and arrows and return to cultivating the soil with a sharpened stick. We would not have farm machinery to use in growing food. We would not have trucks, trains, or boats to transport food to the consumer.

All such machines require steel, and to manufacture a ton of steel requires 270 tons of water. Ten gallons of water are needed to produce 1 gallon of gasoline with which to operate the machines; 920 tons of water are needed to make a ton of rayon fiber. A ton of sulfite pulp to make paper requires 200 tons of water.

Today, industry needs water in fantastic quantities and the demand is skyrocketing. It has increased tenfold since 1900, although the population has little more than doubled. Industries in the United States use 700 gallons per person per day; an individual person in his home for drinking, washing, and other household purposes uses an average of only 50 or 60 gallons a day. Ninetyfour percent of industrial water is used for cooling, and most of this can be used again.

There is a widespread notion that U.S. industry will soon be faced with a serious permanent water shortage. This is not true, for the overall supply exceeds the demand and will continue to do so in the foreseeable future. However, there may not be enough water at a given place in a given season, at a price that industry is willing to pay. Every plant will not have available all the cheap water it can use.

Where does industry find the water it needs? Some smaller companies get it from public supply systems. This water is generally used by industries that require small quantities of high-quality water and are in locations where suitable water cannot easily be obtained from wells.

Very large industries usually find it more economical to set up their own supply systems-if they are near adequate sources of water from lakes,

Some industries use much more water than others. For example, the electric power industry uses almost 10 times as much as the chemical industry, which is the second largest user. The amount of water used depends on the size of the industry and on how the water is used. Industry uses water for cooling, processing, and for sanitation and services.

The electric power industry cools the steam from turbines with water. The cooled steam condenses, thus reducing the back pressure on the turbines, and increasing the efficiency of the plant. The chemical, petroleum-refining, and steel industries also use large quantities of cooling water. Water for cooling does not have to be of especially high quality.

Water for processing is either incorporated in

the product, as in soft drinks or canned fruit, or it comes in contact with the product during manufacture. For certain industries, process water would obviously have to be of very high quality. The pulp-and-paper industry uses water for washing the pulpwood, cooking the woodchips, and transporting the pulp to the paper machines. Such water would not have to be quite as pure and free from dissolved solids or bacteria as water used in food packing plants, or in the making of synthetic textiles.

Water is also used in factories for sanitation and services to clean and maintain the plant. Drinking water, showers for workers, lawn watering and firefighting are some examples of this kind of use. Some industries need water only for sanitation and services. Such plants usually use water from public supply systems-their water needs are so moderate it would not pay them to develop their own systems.

Even within an industry the amount of water needed to make a given product varies widely. The reasons for this wide range are complex. Take carbon-black, for instance. This is the soot produced by partial combustion of natural gas, and it is one of the important ingredients in rubber tires, shoe polish, carbon paper, and typewriter ribbons.

The contact process of carbon-black manufacture requires only 0.14 gallons per pound-in contrast, the furnace process requires 3.26 gallons per pound. Hot carbon-black-laden gases from the furnace process are cooled with a water spray, but cooling water is not required in the contact process.

Some other industries, such as the aluminum industry, require large quantities of electricity. Water requirements of a plant are greater if the electricity is generated at the plant than if it is purchased.

The water intake of a plant may be reduced by using the water several times over. This reuse is what makes it so hard to estimate the relationship between supply and demand in water planning. Some petroleum refineries use the same water to cool the hot gas as many as 50 times. Such reuse reduces the cooling water intake to one fiftieth, and the total water intake to one-twelfth of that needed without recirculation.

Water used for cooling many times over is greatly reduced in quantity. In the cooling process, some water is constantly being lost due to evaporation. Some petroleum refineries consume almost all the cooling water through evaporation.

Reduces Quantity

Reuse not only reduces the quantity of water, it has a bad effect on its quality. All natural water contains dissolved minerals, and some water con

tains more than others. As the circulated water evaporates, the dissolved minerals become concentrated in the water that is left. When the concentration of dissolved minerals reaches a certain level, this water must be discarded.

Some industries can use more highly mineralized water than others. However, incoming water having a high mineral content can be reused fewer times than water having a low mineral content. If the local water supply has a high mineral content and cannot be reused, more water will be needed.

Sometimes saline (salty) water may be used for cooling, if the water is to be used only once. However, the machinery for using saline water must be designed to resist rusting. Saline water is used only when fresh water is not available at a reasonable cost, because rust-resistant machinery is more expensive than ordinary machinery.

Many plants all using the same stream for cooling purposes can seriously damage its water quality. The Mahoning River in eastern Ohio is an outstanding example. Several steel mills use this stream as a source of water for cooling and return the warmed water to the stream. A water temperature of 117° F. was observed in July 1941.

These mills heated the water sufficiently in December 1949, to increase the average water temperature from 35° F. at Leavittsburg, above the mills,

to 84° F. at Lowelville, below the mills.

You may wonder why we describe this artificially warmed water as of poor quality. One reason is that the warmed water may upset or harm fish and other aquatic life in the river. Another reason is that warm water is unsuitable for some domestic or industrial uses.

Some industries require a high standard of quality of water, but others can use water of poor to medium quality. In general, calcium and magnesium compounds are undesirable in process water, especially if the water is used hot, because a scale will be deposited in the machinery, just as scale forms in teakettles. Certain minerals are likely to stain the product and are therefore undesirable. If the product is a synthetic fiber such as rayon or acetate, iron and manganese interfere with bleaching and dyeing. Synthetic fibers require a very high quality water-soft, and low in mineral content.

One very important use of water by industry, is for disposal of the waste products of processing. At one time streamflows were adequate to dilute, dissolve, or carry away these wastes. But now, many of the larger rivers in the United States are depleted by use and overloaded with wastes. This pollution not only upsets the delicate balance of nature between plants, insects, and fish, it also poses problems of water quality for the people and industries downstream.

There are various kinds of industrial waste pollution. Organic wastes mostly come from food packing plants and also from pulpmills. Inorganic waste consists of chemicals-acids, cyanides, etc.-and comes from many different industries. Then there are insoluble particles (such as mineral tailings) which may make the water turbid or settle at the bottom, smothering purifying organisms. Finally, there is heat, which we have already mentioned as a form of pollution.

Industries generally are aware of the problems created by waste disposal in rivers and are trying to help in pollution abatement. For instance, the pulp and paper industry, which used to be one of the worst offenders, has cut the pollution load per ton of product in half by spending millions of dollars on treatment facilities.

Predisposal Treatment

Other industries and groups of industries are doing research on predisposal treatment of their waste products before disposing of them. Such

Food processing plants must have clean water supplies. Checking the quality of the potatoes in his plant at Billings, Mont., is Phil Werle, manager.

research and treatment are expensive, however, and add to the cost of the product. It is not surprising that some medium-sized industries as yet do little or nothing about the problem.

Now you begin to see how complex the industrial water picture is. National averages of industrial water use don't mean very much. Comparisons of supply and demand, even in a local area, are not very meaningful unless the quality of the supply and the quality requirements of the industry are considered. Requirements vary from plant to plant, depending on the product, the process used, the kind of water available, and the amount of recirculation practiced. An accurate water balance of use versus demand would require a detailed study of local conditions and the industries concerned.

Forecasting industrial water use very far into the future is even more difficult. Products and processes become obsolete. Recirculation and other water-use practices change with the changing times. For example, the present trend in textiles is to replace natural fibers with synthetic materials whose manufacture requires larger quantities of water.