n the preceding pages has been presented the procof reasoning followed in the derivation of Table in which is embodied the gist of this report. s statement has involved a description of physical ditions and an outline of the general problem, toher with an analysis of the economics of different hods of solution, leading to the conclusion that sewage of Buffalo can best be treated at three -s, namely, at Niagara Street near Cornelius eek, on Squaw Island, and at Tifft Street near pkins. For collection, such decision involves the ension of the Swan Street sewer to Squaw Island, dification and relief of the upper portion of Swan reet system, together with comprehensive intercepn for the South Buffalo area. The detailed study of these collections has followed an analysis of the water consumption in an effort to build up sewage-flow units, and has in turn been supplemented with estimates of the cost of treating sewage by clarification and disinfection. The conclusion reached is that the city of Buffalo can most successfully and most economically remedy the boundary water pollution for which it is responsible by sewage-treatment processes involving a destruction of pathogenic bacteria of not less than 93 per cent, together with a 50 to 60 per cent removal of solid matter in suspension. Such treatment could be installed in works of modern type at a cost not to exceed $3,600,000, and would require for material and labor in operation the yearly sum of about $203,500. In short, Buffalo can adequately treat its sewage by the construction and operation of Imhoff tanks and disinfecting works, at a total yearly cost of some $391,000. ACKNOWLEDGMENT. It is desired to acknowledge in general the aid and cooperation of city officials in providing the engineers of the Commission with working quarters, and with free access to city records. In particular to Mr. George H. Norton, city engineer, and to his assistants in the bureau of engineering, is due appreciation for their courteous interest and support in furtherance of these studies. DESCRIPTION. TONAWANDA, N. Y. The city of Tonawanda is riparian to the Niagara River, being located about 7 miles north of the city of Buffalo. Along its northern boundary is situated Tonawanda Creek, which stream is a county line separating this city from the neighboring municipality of North Tonawanda. The general topography and geology is that prevalent south of the escarpment. The development of Tonawanda is centered, as regards both population and industry, in the northern central quarter, with residential sections spreading out to the south and west. The industries are not numerous, a former important lumber transshipping business being now restricted to North Tonawanda. POPULATION. The past population growth of Tonawanda is shown in Table 151. The figures, representing both National and State returns, have been projected to a future population of 15,000 as the basis for design of collectors. This growth, spread over a period of 35 years, represents an annual increase of 162, and is equivalent to a decennial increase of 17.4 per cent for the first decade and 12.1 per cent for the last decade. The population figure selected for treatment studies has been interpolated between the limits given to a value of 11,500. WATER SUPPLY. The water supply for Tonawanda is derived from Niagara River through an intake located close to the Grand Island side of Tonawanda Channel. The water is untreated and during 1914 was consumed at the gross average rate of 5.44 million gallons daily, equivalent to a per capita daily consumption of 583 gallons. There is no doubt but that much of the gross pumpage is lost through remnants of old wooden mains; moreover, the figures given are open to the suspicion of not including sufficient allowance for slip. Study of the meter records of large consumers reveals the fact that of the total, 1.5 million gallons daily is used by one industrial concern-a paper mill-which discharges its wastes direct to the river. Further industrial use of water is limited to 0.37 million gallons daily. DRAINAGE. The total drainage of Tonawanda is now discharged through two combined sewers which have outlet at the foot of Bouck Street and of Franklin Street, respectively. A further development of the territory in the southern portion of the town will probably lead to the construction of a third outlet which, in so far as its exact location is of interest to this report, may be tentatively placed in Rogers Street. Owing to the flat slopes which prevail in this locality, it is necessary to resort to pumping in order to conduct the inland drainage to the river, although this could be largely avoided were the discharge of sewage to Tonawanda Creek permissible. The fact that neither this 11,500 town nor the neighboring city of North Tonawanda has utilized this creek for sewage discharge purposes is sufficiently notable for record. Future. Popula 15,000 SITES FOR TREATMENT. It would appear desirable, were it economic, to com bine sewage treatment for the two Tonawandas at one central site, but any apparent advantage disappears upon analysis. The center of North Tonawanda drainage is located in the vicinity of Wheatfield Street, while Tonawanda discharges the bulk of its sewage at Bouck Street. The distance between these two points by direct shore line is about 6,500 feet, |