601 LAKE SUPERIOR SUMMARY urging the protection of the water supply, Reviewing the progress made around to take care of the needs of the situation. Active work, however, is still required Lake Michigan, in brief, a very healthy both along the Indiana shore and the growth of public opinion is found favornorthern shore of Illinois on the water ing a supply of good potable water which and sewage problem. In Wisconsin and has led to the treatment of sewage and Michigan further attention will undoubt- purification of water in many conmuniedly be given towards improving existing -ties. Millions of dollars have been spent, the greater amount in the communities of conditions. In cases where sewage must be dis- Milwaukee and Chicago. Further excharged into a water supply, the problem penditures are necessary to solve the requires a program of watchful waiting, problem. The smaller communities have inasmuch as the growth of the community also been active. At present the most frequently extends the pollution to a needed attention seems to be in the Calupoint where both sewage treatment and met region in Indiana, the North Shore purification of the water require further of Illinois around Waukegan and at cerattention. tain local points in Wisconsin like Racine. LAKE SUPERIOR GEORGE H. FERGUSON, FELLOW A.P.H.A. Dominion Department of Health, Ottawa, Ontario, Canada THE RESIDENTS of the United The sewage from 10 of these municiStates and Canada possess, in the palities receives partial or nearly comsplendid immensity of the series of water- plete treatment before being discharged. ways through which so much of their CITY POPULATION common boundary passes, a heritage of Aurora .............................. 2,809 Biwabik ............................. 2,024 inestimable value. Millions of people McKinley .395 Gilbert .3,510 dwell in their watersheds. Along the Virginia . 14,022 .............................. 7,205 banks of the rivers and Great Lakes Eveleth Mt. Iron ............................... 1,546 . Kinney 1,200 ............................. communities which a few years since Buhl ................................ 2,007 ............................. 9,039 were mere villages are now, in popula- Chisholm Hibbing ..........................-. 15,089 1,879 ............................. tion and in social and industrial develop- Kewadin Nashwauk.. 2,414 . ment, among the most important on the Colquet 5,127 ...... ...................... continenit. Cariton Proctor There are only two municipalities operating sewerage systems, located in Minnesota which discharge untreated sewage into Lake Superior. These are Duluth with a population of 98,917 and Two Harbors with 4,546. Sixteen cities and villages, having sewerage systems, are located on the St. Louis River watershed which drains into Lake Superior at Duluth. These are listed opposite. Sanitary surveys which have been conducted by the Division of Sanitation of the Minnesota State Department of Health in co6peration with the city of Duluth have indicated quite definitely that the pollution due to the sewage from the city of Duluth and that which is carried in by the waters of the St. Louis River is confined to a relatively small area in the vicinity of the city of Duluth. . . .............................. 700 2,378 602 AMERICAN JOURNAL OF PUBLIC HEALTH The condition of the lake in the immediate vicinity of Duluth is 'not satisfactory from a sanitary point of view, and it would appear that the city of Duluth should take steps in the near future toward the installation of the necessary sewage treatment works. The pollution of Lake Superior at Two Harbors is confined almost entirely to the bay into which the sewage is discharged. The water supply for the city of Two Harbors is obtained from Lake Superior through an intake in another bay which is separated by a point of land from the bay into which the sewage is discharged. This water supply is investigated at regular intervals and it is seldom that the bacteriological determinations indicate the presence of organisms of the B. coli group in the untreated city water at the water works pumping station. There are no other sewerage systems which discharge sewage into Lake Superior in Minnesota, that are known to the state health authorities. Beginning in January, 1926, the Michigan Department of Health instituted a program of conferences with the various municipalities and industries for the purpose of discussing with them stream pollution problems. As a result of these conferences, numerous orders were issued to municipalities and industrial concerns to start on a program of waste elimination from the streams. During Julv these conferences were held in the Upper Peninsula and investigations showed that the pollution problems incruded the following: *Mine Wastes-Bessemer, Wakefield, Marquette, Escanaba, Ironwood and Stambough Paper Mill Wastes-Ontonagon, Manistique, Munising, Menominee and Escanaba Tannery Wastes-Sault Ste. Marie Chemical Plant Wastes-Newberry, Marquette, Sault Ste. Marie, Escanaba Sugar Factory Wastes-Menominee, together with municipal sewage at most of the cities and villages of fair size On account of the Upper Peninsula being sparsely settled and on account of the streams flowing long distances to the Great Lakes after pollution enters them, very few of these sources of pollution are serious as far as the Great Lakes are concerned and the effect upon the streams is somewhat limited. The only two places where industrial waste pollution is serious are at Marquette, where chemical wastes sometimes produce tastes in the municipal water supply, and at the Newberry Chemical Plant on the Tahquemenon River. It is a long distance by river from Newberry to Lake Superior and it is doubtful if this pollution has a very marked effect upon the water of the lake. In accordance with the program orders will be issued on a number of these industrial concerns and to the following municipalities: Ironwood, Bessemer, Iron River, Ishpeming, Negaunee, Marquette, Crystal Falls, Iron Mountain, Stambaugh, Kingsford, Munising, Newberry, Sault Ste. Marie, Manistique, and Menominee. Industrial orders will probably go to the tanneries, paper mills, chemical plants, gas plants and sugar factories. The paper mill companies state that they are already making arrangements to install machinery for the recovery of fiber as a logical business improvement. They emphasize the fact that they are doing this of their own free will. However, when this subject was first brought to the attention of the paper mill people in the fall of 1922, there was intense objection to any change in their habits. After a little investigation they found that the recovery of valuable constituents of the wastes interested them in a business way and they have been far more willing to co6perate in this problem on that account. There are only three municipalities of any importance on the Canadian shores of Lake Superior waters: Fort William and Port Arthur on Thunder Bay, and Sault Ste. Marie, Ontario, the latter being really situated on the upper waters of the St. Marys River. None of these municipalities treat their sewage, disposal of sewage being as stated in Table II. 603 LAKE SUPERIOR TABLE I TYPHOID FEVER DEATH RATE PER 100,000 POPULATION IN CITIES IN THE LAKE SUPERIOR REGION Name of City :0) S._ Year .0 .2 4x.d v Is 0I bo r. ._ .0 a En 1900....................... 1901....................... 1902............... 1903 1904....................... 1905.- 19056........................ 1907........... 1906..... 1908............. 1909....................... 1910....................... 1911....................... 1912....................... 1913....................... 1914....................... 1915....................... 1916....................... 1917....................... 1918....................... 1919....................... 1920....................... 1921....................... 1922........... 1923 ............ 1924....................... 1925....................... 61.7 48.6 65 52.8 49.2 42.9 38.5 49.5 39.9 73.4 23 24 26 21 11 9 7 4 2 6 3 1 3 1 3 116 50 33 50 34 30 94 26 15 30 84 33 19 14 20 16 17 11 15 S 2.5 5 10 2.5 S 0 0 *Cs ii 116 323 83 80 81 55 57 26 35 53 0 8.9 26 0 44 As it is necessary to have legislative authority before anything definite can be accomplished along the lines of the subject of this paper a short resume of legislation bearing on the question may be in order. In this connection it should be stated that by the terms of the British North America Act, jurisdiction over the navigable waters of Canada is vested exclusively in the federal government at. Ottawa. Among the statutes that have been enacted by the federal government of Canada is one known as the " Navigable Waters Protection Act." Under the provisions of this statute, no structure can be erected in navigable waters unless sanctioned and approved of by the Dominion Government and under which also mill owners and others are prohibited* from allowing slabs, sawdust, or other matter which might obstruct navigation, or pollute the waters, to be deposited in navigable waters. When any municipality proposes to build a sewer having its discharge into the navigable waters of Canada an official application with a description of the site and plans must be 0 0 89 19 58 19 38 37 36 72 44 53 96 94 110 33 17 33 40 40 32 7.9 0 0 7.7 0 7.7 . 0 44 41 0 63 32 0 363 0 51 23 0 22 0 0 0 *0 0 0 cn 133 83 172 116 52 68 59 ,16 73 56 24 54 23 22 29 7 7 28 7 24 0 8.3 16.5 0 0 V. N uQ 4.. CI)q .0 0 0 410 _: co 1911 siii 191 liii 106 68 90 83 35 33 30 21 22 9 0 0 5. 5 4 4 4 0 0 121 163 146 5 18 20 0 0 26 6 0 0 0 0 154 280 85 127 84 24 31 46 26 5 14 0 0 0 0 0 filed with the federal government at Ottawa, for approval of the said site and plans, and for permission to construct the outlet sewer. It is also provided that the Attorney-General of Canada may take proceedings to restrain the pollution of navigable waters. The Public Health Act of the Province of Ontario provides for action that may be taken in regard to the pollution of springs, wells, ponds, lakes, streams or rivers used as a source of a public water supply. TYPHOID FEVER Table I gives the statistics of death fro,m typhoid fever in the cities and towns therein mentioned for the period from 1900 onwards. These figures include both residents and non-residents and were compiled from the local health office records. As a matt-er of fact, according to the local records, over 40 per cent of Duluth's typhoid was imported from outside that municipality. Duluth does not suffer alone in this regard, other cities and towns on Lake Superior have numbers of miners and lumberman, etc., brought into their hospitals for treatment. AMERICAN JOURNAL OF PUBLIC HEALTH 644 TABLE II SEWAGE DISPOSAL DATA OF CITIES IN THE LAKE SUPERIOR REGION Water Supply Sewage DiSposal A_ Population , , Discharged Name of City 1920 Source Treatment Installed Treatment Installed Into Duluth...... None 1916 Lake Superior 98,917 Lake Superior Chlorination y . . 39,671 Lake Superior Chlorination & Superior Cit Sand Filtration 1900-20 None ....... Lake Superior Ashland .... ...11,334 Lake Superior Chlorination & Sand FiltraNone tion 1918 ....... Lake Superior None Lake Superior 1911 Marquette.. 12,718 Lake Superior Chlorination None 1913 Lake Superior Munising ... ....... 5,037 Lake Superior Chlorination None 1918 St. Mary Rivet Sault Ste. M arie, Mich. ...... 12,096 St. Mary River Chlorination None Fort Williair ......... None 23,500 Loch Lamond ...... 1908 Neebing and Kaministiquia Rivers 17,021 Lake Superior Chlorination 1903 None Lake Superior Port Arthur.......... None St. Mary River 22,000 St. Mary River Chlorination 1894 Sault Ste. Marie, Ont.. WATER SUPPLY AND __ .... ....... ......... ....... ....... ....... Table II is self explanatory. It will be seen that there has been a decided improvement in the record since the investigation of the International Joint Commission of 1913, in consequence of the greater effcrts that have been made to protect municipal water supplies. Notwithstanding the general improvement, outbreaks of typhoid have occurred, and the potential danger must be guarded against, owing to the pollution of definite portions of these waters and the limita-. tions, and at times inefficient operation of water purification plants. THE ACCURACY OF BACTERIAL COUNTS FROM MILK* ROBERT S. BREED, PH.D., FELLOW A.P.H.A. Chief in Research, Division of Bacteriology, New York State Agricultural College Experiment Station, Geneva, New York THE QUESTION of the accuracy of bacterial counts from milk has been given considerable attention in the investigational work at the New York Agricultural Experiment Station. The term "count" in this connection is an unfortunate misnomer. No one has ever actually counted the number -of bacteria in a cubic centimeter of milk in the same way that the number of people in a room can be counted. Various means exist for "estimating" the number of bacteria in a cubic centimeter of milk. Because estimates are not actual counts, some knowledge of the accuracy of the results secured is essential. The chief obstacles in the way of making these esti* Read before the Laboratory Section of the American Public Health Association, at the Fifty-fifth Annual Meeting at Buffalo, N. Y., October 12, 1926. per cent accurate arise from the fact that bacteria are exceedingly small objects and may occur in enormous numbers. Inasmuch as exact counts cannot be made, how can the accuracy of the estimates be determined? This must be done indirectly by comparing the results secured by one method with those secured by another. In one set of comparative results reported from the New York State Experiment Station some years ago' samples of milk containing the colon bacterium were prepared in such a way that the final counts were expected to be in the ratio of 1 :2:4. These samples were then analyzed both by the plate method and by the microscopic method by six analysts in two laboratories. Samples of this type were mates 100