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LETTER OF TRANSMITTAL.

THE INTERNATIONAL JOINT COMMISSION.

GENTLEMEN: I have the honor to present a report upon investigations made under my direction relative to remedial measures for the present conditions of pollution of certain boundary waters.

Respectfully,

EARLE B. PHELPS, Consulting Sanitary Engineer.

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SCOPE AND PURPOSE OF THE PRESENT

REPORT.

These investigations were undertaken in order to secure data upon which to base a report upon the second branch of the following reference:

1. To what extent and by what causes and in what localities have the boundary waters between the United States and Canada been polluted so as to be injurious to the public health and unfit for domestic or other uses?

2. In what way or manner, whether by the construction and operation of suitable drainage canals or plants at convenient points or otherwise, is it possible and advisable to remedy or prevent the pollution of these waters, and by what means or arrangement can the proper construction or operation of remedial or preventive works, or a system or method of rendering these waters sanitary and suitable for domestic and other uses be best secured and maintained in order to insure the adequate protection and development of all interests involved on both sides of the boundary, and to fulfill the obligations undertaken in Article IV of the waterways treaty of January 11, 1909, between the United States and Great Britain, in which it is agreed that the waters therein defined as boundary waters and waters flowing across the boundary shall not be polluted on either side to the injury of health or property on the other? Stripped of its explanatory matter the reference in question becomes:

In what way is it possible and advisable to remedy or prevent the pollution of these waters, on either side, to the injury of health or property on the other?

Satisfactory recommendations upon the advisability of remedial measures must be based on the one hand, upon the results of a thorough examination of existing conditions of pollution; upon the feasibility and cost of remedying these conditions wholly or in part; and upon a careful comparison of the relative value and cost of the benefits to be derived thereby. On the other hand, such an inquiry must be guided in the present reference by the terms of the treaty that the boundary waters "shall not be polluted on either side to the injury of health or property on the other."

It is understood that the advisability of this requirement itself is not in question and that it would be without the scope of the present reference to consider the merits of alternative projects, such as new sources of water supply for the lower communities, which would not accomplish this specific requirement.

It will be necessary, therefore, in this discussion of the advisability of remedies, to review the results

already obtained and reported upon by the Commission relative to existing pollution of these waters and to examine these results with special reference to the nature and extent of any injury to health or property which may be attributed to pollution crossing the boundary.

Such a review involves the interpretation of bacteriological results in terms of injury and necessitates in turn a discussion of reasonable and permissible limits of pollution, the extent and character of pollution from natural drainage, the efficacy of water purification plants, and the effect upon the safe operation of such plants of increasing pollution loads. Upon these questions the Commission has had the advice of a board of consulting engineers, and the conclusions of this board will be incorporated in the present discussion. Upon the basis of these two lines of investigation-the bacteriological studies and the engineers' recommendations-it will be possible to formulate specific recommendations for a minimum requirement for the treatment of sewage entering the boundary waters. This requirement, however, will be expressed in terms of bacteria and organic improvement, and will still permit the application of alternative measures to obtain the desired results. There remains also the question of "possibility" of the required measures, which is interpreted in this case to mean the practical possibility or the feasibility of the projects, having due regard to the engineering phases and to reasonable limits of cost.

In order to determine in each individual case what specific treatment of the sewage will accomplish the desired result and the feasibility and advisability of the suggested treatment, it has been necessary to make extensive field and office studies of drainage and treatment plans in the more important cases. For the purpose of the present reference and report it was deemed advisable and sufficient to confine these detailed studies to the St. Clair, Detroit, and Niagara Rivers. Upon the latter two streams are situated the two largest cities existing along the boundary rivers, and these waters are accordingly by far the most seriously polluted. In these two cities the most important and difficult engineering problems are to be found. and will have to be solved. Feasible remedies developed in these two cases will therefore be feasible in

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the smaller communities, while the advisability of remedies in the case of the latter will necessarily depend upon the advisability of a general policy of improvement determined primarily by the conditions in the major cities upon which the burden of expense must fall.

The St. Clair River was included in the studies as a case of less serious pollution, It seemed desirable to include this stream within the Detroit district in order that the question of advisability of remedies might be discussed from all viewpoints. Representing as it does the most polluted of those streams which will not, under the broad terms of the reference, require immediate treatment, this river serves as a useful illustration of a case where the strictly local aspects of the situation demand more stringent treatment than would be justified by the results to be attained from an international viewpoint.

These studies have been of the nature of preliminary engineering investigations of certain alternative projects of main drainage lines and treatment works. They have in each case been carried sufficiently far as to detail of basic data and of design to justify preliminary engineering estimates of cost and a general statement of feasibility. While these studies have been thorough, they are for the most part based upon existing field data and upon office study and compilation of available material. There has been no attempt to make them comprehensive, nor has it been deemed necessary or advisable to develop the projects recommended in sufficient detail to justify their adoption without further engineering studies. A single feasible solution, selected in each case from a few alternative projects, has been adopted as being sufficient to demonstrate the feasibility of the general policy. Further studies based upon the data of special field work may readily develop more economical drainage lines, while progress in sewage treatment will almost certainly indicate further economies in that direction. In particular, no study has been made of the possibilities of treating sewage by aeration, a new and undeveloped method now in the experimental stage, but holding promise of future possibilities.

In brief, the engineering studies have developed feasible plans of collection and disposal at all important points on the three most seriously polluted connecting rivers and have determined the upper limits of cost of these improvements with a degree of precision that will be best appreciated by reference to the detailed reports upon the work by the district engineers in charge.

Finally, the present discussion and report brings together the data from these various lines of inquiry and formulates a reply to the second branch of the reference. This reply is in the form of a proposed policy expressed in terms sufficiently broad and general to be applicable to the international boundary

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waters as a whole at the present time and in the future, and at the same time so detailed and concrete as to indicate definitely the present requirements in specific cases.

The reference also calls for an inquiry as to the best arrangement for the operation and maintenance of the remedial works. The administrative control of pollution in the boundary waters is obviously a Federal rather than a State or Provincial matter. The magnitude of the work, the diverse jurisdictions involved, and the necessity for international cooperation and uniform development upon the two sides of the boundary emphasize this fact. The proper administrative supervision of any international policy for the protection of these waters demands periodical examinations of the waters and of the remedial works. The administrative body must have authority to enforce the established policy as to present requirements, increasing requirements with growth of population, and the inclusion of other streams within the scope of the policy at such times as the increased population upon those streams may determine.

Such an administrative body must be international in character, and it should be a continuing body with a reasonably fixed policy and procedure. As the matters involved are primarily health matters and in no way affect navigation or property interest other than through the health of the people, the Federal health authorities of the two Governments would quite naturally and logically constitute, or nominate, the joint administrative body for the direct enforcement of the continuing policy of stream protection.

EXTENT AND SEASONAL DISTRIBUTION OF POLLUTION AS DISCLOSED IN THE PROGRESS REPORT.1

GENERAL.

The bacteriological investigations were begun in April and continued through October, 1913. Individual stations were under observation for consecutive periods of from 14 days to 3 months. Bacteriological examinations alone were made and results are reported showing the numbers of bacteria growing at 20° C. and at 37° C. and the numbers of B. coli, a characteristic intestinal organism. Upon the basis of these results certain conclusions relative to the pollution of the waters were made. In certain portions of the Great Lakes and in all the connecting waterways serious pollution was shown to exist, although the great body of lake water itself is for the most part remarkably pure. Both maximum and average results for the periods of observation at each station are reported, and attention is directed to the diver

1 Progress Report of the International Joint Commission, in re The Pollution of Boundary Waters, including the report of the sanitary experts. Jan. 16, 1914.

gence of daily results from the average as indicating intermittency of pollution. Maximum results are frequently 10 times as great as short-period averages, a point of significance in any discussion of water supply.

SEASONAL VARIATION.

Careful analysis of the results discloses another kind of variation, the consideration of which leads to important deductions. This is the seasonal variation.

Studies that have been made in the past of the pollution and self-purification of streams have indicated a direct dependence of self-purification upon the temperature of the water. At points somewhat remote in terms of time from the point of pollution the streams show less residual pollution at the higher temperatures and a maximum condition of pollution during the winter months.

In the case of the boundary rivers, the time of passage is relatively short, so that no evidence of material improvement from self-purification need be expected. A quite unexpected and hitherto unnoted phenomenon has, however, been shown in this case, namely, a great increase in the bacterial evidence of pollution in the warmer months. This effect is shown so consistently in the work of the several laboratories, and upon the various rivers, that there can be no doubt of its reality. It is hardly to be believed that there is actual multiplication of the intestinal organism in the streams themselves, although this possibility can not, with our present knowledge, be entirely eliminated. It is more probable that the bacterial content of the sewage shows a seasonal variation. Whether this be traceable to actual multiplication of intestinal bacteria within the sewers or to a greater per capita discharge of these organisms in the warmer months can not be stated. In either case the observed result is of immediate and direct significance. The presence of the organism B. coli is in the case in hand directly and quantitatively indicative of human pollution. The known characteristics of the organism justify the belief that its reaction to environmental conditions is not unlike that of true pathogenic or disease producing bacteria, especially the typhoid germ. In the absence of contrary evidence, therefore, the B. coli from sewage is universally accepted as a quantitative measure of dangerous pollution, and whether the observed summer increase in numbers of this test organism be attributed to increased proliferation within or without the body, the accepted significance is in no sense altered.

The quantitative extent of this seasonal variation is of immediate interest in any study of the effect of pollution upon water supplies. The data of the Progress Report available for this purpose have accordingly been brought together for analysis. These data include the results of all examinations made at the

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Investigations upon the Detroit River by Hubbell in 1915 gave results strikingly similar in general form, but showing a less decided drop in the fall months.

For comparison with these results there is given in Table II a summary of the results of water examination at Buffalo during the years 1906-1914, inclusive. Daily examinations of 1 cubic centimeter samples were made. The table gives the total number of positive tests recorded during this period. There is also included a summary of total deaths from typhoid fever in Buffalo during the same period. The information contained in this table is taken from the annual reports of the Buffalo board of health.

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