127261 MAR 18 1909 SXB ·STI ·3 6701892 · PREFACE TO THE SECOND EDITION. The first edition of this book was exhausted sometime since and numerous calls have been made for another edition. The book has been entirely re-written and much new matter has been added. An effort has been made to facilitate computations by Kutter's formula and tables of the value of ʼn have been added to assist in a proper determination of its value for sewers. The question of Sewage Disposal has also received attention. PREFACE TO THE FIRST EDITION. The subject of the sewerage of towns is attracting much more attention now than formerly. The reason for this is evident. While the country was new and the towns small and sparsely built, the disposal of the liquid wastes and other refuse was left to be provided for by each householder as he might deem best. Various plans were employed, most of which were objectionable, and, in many cases, no plan at all. But as the towns increase in size and are more compactly built the question of a proper system of Sewerage forces itself upon the attention of the people. Some general system must be adopted for the whole town and the question is, what system? The moderate cost of the "Separate System" makes it possible to carry out a system of sewerage in many cases where the expense of the "Combined System" would make the construction of sewers impossible. One hindrance to the rapid introduction of the Separate System has been the lack of available information concerning it. Much has been written on the subject, but the necessary information is scattered in numerous pamphlets, reports and papers presented to scientific societies in the United States and in England. The object of this book is to explain what the Separate System is, what it is designed to do, and to give practical directions for designing and constructing sewers in accordance with that system. No single design, however complete in all its details, will be best adapted to every case. Each town will present some features peculiar to itself and the general plan must be modified to suit the conditions of each case. All that is here attempted is to give sufficient theory, data and results of experience to guide in properly designing and constructing sewers on the Separate System. CONTENTS. Need of Sewerage.-Pollution of Streams.-Pollution of the Roof Water.-Size and Material.-Flushing.-Ventilation.- Sewage Disposal.-Storm Water.-The Preliminary Survey.— |