to know how much warmer it is. Essentially this downstream temperature is governed by three factors. In fact, there may be some arguments on a rather middling basis as to whether these figures would be exact. Of course, they wouldn't be, it is too complicated for that, but nevertheless it has become the practice to use the figures arrived at by the method I am going to present as an index of what would happen downstream, and especially in August your temperatures downstream would be very close to this. This temperature downstream is determined by three factors. One, the amount of heat injected per given time. Two, the flow of the river, that is, its volume per given time. And, three, the temperature upstream. On a whole, whether you have recirculation or not doesn't make any difference in the downstream-well, it is part of the mechanism, the low flow inevitably occurs so you get double passage through the condenser but you can calculate this without any reference of the amount taken through the condensers. We know the amount of heat injected, that is specified in the application. Daily flow records go way back to 1902. Temperature records are quite inadequate. There is some information, a 10-year sampling program by the board of health in Minnesota, and in this 10-year period, however, for the critical months of August, there were only two temperatures taken. These were 77° and 82°. In this 10-year period there were 310 August days, there were only 2 samplings taken on these 310 days, and these 2 samplings were not even representative because it happened that those Augusts were Augusts of record flow, the highest flow on record. And yet that 82° appears in the Northern States Power Co.'s summary data sheet as the maximum temperature in a 10-year survey, random sampling by the State board of health, the maximum of two temperatures out of 310 days. Furthermore, these were not samples of the water in question because they were taken from the Stillwater Bridge by dipping out samplings of about a foot below the surface, you see, it wasn't for this purpose this work was done, and measuring the temperature, you don't get the temperature of the river that way. You have to traverse with the thermoting stick on down into the water, get an average calculation cost, an average calculation for anything you can call temperature of the river. The company proposes to take the water from the river, not up by the bridge where these samples were taken, but below the sewage outflow, where you have quite different water indeed, biologically and from a sanitary viewpoint, possibly from a temperature viewpoint. You will also note there were no storm sewers in Stillwater and at times of heavy rainfall a bypass of raw sewage can occur. Our information about urban temperatures is quite inadequate. And also other factors about water quality that depend on this survey are likewise inadequate for the same reasons. If the company has anticipated a plant at Oak Park Heights for 20 years, it should have been gathering data during this time, if they were really concerned about the welfare of the public, because this is vital data to know what the effects of the plant will be. You don't get this from an ouija board. However, this deficiency of data does not prevent calculation of the temperature rise. We can calculate how much the temperature is increased without reference to the temperature upstream, and this figure has some importance because it gives us an idea of the magnitude of the increase in the first place, and then if at some time in the future we would have figures on upstream temperatures, all we would have to do is to add them all and we would have our downstream temperature. To predict what might happen in the future we have to look to the past records, and we can apply these formula and these data to the past records of the riverflow and come up with an answer to what would have been the temperature rises at times in the past. Then we can expect somewhat the same sort of thing to happen in the future. If this plant had been on the river since 1902, and we focus our attention on the months of August, a rise of more than 5° would have occurred on 42 percent of these months. This is the whole river downstream, not just below the condensers. As an example of what would happen during a particular month of August, I took August 1936there are charts for this on a submitted report-and for the first 15 days the temperature rise was more than 10° and averaged 10° for about 6 more days and then fell somewhat. Since fish must live through each day, these figures are significant. Smallmouth bass and walleyed pike are valued game fish in the St. Croix. Their need for cool water should be considered. Carp are an undesirable species and thrive in warm water. Moderate temperature changes can make considerable change here, as Mr. Mertes mentioned. I won't go over that again, except I will mention one thing. It promotes the growth of blue-green algae, an obnoxious growth of no use to fish life, and the company will use chlorine to get rid of this blue-green algae from the condensers and canals. Otherwise they choke them up and lower their efficiency by obstructing heat transfer. There has been mention of heat dissipation. I don't want to impose upon the time too much, but the heat loss would have to take place through the surface. In August, the heat is passing into the river from the air. This is evident from the fact that your surface water is somewhat warmer than a few feet down, and if this is occurring, it couldn't, of course, be passing in the other direction. It wouldn't until the temperature of the river has been raised to something like the temperature of a stagnant upshaded pond in August. This is an equilibrium with the area, see. Springs and tributaries would dilute the water downstream, but not restore normal temperature. Consider again the mixing zones. The importance of mixing is indicated by a report on a 265,000-kilowatt plant on the Delaware River. After this plant was in operation, mixing was such a problem that two jetties had to be built. After that they rerouted the effluent to discharge above rapids instead of below. After that they built two more jetties. You see, mixing was quite a problem there. They considered the placid slow waters of the St. Croix with this river, the Delaware River, that they were dealing with there. More data about the river at Oak Park Heights should be available soon from the Public Health Service surveys which Mr. Mertes mentioned, and a model is being run at the University of Minnesota, under the auspices of Northern States, to study mixing. The results should be available soon. Again we must ask, "Wouldn't it have been better to enlighten decisions with investigations made earlier instead of after decisions have been made and hopes raised for tax windfalls and real estate windfalls?" When all the data is in and the predictions are made and argued, a good solution depends on what the people want and need. The magnitude of protest against this proposed plant location shows very clearly what the people want. They want clean rivers, clean air, unspoiled natural areas. The people of this country have built the greatest farming and industrial system in the history of man. They spoiled many rivers and natural resources and they didn't much care where there seemed to be so many rivers and unboundless natural resources. But now, when food and industrial goods are plentiful for most of us, and could be plentiful for all so far as productivity capacity is concerned, when we make millions of boats and fishing rods, from water skis to swimming suits, we need the few good rivers left. The men whose talents have brought this boon of time of plenty have licked this matter of production. They have become so expert that they can continue without spoiling natural resources. Now let the decisions rest, not only on the cost of the electricity and pennies for kilowatt-hours, let's rule out the spoilage of good rivers at the price of electric power. [Applause.] Senator METCALF. Just a minute. What would you estimate would be the average number of kilowatts used in the home per month? Mr. PEMBLE. My wife takes the readings. Maybe 800 to a thousand, I would say. There must be people here who read their meters. We read our own and it is around that. Senator METCALF. Say there were a thousand kilowatts, it would cost a dime a month for a consumer to cool this water, wouldn't it? Mr. PEMBLE. Well, yes. Senator METCALF. It would raise the average light bill a dime a month. Mr. PEMBLE. If you did this on all the plants, but, of course, this is just part of the system. Senator METCALF. But if it costs, and from my experience with the utilities, they base their rates on their highest costs, so they would probably raise it a dime a month. This was the question that I was going into with Mr. Ewald yesterday. We have an area here that provides recreation, not only for the people of St. Croix and Washington County, but for the people of St. Paul and Minneapolis. We have an area that will probably provide, as you pointed out, electric power for that same group of people. It is going to send this power back into St. Paul or Minneapolis or some other area, at least larger than the immediate vicinity. So we have to weigh the two considerations, it would seem to me it would be worth a dime a month to the people of the area to have a recreational resource. [Applause.] Please. Mr. PEMBLE. We are touching here about planning, you are talking planning now. We can indicate planning, the planners, the profes sionals should get at the job and do it, if it means calling in the Metropolitan Planning Commission or call in a bigger planning commission, if necessary. Some kind of overall planning must inevitably come to the whole country. But we can only indicate by these examples the need and value of such planning, we can't take on the job, of course, but it is something that should be done. Senator METCALF. Now, you were a little bit critical about the figures on temperature because there were only two samples taken in 10 years. Mr. PEMBLE. Yes. Senator METCALF. Would you tell us how many samples were taken for you to determine average flow of the river? Mr. PEMBLE. In 10 years? Senator METCALF. In the month of August? Senator METCALF. You made 31? Mr. PEMBLE. No, we didn't make them. These readings of flow come from the Geological Surveyor Record. Senator METCALF. Are they daily readings? Mr. PEMBLE. Yes. They take readings at the St. Croix Falls and mouth of the Apple River, and by adding the two you get pretty close to the flow of water at Stillwater. Senator METCALF. Instead of two flows of 10 years, you have a daily sample to ascertain the average flow? Mr. PEMBLE. That is right. I think Mr. Mertes has more information on that than I do, but this is a matter of record. Senator METCALF. Thank you very much for your testimony, Mr. Pemble. (The full text of Mr. Pemble's statement follows:) AN ANALYSIS OF HEAT REJECTION TO THE ST. CROIX (By Carl A. Pemble, president, Save the St. Croix, Inc.; chemical engineer; 20-year valley resident; appointed in May 1964 by St. Croix River Association to investigate possible effect of proposed NSP plant) Senator Nelson, members of the Senate committee, participants, and those who came to listen. Thank you for this help in solving our problem. Many of you are long-time champions of conservation. Had your counsel been heeded in the past, this problem might have been solved in a more satisfactory manner. It is unfortunate that the extent of concern by so many for conservation and for the St. Croix River is manifested only now after the future of the river has been placed in doubt. Perhaps too many of us believed that the best things in life are free until we learned that our right to clean air and clean cool water must be defended. However, we are not engaged in a fight but in the resolution of a problem about the use of natural resources. To this project we bring our different needs, values, and opinions. And here again we see that a lot of trouble could have been avoided had the opinions of all been considered much sooner. Instead there has been and still is stubborn resistance to regional planning. Some people, beyond differing with the values we place on the river, say they can see no cause for concern about water and air pollution. Very well, we shall submit facts and figures to show that there is cause for concern. You know, people have stood up at meetings to say, "Give us the facts, but don't bother us with figures. Your numbers are too big and scary." But there's no avoiding the numbers. I hope you see clearly just how big and scary they are. THE PROPOSED PLANT In regard to heating the river, we shall consider just the first unit, because only unit No. 1 is covered by the application now pending with the Minnesota Water Pollution Control Commission. The second unit would be larger, more than doubling the pertinent figures that follow. The expected maximum capability of unit No. 1 is 600,000 kilowatts' more than twice the peak load of the city of St. Paul. Not that this power is for St. Paul; the generating capacity within the city is already double the peak load.❜ Boiler capacity is rated at 240 tons of coal per hour.' This is 5,760 tons per hour or 2 million tons per year, twice the coal burned in St. Paul, Minneapolis, and adjacent suburbs in the year 1958.3 This proposed plant being the most efficient in the system would run at full capacity as much as possible. The difference between load and capacity of the system would ease the load on less efficient plants.* The power of the coal burned would amount to about 11⁄2 million kilowatts. Only about two-fifths of this would leave the plant as electric power. A like amount is carried by the exhaust steam to the condensers where the heat is dumped by the condensing steam which returns to the boilers as water for another cycle. This waste heat is at too low a temperature to be useful for power. Disposal is a serious problem. One method is to circulate water from the coolant side of the condensers through huge trickle towers where cooling occurs by contact with the air and by evaporation. The use of such towers would cost about $500,000 per year more than would cooling the condensers with the river.' Considering the size of the operation, this is not too costly-on the order of a cent for 100 kilowatt-hours. The Northern States Power Co. proposes to dump the waste heat into the St. Croix River, and has applied for permit specifying a maximum heat rejection of 2,520 million B.t.u. per hour. EFFECTS OF HEATING THE RIVER There are two obvious facts that indicate need to study the potential effects of dumping this heat into the river. The first is that it is an enormous amount of heat, equivalent to 2,000 tons of coal burned per day. It is the heat output of 20,000 home furnaces going full blast, about 10 times the heat from all the home furnaces in Stillwater, full on. The second obvious fact is that the St. Croix is a small river as far as flow is concerned. This is quite apparent above Stillwater. At Stillwater, it becomes broader and deeper, forming Lake St. Croix. A maximum of 660 cubic feet of water per second would be taken from below the Stillwater sewage disposal outfall and conducted through a canal to the condensers where it would be heated a maximum of 17° Fahrenheit. The heated water would flow 1,000 feet to the bay and discharge into the river above the present site of the Bayport swimming beach. Here the heated water would mix with the river forming what is called the "mixing zone," the boundaries of which vary with flow and other factors. Within the mixing zone, temperatures would range from the downstream "mixed river" temperature to 17° above the upstream normal temperature. At times the flow through the condensers would exceed the flow of the river, in which case recirculation would occur increasing overall temperature rise to more than 17°. As flow decreases, the situation approaches that of lagoon cooling. In this complicated system, there is one parameter that is easily calculated. It is the temperature that would result from the rapid and complete mixing of the flow of heat and the flow of the river. For convenience, we will call this the "mixed river temperature." It can be calculated from the rate of heat rejection and the temperature and flow of the river just upstream. By making such calculations, using recorded values of past flow and temperature, we can learn what to expect in the future. Daily flow has been recorded since 1902, but temperature records are inadequate. There is some information in the records of the water sampling program by the State board of health, covering the past 10 years, but only two samplings were in the critical month of August. Moreover, these months happened to be months of abnormal flow, the highest of record for August. The temperatures 1 Northern States Power summary data sheet. 2 Statement by Mr. Earl Ewald, president of Northern States Power Co., Aug. 10, 1964. 3 "An Appraisal of Air Pollution in Minnesota"-Minnesota Department of Health, 1961. Refers to a project by Sanford Research Institute. Statement by Mr. Hibbard Hill, vice president in charge of engineering, Northern States Power Co.. at water pollution control commission meeting on Aug. 21, 1964. 5 Aug. 27, 1953, and Aug. 3, 1955-see "Surface Water Supply of the United States," by U.S. Geological Survey. |