THE WATER SUPPLY OF CHICAGO: ITS SOURCE AND SANITARY ASPECTS. BY ARTHUR R. REYNOLDS, M. D. COMMISSIONER OF HEALTH 'OF CHICAGO, AND ALLEN HAZEN S. B. CHEMIST, WATER DEPARTMENT, WORLD’S COLUMBIAN EXPOSITION. Reprinted from The Chicago Medical Recorder, December, i8gj. PRESS OF The McCluer Printing Company, 53 DEARBORN ST., CHICAGO. THE WATER SUPPLY OF CHICAGO: ITS SOURCE AND SANITARY ASPECTS. By ARTHUR R. REYNOLDS, M. D. COMMISSIONER OF HEALTH, OF CHICAGO, AND ALLEN HAZEN, S. B., CHEMIST, WATER DEPARTMENT, WORLD’S COLUMBIAN EXPOSITION. Chicago receives its water supply from Lake Michigan through tunnels at four different points, Lake View, Chicago Avenue, Fourteenth and Sixty-eighth Streets, varying from one to four miles in length. Within a few months, extensions now in course of construction at Lake View on the north, and Hyde Park on the south, will be completed, and no water will be received in the city from a source nearer than two miles from the shore. The first tunnel constructed was at Chicago Avenue, was five feet in diameter, and completed March 25, 1867. A seven-foot tunnel parallel to the first was completed July 12, 1874, each two- miles in length, to an intake common to both. The Hyde Park tunnel, seven feet in diameter and extending one mile, was completed July 22, 1885, and has been the only source of supply at that point since. The Lake View tunnel, six feet in diameter and extending one mile into the lake, was completed April 5, 1892. The four-mile tunnel at Fourteenth Street was completed De- cember 8, 1892. It consists of two tunnels, each six feet in diameter, extending two miles to join an eight-foot tunnel ex- tending to the four-mile crib. The capacities of the tunnels in twenty-four hours are as fol- lows : Chicago Avenue 130,000,000 gallons. Sixty-eighth Street 72,000,000 “ Lake View ■ 72,000,000 Fourteenth Street 140,000,000 “ Total 414,000,000 2 From the Chicago Avenue works to the Twenty-second Street pumping station, there is a tunnel seven feet in diameter and four miles in length, passing under the Chicago River and the South branch, which is intersected at Harrison street works by a seven- foot tunnel from the Fourteenth Street works. The water is pumped into the mains by twenty-six engines, as follows : 6 pumps at Chicago Avenue, with a capacity of 96,000,000 gallons. 9 “ at Sixty-eighth Street, “ “ 77,000,000 “ 2 “ at Twenty-second St., West Side, ‘ 60.000,000 “ 3 “ at Fourteenth Street,with a capacity 54,000,000 “ 2 “ at Central Station, Harrison Street, 36 000,000 “ 4 “ at Lake View, with a capacity of 30,500,000 “ Total 353,500,000 “ The water from the Lake View works supplies Lake View, Twenty-fifth and Twenty-sixth wards, and part of Jefferson, the Twenty-seventh ward. Hyde Park works supply Hyde Park and Town of Lake, wards Twenty.nine to Thirty-four. The old city is supplied from Chicago Avenue and Fourteenth Street, with a main leading from Four- teenth Sreet tunneled under the river to the Town of Lake, wards Twenty-nine, Thirty, Thirty-one. All, however, are so constructed that the water from Lake View may supply Hyde Park, and vice versa. Before the construction of the Fourteenth Street and Lake View tunnels, Lake View was supplied by water taken from the lake through several iron pipes laid upon the bottom of the lake, and extending from 1,400 to 2,000 feet into the lake about fifty feet apart. With the great growth of the city, the Chicago Avenue tunnels were not sufficient to furnish water for the Harrison and Twenty- second Street pumping works, so that some six years ago a short additional tunnel was extended 3,000 feet at Chicago Avenue for fire emergencies, which at various times during those years, par- ticularly in 1892, was in use in common with the two-mile tunnel, but now permanently closed. From Belmont Avenue north, sewers empty into the lake every half mile. The largest of these is at St. Lawrence Avenue, one- half mile to the north of the Lake View pumping station. 3 On the South side, at Twenty-second Street, Thirty-fifth,Forty- third, Fifty first,Fifty-sixth, and Seventy-first Streets, sewers empty into the lake, while all other sewers empty into the river. During times of freshet there is a current in the river to the lake, which, of course, carries sewage with it, consequently water taken from the shore intake at Chicago Avenue must be more or less polluted with sewage. The same will apply to the old intake through the iron pipes at Lake View. From the junction of Fullerton Avenue and the North branch of the river there is a tunnel extending to the lake through which water is pumped into the North branch, and which has a capacity of 14*7,750,000 gallons per twenty-four hours, and is used to flush that branch of the river when required. At the junction of the South branch of the Chicago River and the Illinois & Michigan Canal there is a pumping station which pumps water from the South branch into the Illinois & Michigan Canal, which conducts it south to the Illinois River, and ultimately to the Mississippi River. These works are now pumping 407,936,- 000 gallons per twenty four hours, and the capacity will soon be in- creased. These pumping works,except in times of heavy rainfall, will, because of the sluggish character of the Chicago River, produce a decided current in it from the lake toward the pumps, so that it is only in times of freshet that the Chicago River flows into the lake. The extensions of the various tunnels within the past two years have undoubtedly secured for the city a water less liable to sewage pollution than was formerly obtained. The available anal- yses of the water are perhaps inadequate to accurately measure the improvement, but fortunately we can apply that most satisfactory of all water tests, the typhoid fever death rate test. The improvements in the water intakes have not all been made at a single date, but if we compare the two years ending Sep- tember 30, 1892, and September 30, 1893, we find that during the earlier year the shore intakes at both Lake View and Chicago Avenue were in common use, while the four-mile tunnel was not yet opened, while for the greater part of the later year the shore inlets were entirely closed and the four-mile tunnel at Fourteenth Street and the one-mile tunnel at Lake View were in use. The improvement in the death rate from typhoid fever with these changes in the water supply is well shown by the following 4 table of the rates in the various wards of the city and in public in- stitutions for the two years: TABLE SHOWING DEATHS FROM ALL CAUSES AND FROM TYPHOID FEVER BY WARDS FOR TWO YEARS ENDING SEPT. 30, 1892, AND SEPT. 30, 1893. WARD. Year Ending Sept. 30, 1892. Year Ending Sept. 30, 1893. Deaths from all causes. Deaths from typhoid fe- ver. Per cent of deaths from typhoid fe- ver. Deaths from all causes. Deaths from typhoid fe- ver. Per cent of deaths from typhoid fe- ver. 1 329 9 2.73 320 4 1.25 2 439 20 4.56 451 9 2.00 3 498 34 6.83 483 9 1.86 4 424 20 4.72 437 10 2.29 5 967 79 8.17 843 20 2.37 6 1,133 73 6.44 1,136 36 3.17 7 712 43 6.04 680 19 2.79 8 682 32 4.69 682 13 1.91 9 912 56 6.14 850 26 3.06 10 1,019 60 5.89 1,180 34 2.88 11 587 37 6.30 494 16 3.24 12 863 59 6.84 966 21 2.17 13 704 43 6.11 686 23 3.36 14 868 62 7.14 880 23 2.61 15 960 73 7.60 995 25 2.51 16 1,306 97 7.43 1,187 24 2.02 17 594 43 7.24 438 8 1.83 18 413 20 4.83 375 8 2.13 19 969 40 4.13 931 11 1.18 20 457 42 9.19 392 13 3.32 21 546 38 6.96 511 13 2.54 22 614 40 6.51 523 13 2.48 23 831 68 8.18 657 16 2.43 24 369 28 7.59 332 6 1.81 25 418 24 5.74 423 11 2.60 26 710 38 5.35 654 19 2.90 27 188 12 6 38 226 7 3.10 28 257 8 3.52 230 4 1.74 29 629 24 3.81 704 16 2.27 30 1,168 52 4.46 1,441 34 2.36 31 439 23 5.24 597 11 1.84 32 464 25 5.39 507 12 2.37 33 621 33 5.31 832 22 2.64 34 632 35 5.55 670 23 3.43 Pub. Inst’s. 2,404 400 16.64 2,331 153 6.56 Cor. cases.. 1,550 1,933 Total for 1 entire city. 26,646 1,790 6.72 26,977 712 2.64 . The total number of deaths by months since 1890 are shown by the following table: 5 TABLE SHOWING DEATHS FROM TYPHOID FEVER IN CHICAGO BY MONTHS. 1890 1891 1892 1893 January 53 67 311 41 February 136 61 187 30 March 103 71 76 41 April 45 136 56 58 May 32 408 70 56 June 107 167 55 60 July 86 200 211 55 August 115 182 179 76 September 95 198 138 86 October 72 171 92 November 67 150 67 December 47 186 47 Total 1,008 1,997 1,489 503 It is most unfortunate for this comparison that the old sup- plies were partially in use during the first two months of the latter year before the four-mile tunnel was opened, and we may believe that if this had not been the case, the comparison would have been still more favorable to the improved supply. It is a well-known fact that people using a water supply to which they are not accustomed, are often more susceptible to any infection which it many contain than are those using such water regularly. A striking illustration of this was furnished by Phila- delphia in the Centennial year when the typhoid death rate was nearly doubled, while in Chicago, the present year, for the first five months of the World’s Fair period, the rate has been less than half as high as for the corresponding months of the preceding year, and for the entire years under consideration; in spite of the vast numbers of visitors continually present in Chicago there has been a reduction of over sixty per cent in the percentage rate. The mortality percentages from typhoid fever for the two years as given above, have been put upon two maps of the city, showing the water intake and sewer outlets in use for the respec- tive years. See maps on pages 376-377. The reduction in the death rate from typhoid fever in one year of over sixty per cent is most striking, and it can hardly be doubted that the improvements in the water supply have been the chief, if not the only cause in this gratifying reduction. It is to be noted particularly that there is no very marked local distribution of the disease. In the earlier year there was not a ward in the city without an excessive rate. The so-called best wards suffered almost equally with the poorer wards, and the wards on the lake shore were not more favored than those along 6 the Chicago River. The only general difference to be observed was that those wards supplied with water from the Hyde Park SANITARY MAP Or Cliicag'o for year ending Sept. 30, 1892 Showing Water Intakes Sevier Outlets, and Per Centage of Deaths from Typhoid Fever, to Total Number of Deaths from All Causes in each Ward. Scale of Jfe/eo. Mortality Per Centages from 'TYPHOID TEVEH . Chicago 6.72 Philadelphia, /69/, 2.93 Boston. J69J. 1.4-6 Paris. 169/, J.OJ Mew York. J69J, .66 Brooklyn . JQ9J. .66 JLondon. /QOJ. .61 Berlin . 169/. 30 intake, had somewhat lower rates than the rest of the city, and during the past year, with the improved condition of the other in- takes, this difference has disappeared. 7 As there is no marked local distribution of the typhoid fever, so there were no exceptions to the general improvement with bet- SANITARY MAP OF Chicago for Year ending Sept. 30, 1893. Showing Water Intakes. Sewer Outlets, and Percentage of Deaths from Typhoid Fever, to Total Number of Deaths from All Causes. In each Ward. Scale of Afiles. Atoreality Per Centages from TYPHOID FEVER. Chicago 2.60 Philadelphia. 1692, 2.22 Boston, 1892. 1.22 Paris. 1692, 1.40 New York. 1892. .90 Brooklyn, 1892, .80 Bond on. 1892, .49 Berlin , 1892, .42 ter water supply. There was not a single ward in the city which did not show a substantial reduction, although as might be ex- 8 pected with such a complex problem the percentages in the differ- ent wards varied somewhat. The lessons of the maps may be summed up as showing a general cause of the typhoid fever in the city only slightly affected by local conditions, and a general improvement in the death rate with improved water supply without any local exceptions what- ever. Stronger evidence could hardly be produced even if addi- tional proof was required to show the causal relation between the contamination of the water supply and the typhoid fever. The mortality percentages from typhoid fever in a number of cities for the last year for which we have the data were as follows : Year ending Sep- tember 30. Deaths from all causes. Deaths from ty- phoid fever. Mortality percent- age from typhoid fever. Chicago 1892 20,646 1,790 6.72 Chicago 1893 27,977 712 2 64 Philadelphia 1892 24,305 539 2,22 Boston 1892 11,236 137 1.22 Paris 1891 54,443 549 1 01 New York 1892 44,317 399 .90 Brooklyn 1892 20,857 167 .80 London 1892 86,355 424 .49 Berlin 1892 32,696 137 .42 The cities having the lowest typhoid fever death rates given above, London and Berlin, use only filtered water. London draws nearly all of its water for some four or five millions of people from the two grossly polluted rivers, the Thames and the Lee, and after filtering it, supplies it to a population that is almost free from typhoid fever. Among the improvements which will eventually still farther protect the purity of Chicago’s water supply may be mentioned the drainage canal. After its completion with the construction of a complete system of intercepting sewers along the entire lake front, the sewage will be turned from the lake to the Mississippi River. In the meantime it may be a question worth considering by the engineers whether filtration would not be as cheap and effective a means of improving the supply as the farther extension of the tunnels. City Hall.