in the industrial use, the water may not be polluted, but in another case, perhaps for aquatic life purposes, the same water may be polluted? Is this not possible? If by "pollution" we refer to elements in the water which make it undesirable or impossible of use for a particular purpose?

Dr. WOLLMAN. This is a matter of arbitrary definition. One can say that pollution exists whenever the quality of water is different from what it would exist in its natural state if it had not been used by man at all.

That definition would not coincide with the one you have just proposed.

Senator MILLER. Well, which one do you propose?

Dr. WOLLMAN. I would propose the definition that would relate to the overall usability of water within the whole economy.

Senator MUSKIE. Would the Senator yield at that point, just for one question along the same line?

Senator MILLER. Yes.

Senator MUSKIE. In other words, your concern, as I understand it, Dr. Wollman, is with not only a current use to which the water might be applied, but to the standards of quality of the water which would make it available for multiple uses?

Dr. WOLLMAN. I would say our water quality has to be such that it imposes a minimum constraint on the development of the economy insofar as that economy is going to develop based upon the availability of all resources and our knowledge, namely, our technology.

Senator MILLER. I would like to know it, when you talk about the development or overall development of our economy, you are including only the industrial development, or are you including the recreational development and the acquatic development also?

Dr. WOLLMAN. I am including everything, including the purely esthetic elements that may be derived from water. I am making my definition as broad as is conceivable.

Senator MILLER. Well, indeed, you are. And this concerns me, because I can see where, to be meaningful in coming up with a legislative answer to these problems, we are going to be involved in a weighing of the equities, so to speak.

That, perhaps, for the esthetics of the situation, we may be willing to do certain things. But there will be a point beyond which it would not be feasible in terms of industrial development.

Is this not going to be our ultimate problem, when we try to legislate in this area?

Dr. WOLLMAN. I think you will most certainly have to make compromises all along the line. And the question is how you will make these evaluations, and with what perspective you will make them.

Because, obviously, we are going to interfere with this natural quality of water, no matter what we do, or what we fail to do.

Senator MILLER. Thank you very much.

Senator MUSKIE. I think it would be appropriate to make just one further point, Dr. Wollman.

In the projections you are about to give us, you are not using natural purity of water as a standard, but, rather, you are using, or you are beginning to discuss, the 1-milligram, 4-milligram, and 6-milligram standards, which are far short of natural purity.

Dr. WOLLMAN. That is true.

Senator BAYH. Mr. Chairman-sir, how are the 1-, 4-, and 6-milligram standards used? Are they used in determining whether further treatment facilities or further purification of water are needed?

Dr. WOLLMAN. I would rather you ask that question of a sanitary engineer on one of the State water quality control boards. I can only give you a vague guess.

Senator BAYH. The reason I ask is that I think it ties in very closely with Senator Miller's question, in that we are dealing with, as the chairman said, minimal standards, and none of these standards, by your previous statement, is sufficient to maintain aquatic life in its full life cycle.

Are we shooting too low in limiting our discussion to these three standards?

Dr. WOLLMAN. One reason we selected a standard of 4 or 6, they serve as a measure of the average for the region as a whole. Our analysis was a regionwide analysis. We divided the United States into 22 regions and treated, in effect, the region as a single point in space. And by saying that there would be 4 milligrams per liter of dissolved oxygen, this allowed us some leeway to have 8 and 12 in parts of the region, and 2 and even 0 in other parts.

This is a rather crude statistical technique of estimation that could hardly be used in a specific river basin for planning. The purpose of these estimates was to develop a rather rough guideline for the Senate over the next 40 years to give them a perspective with respect to what was going to happen to the total of water resources.

One would not use standards as coarse as this in specific planning at specific sites.

Senator BAYH. Then a 4- or 6-milligram condition average could also mean that there were sufficient 8- or 10-milligram periods to sustain life?

Dr. WOLLMAN. That is true.

Senator BAYH. Thank you very much.

Senator MUSKIE. I think it might be helpful at this point if you would define those areas, or if you could get into the record those regions of which you speak, and also relate your 4- and 6-milligram standards to those regions.

Dr. WOLLMAN. I will quickly enumerate the regions that we used, without a precise bounding, because I am sure that most of you are familiar with these regions in their general outline.

We used hydrologic boundaries converted to the closest county equivalents, so that we could use economic and political data with facility.

The 22 regions were based upon the 18 regions that the Bureau of the Census uses in its census of manufacturing water use. We modified the Bureau of Census Division in several cases and extended their 18 to our 22.

These are as follows. And in some cases they represent groups of small basins. In some cases they represent a single, well-defined river basin.

New England, Delaware, and Hudson, Chesapeake Bay, Ohio, eastern Great Lakes, western Great Lakes, upper Mississippi, lower Missouri.

I have combined that group into a larger area which I call the Northeast United States; another group which I call the Southeast consists of the southeast coastal plain, the Cumberland, the Tennessee, the lower Mississippi, and the lower Arkansas White Red; another group which I call the Midcontinent is the upper Missouri, the upper Arkansas White Red, and the western gulf.

There are four that make up the Southwest-the Rio Grande Pecos, the Colorado, the Great Basin, and the South Pacific. South Pacific consists of the seven southern counties of California.

Then there is another major division called the Central Pacific, which is made up of the central Pacific, and that is the remainder of the State of California plus one county in Oregon, and then the Pacific Northwest, which is the remainder of Oregon and Washington and part of the drainage along the western slope of the Continental Divide.

These are the 22 basins. And for each basin we computed the water requirements by first taking national projections of population and gross national product and then translating the national projections into an appropriate regional division. These divisions were made primarily by various Federal agencies having jurisdiction of the particular type of activity. They included the Department of Agriculture, Bureau of Mines, the Department of Commerce, the Federal Power Commission, and so forth.

Now, based on the projections of population and gross national product, and then the division of these national projections into the regional outputs and regional populations, we computed water requirements.

We had to, of course, stipulate a particular level of economic projection, such as a low path of growth, or a medium path of growth, or a high path of growth.

Also there had to be certain assumptions made with respect to the substitutability of product for another. For example, plastics will substitute for paper, and so will aluminum, as a wrapping material. So various assumptions with respect to substitutability are built into these figures. And, of course, they introduce a range of uncertainty in all cases.

Now, by a water requirement, I mean something that has not typically been used as the measure of water requirement. My meaning of water requirement is the sum of two components:

One is the amount of water that is evaporated or transpired to the atmosphere by all of these uses. And the other is the amount of water that has to be mixed with effluent after treatment in order to provide for the designated level of water quality measured by dissolved oxygen in the stream.

This does not give you a measure of withdrawals or intake, which is a measure that is subject to a wide range of variation, depending upon the degree of recirculation. The intake or withdrawal measure fails to incorporate the possibility of higher degrees of recirculation and reuse within the basin. The measure that we have worked with washes out that indeterminacy, and gives us, in effect, a bedrock figure for the amount of water that must be flowing in the stream in order to meet these two objectives.

And, by implication, recirculation can take place infinitely, so long as the waste is treated at the designated level of treatment and so long

as we provide for the designated quality of water in the stream measured by dissolved oxygen content.

So we have a determinant measure of requirement that can be placed against the existing flow of water in the stream. And, therefore, we can stipulate what that flow must be at its minimum in order to maintain the water at the stipulated level of dissolved oxygen and also allow for all of the industrial processes and other uses that will result in evaporation of water to the atmosphere.

Senator MUSKIE. How do the 4- and 6-milligram standards apply to these regions?

Dr. WOLLMAN. We made a variety of estimates based on different economic projections, and these different levels of water quality.

Let me first indicate to you the aggregate for the United States that emerged from these techniques of estimation.

By 1980, in the United States, the aggregate required for 4 milligrams per liter, high economic projections, would be 471 billions of gallons per day. By the year 2000, 4 milligrams per liter, aggregate required flow, would be 893 billion gallons per day.

If we move to 6 milligrams, the required flow in 1980 would be 525 billion gallons per day. And in the year 2000, the figure is 1,026 billion gallons per day.

Let me explain briefly the significance of these numbers.

Our present mean flow over the historical period of record is approximately 1,100 billion gallons per day. This is what we would have if every stream in the Nation were subject to complete regulation to provide for such storage as is necessary, as indicated by a 30- or 40or 50-year period of record, or in some cases somewhat less, depending upon the length of time for streamflow gaging measurements. Senator MUSKIE. This is 1.100 billion gallons per day? Dr. WOLLMAN. That is right.

Senator MUSKIE. Is it fair to say this is the present available supply of fresh water?

Dr. WOLLMAN. This probably exceeds the present this probably is greater than the usable supply. The usable supply is a figure that we really do not have well established.

There has been a rule-of-thumb estimate that we can regulate up to about 50 percent of the mean flow, which would mean that we can regulate up to about 550 billion gallons per day.

And that if there are flows required in excess of 550 billion gallons per day, they are theoretically possible. But the question, then, is: Can you develop enough reservoir sites over the United States in order to control the water in large enough quantity to raise the minimum flow from this level.

Senator MUSKIE. What you are saying is what you are saying

this:

That the other 550 billion gallons a day simply is not in a location which makes it available for predictable demand?

Dr. WOLLMAN. No, I am not saying quite that. I am saying that in order to raise the minimum flow above 550 billion gallons per day, at various places in the United States we will have to construct additional reservoirs. And there is a very large likelihood that we would not be able to acquire enough reservoir sites in all of the various feasible places, because I am sure that in some parts of the country the

present density of population means that we would have to inundate settled places, utilities, communities, and so forth, in order to achieve this high degree of regulation.

Senator MUSKIE. SO, of the 1,100 billion gallons a day that is available in the sense that it exists, you have a rough guess that about half of that is available in any practical sense?

Dr. WOLLMAN. This is not really my guess. This has been the guess of engineers that have been working with this problem. I think that it is probably a rule of thumb that is likely to be stretched in the future, so that we will achieve probably higher degrees of regulation than that 550. But just how far, nobody really knows.

Senator MUSKIE. What is the relationship of that 550 to the 355 billion gallons a day we are now using?

Dr. WOLLMAN. That is a measure of withdrawal, and does not correspond to the measures I have given you, because that withdrawal measure is subject to modification by recirculation, whereas the measures that I have given you are not subject to any modification other than a change in the technology of waste treatment or a change in the amount of waste produced per unit of product.

So the two figures are not directly comparable.

Senator MUSKIE. Would it be fair or accurate to say that we have 550 billion gallons a day available, of which we are using 355 billion? Dr. WOLLMAN. I do not think so. That would not correspond to my measurements at all.

Senator MUSKIE. What are the principal reasons why it would not correspond?

Dr. WOLLMAN. The principal reason is that the 350 is a withdrawal figure that implies a certain amount of reuse. And my figure does not. My figure takes that factor out of consideration. So you cannot reduce my figure by saying let us have more reuse.

I have already accounted for all conceivable reuse in the measure I have given you.

Senator MUSKIE. Senator Miller?

Senator MILLER. This 1,100 billion gallons per day, is that above the surface, or on the surface of the land, and also beneath the surface of the land?

Dr. WOLLMAN. You should address that question, really, to a member of the Geological Survey. I can give you their answer as I understand it.

It is this:

It accounts for the movement of water underground that appears somewhere or other as surface flow in the stream, and that, in general, U.S. Geological Survey conceives of ground water as a form of storage of surface water that, sooner or later, appears as surface flow. This measure excludes ground water reservoirs that are not now subject to recharge, or that are not now discharging through any surface stream. It excludes also any water that may escape underground into the sea, and, therefore, not be intercepted by a surface stream.

It is my understanding that this amount of water that is excluded is relatively small, compared to the figure that I have used.

Senator MUSKIE. Proceed, Doctor.

Dr. WOLLMAN. Now