Mr. DONDERO. Then it becomes a question of time, current, and flow.

Dr. HOSKINS. More a question of time because time is the predominant factor in natural purification. There is a very direct relationship between time of flow of water in a stream and the rate and percent of purification or the percent of bacteriological reduction.

The CHAIRMAN. Does chlorination destroy all the disease germs in water?

Dr. HOSKINS. Chlorination is only partially effective where water is turbid or where the chlorine will react with organic substances in the water other than bacteria. Chlorine is by no means dependable in treating a turbid water. It is very much more efficient in treating clear water from which organic material has been largely removed.

Mrs. HONEYMAN. May I ask, in speaking of human consumption, are cities the size of Cincinnati dependent on river water for their supply of drinking water mostly?

Mr. HOSKINS. It is generally the only source that they have. The large concentrations or urban population ordinarily have no other source of supply than surface sources, streams or lakes. There are no underground sources capable of supplying large concentrations of urban population.

The CHAIRMAN. They put in their purification processes before consumption.

Mr. HOSKINS. Yes; but there is a limit, as Dr. Parran told you, to the extent that the water purification plant can operate efficiently just as there is a limiting load on a bridge or a limiting load of traffic on a highway. Just so there is a limiting load that the purification plant can handle and produce safe drinking water. The only way to overcome that limiting load is to magnify or intensify the processes of purification, and these additional processes are naturally expensive. Mr. SMITH. Have you a break-down in the cost?

Mr. HOSKINS. No. I think the gentleman following me will produce those figures as he has concrete figures of the Cincinnati plant. Mr. DONDERO. Take the Ohio River. Which contributes more to pollution, industry or the natural sewage from the municipalities on that stream?

Mr. HOSKINS. That point was gone into quite thoroughly in the original study of the Ohio River in 1913 to 1916. A personal survey was made of practically every industry and community on the watershed and the nature and extent of the industrial wastes pollution determined as well as that resulting from the domestic population. It was found at that time, when industry was quite active, that the ratio of industrial pollution to domestic sewage pollution was one and onefourth to one (1.25 to 1.0). This did not include pollution from acid mine waste, only the organic pollution.

Mr. DONDERO. What would be the pollution direct from industry? Mr. HOSKINS. Paper mills, breweries, tanneries, and industries of that nature.

The CHAIRMAN. Take the Youngstown district, does that add much to the pollution?

Mr. HOSKINS. The Youngstown district is on the Mahoning River. The CHAIRMAN. And it runs into the Beaver and then into the Ohio?

Mr. HOSKINS. That waste is largely from the steel mills. It comes into the Ohio River through the Beaver River.

The CHAIRMAN. Yes, sir.

Mr. HOSKINS. By the time that pollution has reached the Ohio it is quite well dissipated, although the Beaver itself is seriously polluted, of

course.

The CHAIRMAN. That is also the case with the Pittsburgh district. It is dissipated before it gets there.

Mr. HOSKINS. In times of exceedingly low water it is. But in times of high water, when the time of flow is short, there is a very considerable contribution of pollution from Pittsburgh present in the river water at Cincinnati.

The CHAIRMAN. If there be such a large quantity of water it is well diluted.

Mr. HOSKINS. Not always, because during the longer period of flow when the velocity of the water is low a considerable amount of pollution settles to the bottom of the stream in the pools then when we have a high water those pools are flushed out. Strange as it may seem, our most intense pollution at Cincinnati is not in times of low water at the Cincinnati intake above the city, but in times of moderate or high

water.

The CHAIRMAN. Because the pollution has settled on the river bed and is carried out.

Mr. HOSKINS. Flushed out; yes, sir.

The CHAIRMAN. And the dams are let down in high water and scour out.

Mr. HOSKINS. Yes, sir. The dams when raised form sedimentation pools which decrease the velocity and the times of flow from point to point and thereby provide increased purification.

I have here a résumé of stream pollution conditions in the Cincinnati metropolitan area indicating among other things that the pollution in times of low flow is so intensified in the Cincinnati pool that all the dissolved oxygen in the water at the lower end of Cincinnati is used up. This results in the production of obnoxious odors above Fernbank Dam and below Cincinnati and also kills considerable fish. These noxious conditions have been frequently known to occur. I will introduce this into the record.

The CHAIRMAN. Yes.

(The résumé referred to is as follows:)

RÉSUMÉ OF STREAM-POLLUTION CONDITIONS

CINCINNATI METROPOLITAN AREA

The Cincinnati metropolitan area has a population of about 800,000 persons, of whom some 30 percent reside outside of the corporation limits of the city. Included in the area are the cities of Covington and Newport, Ky., and a numer of smaller communities.

As part of the metropolitan area is situated in Ohio and part in Kentucky, the solution of the local stream-pollution problem is one not only for joint intercity action, but calls also for interstate coopera

tion.

The Ohio River is already a polluted stream when it reaches the eastern edge of the metropolitan area at dam 36 (mile 461 below Pitts

burgh). As all of the cities of the Cincinnati area mentioned in the preceding paragraphs of necessity obtain their public water supplies from the Ohio River, the pollution load reaching their waterworks intakes is of vital importance to these municipalities.

The estimated total population of the Ohio River drainage basin above these waterworks intakes is about 8,200,000 people and is about equally divided between urban and rural population.

In 1930 the population from which sewage was discharged to the Ohio River and its tributaries above these waterworks intakes at Cincinnati was estimated to be 3,200,000 persons, the sewage from 2,900,000 of whom was discharged to the rivers without any treatment whatsoever. The sewage from a population of only about 300,000 located on tributaries received any kind of treatment, none of these sewage-treatment plants being located on the main stream. In other words, the sewage discharged to the Ohio River above Cincinnati was practically all untreated or unpurified.

This condition results in the imposition of an extremely heavy burden of bacterial and organic pollution on the water-purificationplant processes. The water-treatment plants are reaching the stage where the capacities of the known water-purification methods are in danger of being seriously overburdened.

The bacterial analyses of the raw water supplied to the Cincinnati municipal intake indicate that the bacterial content of organisms of the coli-aerogenes group, used to estimate the bacterial-pollution load for raw water supplied to filtration plants, is frequently close to the limit of average tolerability of not more than 5,000 B. coli per 100 cc, which studies of the Public Health Service indicate to be about the average maximum consistent with the production of a safe filtered and chlorinated water, when considered over a considerable period of time. In addition, there have been several instances in recent years when the monthly average has approached 20,000 B. coli per 100 cc which, according to the Public Health Service studies, cannot be safely incurred more than 5 percent of the time. Similarly, the daily bacterial load at times exceeds 100,000 B. coli per cc. To obtain additional protection as far as possible from this state of affairs, Cincinnati is now engaged in a $3,000,000 program of extensions to the water-filtration plant, but there are limits to what can be done to offset the increasing pollution burden.

Work of the Public Health Service has furnished data for the following table showing the percentage contribution of the upstream population groups to the pollution load at several Ohio River waterworks intakes:

It should be noted that a large part of the pollution at each point originates in wastes discharged within the first 200 miles upstream. As is demonstrated by these figures, Wheeling suffers from the sewage pollution of Pittsburgh, East Liverpool, and Steubenville; Portsmouth is heavily burdened by the pollution of Huntington, Áshland, and Ironton.. În like manner, Cincinnati receives the effects of the pollution from the group of cities just mentioned; and last, but not least, the Louisville water-filtration plant is burdened with the pollution load from the Cincinnati area.

This effect has been summarized in a recent article by Sanitary Engineer H. W. Streeter, United States Public Health Service, entitled, "Stream Pollution Surveys", published in Civil Engineering, Volume 7, No. 1, January, 1937, which reads as follows:

1. Under both summer and winter conditions of temperature and flow, a very large proportion of the total bacterial pollution of the river at the various water intakes probably originates in wastes discharged within zones of 200 river-miles or thereabouts above these intakes.

2. Pollution originating at more distant points upstream is a considerably larger factor in the condition on the river at these intakes during the winter than in summer, though it appears to be outweighed at all times by pollution from more immediate sources.

3. Acid wastes in the upper river do not appear to exert much influence on the bacterial condition of the river at Portsmouth or further downstream but are a powerful factor near Pittsburgh, where in the absence of sewage treatment the present acid condition of the river undoubtedly has prevented an intolerable overburdening of water-purification systems through bacterial pollution.

In conclusion, it might be stated that these conditions cannot go on forever; that there will be a breaking-down point similar or worse than the great wave of intestinal disturbances down the Ohio Valley in the fall of 1930 after the drought of that year; and that a coordinated effort of the cities involved is necessary for the remedial correction of the situation.

The CHAIRMAN. How far above Cincinnati is the intake of the water supply?

Mr. HOSKINS. About 8 miles.

The CHAIRMAN. Where is the sewage returned to the river?

Mr. HOSKINS. All along the waterfront. Part of the return is made from tributaries of the Ohio. The Little Miami, discharging only a short distance, a mile and a half below Cincinnati water intake is one. At times under the definite conditions of the stream flow a flushing out of the Little Miami occurs and some of the water has been known to flow upstream in the Ohio to the Cincinnati intake. That has been definitely proven by the Ohio State Health Department.

The CHAIRMAN. Many years ago you had a flow of water in Walnut Hill up there. Do you have that flow of water there now?

Mr. HOSKINS. There is a reservoir on Walnut Hill. It is the largest storage of purified water. Mr. Hibbs of the Cincinnati Water Department can elaborate on that.

This map will show you the location of the Cincinnati waterworks intake; the mouth of the Little Miami River, which carries a part of the Cincinnati sewage coming in just a little distance below; the points where pollution enters along the river front, shown in the shaded areas in the circles; and the location of Dam 37, which forms the Cincinnati pool, near the left-hand side of the picture.

The CHAIRMAN. How far apart are the two dams, 36 and 37 in miles?

Mr. HOSKINS. About 20 miles. I will submit this map for the record.

The CHAIRMAN. Yes.

(The map referred to is filed with the committee as an exhibit.)

Mr. HOSKINS. I have also a memorandum discussing in somewhat more detail the pollution in Cincinnati pool, which I will introduce into the record.

The CHAIRMAN. Yes.

(The paper referred to is as follows:)

SUMMARY OF OHIO RIVER SEWAGE POLLUTION WITH REFERENCE TO THE CINCINNATI POOL

The Cincinnati pool is created by dam no. 37, located at approximately the westerly limits of the city of Cincinnati and is at mile 483 below Pittsburgh. The pool extends upstream about 20 miles to dam 36 (461 miles below Pittsburgh) to about the eastern limits of the city, the business district being about equidistant from the two dams.

The sewage of a metropolitan population of about 800,000 people, a little less than 200,000 of whom are in Kentucky, is discharged without treatment into this pool. The public water supplies of both Cincinnati and the Kentucky cities of Covington and Newport are obtained from the upper end of the pool below dam 36.

The quantity of water in the Cincinnati pool, at the time of zero velocity in low-water stage with a navigation channel of 9 feet is estimated to be about 16,000,000,000 gallons. The 800,000 persons residing in the area, discharge about 160,000,000 gallons of liquid wastes into the pool daily. The ratio of sewage discharged daily to water in the pool at such times is 1: 100.

Stated differently, this would mean that at times of low water, if there were no additional water coming down the river, no rainfall or evaporation, the water in the pool would be nothing but undiluted sewage after a period of about 3 months.

Actually, to prevent nuisance conditions from developing in streams a dilution of the sewage by river water at the rate of from 4 to 6 cubic feet of water per second per 1,000 of contributing population is desirable. This means that for the sewage discharged into the Cincinnati pool, a river flow of at least 4,800 cubic feet per second is needed at all times to prevent nuisance conditions from developing in the river at Cincinnati itself.