this afternoon, the opponents tomorrow morning, and rebuttal on Friday afternoon.

I think we would go on endlessly here if we start having an audience cross-examination. But if you wish to submit some questions, I would have no objection.

Judge MCDONOUGH. I have but one question.

Senator NELSON. If everybody has one, then we are done.

Judge MCDONOUGH. I don't believe I am in a position of being everyone; I am in a position of being of the proponents.

Senator NELSON. If you would like to submit any questions, I will see to it that Government witnesses submit answers, and submit it for the record. I think if anybody here is entitled to ask a question of any witness, everybody should be, and if we opened it up, I have been in enough of these affairs to know that we would never conclude it. If you will submit your question, we will see to it that it is answered.

Mr. THUET. I am Paul Thuet, for the opponents. I agree with the thinking, but would we be given the right to submit questions on the same basis?

Senator NELSON. As I stated earlier, we wish every viewpoint to be heard. We will make every attempt for equal opportunity for every viewpoint. If anybody wishes to submit any questions to a witness, we are perfectly glad to submit them to that witness for an answer. If someone wishes to submit a statement himself explaining or in rebuttal, we will put that in the record as long as the material isn't repetitious. Every attempt will be made here for everybody to be fairly heard, but I know if we opened it up to questions on crossexaminations from the audience it will never be completed. I think it is perfectly fair if everyone has a chance to write down his questions and submit them, just so it is done and prepared for the record by the 18th. I am sure the Government witnesses would be happy to respond to questions after the 18th, although it wouldn't be printed in the record.

Senator Metcalf.

Senator METCALF. Thank you, Mr. Chairman.

I am in complete accord with these procedures that have been set up. Either side should have an opportunity to present its testimony, but cross-examination, as in a legal matter, is not conducive to this type of a hearing.

Mr. Stein, you are the chief enforcement officer. In determining when you are going to set up an enforcement conference and so forth, do you have standards fixed by legislation?

Mr. STEIN. No; we do not, sir.

Senator METCALF. Under the provision of S. 649 there were standards established?

Mr. STEIN. That would have authorized standards to be established; yes, sir.

Senator METCALF. Yes. When you bring an abatement action or prepare an abatement action, you said you had to find health or welfare passage?

Mr. STEIN. The words are "endangerment to health or welfare." Senator METCALF. I am going to leave one question to the next witness. But Senator Nelson suggested that perhaps this proposed plant would develop barge traffic that would disrupt pleasure boating

on the river. Do you conceive that that would come under the jurisdiction of your agency as a ground for abatement ?

Mr. STEIN. No, sir. I think what we would do is only concern ourselves with the conditions of the water quality on the river. I don't think we deal with the question of boat safety. If barge traffic or other activities would affect water quality, we would certainly be concerned. The only thing that we deal with is water quality. We are a specialty agency.

Senator METCALF. Water quality as respecting endangerment to health?

Mr. STEIN. Health or welfare.

Senator METCALF. If the water quality endangered pleasure fishing, you would consider that welfare?

Mr. STEIN. Yes, sir; yes, sir; we do.

Senator METCALF. And if the water quality was such that it endangered fishing or other body activity with the water, that would also be welfare?

Mr. STEIN. Yes, sir; right.

Senator METCALF. But you have not authority to go into these enforcement procedures in anticipation that such a pollution will occur?

Mr. STEIN. That is correct, sir. We can only deal with an existing discharge, not an anticipated one.

Senator METCALF. And you have to wait until there has been this endangerment to health or welfare?

Mr. STEIN. That is correct, sir.

Senator METCALF. If you went into court to prove a case of abatement, you would have to prove endangerment to health and welfare? Mr. STEIN. That is correct, sir.

Senator METCALF. There are no legislative standards?

Mr. STEIN. No, sir.

Senator METCALF. I think that is all. Thank you very much, Mr. Stein.

Senator NELSON. Thank you, Mr. Stein.

We will now call on Dr. Tarzwell, chief, Aquatic Biology Section, Basic and Applied Sciences Branch of the Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio, Division of Water Supply and Pollution Control.

It is a pleasure, Doctor, to bring you before us.

STATEMENT OF CLARENCE M. TARZWELL, CHIEF, AQUATIC BIOLOGY SECTION, BASIC AND APPLIED SCIENCES BRANCH, ROBERT A. TAFT SANITARY ENGINEERING CENTER, DIVISION OF WATER SUPPLY AND POLLUTION CONTROL, PUBLIC HEALTH SERVICE

Dr. TARZWELL. Thank you, Senator.

Although aquatic biologists and fishery workers have for a long time recognized the great importance of temperature in the aquatic environment, it has been only in recent years that high water temperatures have become important as a water pollutant. It is not generally appreciated that merely raising the temperature of a clean water can constitute pollution. However, excessively raising the temperature

of a stream, lake, or reservoir is pollution just as much as depleting the oxygen or adding toxic materials because it interferes with, lessens, or destroys a desired beneficial use; namely, the production of sport and food fishes and other aquatic organisms.

We have seen gradual slight rises in water temperatures, which alone seemed unimportant at the time, finally destroy a large portion of the trout water in this country. Deforestation and agricultural activities in Michigan and in several other States have rendered many trout waters unsuited for trout largely through bringing about higher water temperatures. Temperature is a governing factor in determining if a stream will be a trout stream. Further, average temperatures may mean very little because it is the extremes which are governing. If temperatures in a trout stream were raised to lethal levels on only 1 day in the year and then for only a few hours, its value as a trout water would be destroyed or severely impaired.

Increased water temperatures can influence fishes and other aquatic organisms both directly and indirectly and in a variety of ways.

1. Local high temperatures may produce a thermal block to migration.

2. Sudden changes in water temperature can be lethal to fishes and other aquatic organisms.

3. Temperature can act as a directive force to control migration by repelling or directing fish into certain paths or into certain areas. Some fish swim into hot water in which they are killed or in which they do not normally live even though they might as easily have swum into water which would have been harmless. Fish acclimated to warm water are rapidly killed when they swim into cold water.

4. Temperature may increase or decrease food production and food demand and it also influences spawning.

5. Temperature influences the composition of fish populations and the relative abundance of certain species. Usually, high temperatures favor the coarse and undesirable species in more northern waters.

6. High-water temperatures favor certain species of algae and may cause blooms, especially of the undesirable blue greens.

Optimum temperature for some diatoms, a microscopic algae of great importance in the food chain, range from about 64° F. to 86° F. However, many prefer much lower temperatures and some do not live above 50° F. The blue-green algae can withstand considerably higher temperatures and the optimum temperature for many of them range from 95° F. to 104° F. and they often become a nuisance in heated

waters.

It should be recognized that temperature do not have to reach lethal levels in order to render a water unfavorable for a given species of fish or even to eliminate that species. Temperature which favor competitors, predators, parasites, and disease can eliminate a species at levels far below those which are lethal. As water temperatures increase, bacterial action and the so-called natural purification process are speeded up. This may result in the depletion of oxygen during the summer in certain areas in which dissolved oxygen conditions are satisfactory at other times of the year.

Temperature seldom acts as an independent variable and generally its effects must be considered in combination with other environmental factors. Temperature and dissolved oxygen must be considered to

gether. Temperature influences the effects of carbon dioxide, hydrogen-ion concentration, and toxicants which may be in the water. Aquatic organisms are coldblooded and their metabolism is influenced by water temperatures. As the water temperature rises, fishes require more dissolved oxygen in order to maintain a normal existence or to live at all. The effects of temperature in fishes varies with age, size, and season and is especially important for spawning and the development of eggs and fry. Winter temperature for eggs of trout must be below 58° F. and for salmon should not be above 50° F. in the midwinter periods.

Fish become acclimated to high temperatures much more rapidly than they do to low temperatures. Thus, they can be killed in passing from warm to cold water in winter. High water temperatures, which are not harmful in summer, can be rapidly lethal in winter. While fish can be acclimated to higher temperature, there is a definite point beyond which they cannot go. When acclimated to high temperature, their resistance to low temperature is reduced.

Temperature acts through metabolism to control activity of fishes. As the temperature increases, the rate of metabolism necessary just to maintain the organism increases and the oxygen requirements increase. Thus, while a fish might survive at a given temperature by remaining inactive, forced activity would cause rapid death through oxygen deficiency. As the temperature rises, a point is soon reached where fish cannot be fully active even under conditions of oxygen saturation. Carbon dioxide also influences the oxygen requirements. Thus, if it is present in appreciable quantities, at higher temperatures, considerably more dissolved oxygen is required for fish activity and survival.

While fish may exist over a considerable range of temperature through remaining inactive and not feeding, temperature must be favorable if we are to produce a crop of desirable sport and food fishes. Water temperatures which may be resisted by adult fishes for long periods can be entirely unsuited for reproduction and the survival of the species. For example, temperature levels rapidly lethal for brook trout are 82° F. to 83° F. but for good production they should not exceed 73° F., and it is better if they do not exceed 68° F. In considering allowable temperature, it must be realized that there is a wide range between desirable temperatures and those which are rapidly lethal. Thank you, Senator Nelson, for allowing me to present this statement.

Senator NELSON. Thank you, Dr. Tarzwell.

Senator Metcalf, do you have any questions you wish to ask?

Senator METCALF. Yes.

Dr. Tarzwell, you said "excessively raising the temperature." What did you mean by that?

Dr. TARZWELL. Any excessive raising of temperature would be raising it to a level which produced an environment that was less suitable for those organisms you wish to produce. This is going to differ with different species. In other words, a temperature which would be excessive to trout would not necessarily be excessive for the warmwater fishes-the raising of a temperature to a point where environmental conditions become less favorable for these organisms which you wish to produce.

Senator METCALF. So you couldn't measure it, or you couldn't answer the question, in the terms of raising the temperature by a certain number of degrees-it would change in different streams?

Dr. TARZWELL. It would depend, sir, upon the original temperature in the stream and how much latitude you might have. It would depend on the species which were of importance in that stream.

Senator METCALF. If the temperature of the stream were raised to such an extent that it would destroy food fish that were used for commercial fisheries, would you recommend to Mr. Stein that an abatement procedure be brought?

Dr. TARZWELL. Generally speaking, sir, the raising of the temperature would not necessarily affect the food fishes; it would more likely affect the bottom organisms which are very important in the food chain. In many instances, the food fishes can withstand higher temperatures. There are exceptions. Some of the minnows cannot stand as high a temperature as the largemouth bass, which can probably stand higher temperatures than any of the other sport fishes, but you have to consider the whole environment. But if these temperatures would render it unfit for the reproduction for the eggs or fry, or would eliminate or decrease the food organisms, I would recommend-yesthat this pollution here exists, because it is interfering with this desired

use or resource.

Senator METCALF. That would be such a distraction that it would be violative of the welfare of the people?

Dr. TARZWELL. Yes, sir.

Senator METCALF. If it were just sport fishing, would you give the same answer?

Dr. TARZWELL. Yes, sir; because, from an economic standpoint, our sport fishes are worth more than our food fishes. It has been estimated that our sport fisheries in this country are worth between $2 and $3 billion annually. Our food fisheries produce, on the whole, including Alaska, about 5 million pounds a year. This is not of the same dollar value, but it does represent a very important high protein, high mineral, low-fat diet that we need now and perhaps we will need more in the future and would need our best efforts for the preservation.

Senator METCALF. As I came into town this morning, I notice several of those houses out on the river already-people who are preparing to do ice fishing for the rest of the winter.

If the temperatures of the stream were raised to such an extent that you couldn't move onto the river for ice fishing for a month or so, would you consider that was such a violation of the welfare that it would justify an abatement procedure?

Dr. TARZWELL. I began my fisheries career in Michigan. As you perhaps know, we have a great deal of ice fishing there. In fact, some of the species for which it is important that the harvesting be done in winter is northern pike and some of the others, and it does produce a valuable recreational resource. And if it interferes with it, it is not directly pollution, it is a side effect, but it does interfere with the harvesting of the crop-put it that way.

Senator METCALF. And you could do all those things that you suggested under the Federal law?

Dr. TARZWELL. This is out of my field of competence, sir, and I should not attempt to answer that as a scientist. I feel that Mr. Stein, who is in the legal phases, should answer that.