1. Extended Curve Method of Forecasting Population... 14. Outfall Sewer Crossing Valley on Hydraulic Gradient. 15. Sewer in Hollow Wall above Street Level. . . . . . 6. New Orleans Pumping Station Superstructure.. 7. Profile and Plan of Sewer.. 18. Rod for Sounding for Rock. 19. Machine for Sounding for Rock. 20. Alignment of Sewer Junctions... 6. Population per Acre in Boston, by Wards.. 7. Persons per Family and per Dwelling in 1900 and 1910. 8. Average Sizes of Families, 1850 to 1910... 9. Records of Some Severe Storms. . . . . 10. Rainfall During Five-minute Periods of Excessive Precipitation.. 11. Velocity and Discharge in Sewers 4 to 36 ins. Diameter... 12. Velocity and Discharge in Sewers 33 to 120 ins. Diameter. 15. Materials Moved by Water Flowing at Different Velocities.. 16. Sizes Required at Minimum Grade..... 17. List Prices, Weights and Dimensions of Vitrified Sewer-pipe. 19. Cost of Laying Sewer-pipe... 20. Cost of Manholes.... 21. Amount of Excremental Organic Matter in Sewage. SEWERAGE PART I. SEWERAGE SYSTEMS CHAPTER I GENERAL OUTLINE OF SUBJECT ARTICLE 1. PRINCIPLES AND DEFINITIONS EVERY Community produces waste matters that must be disposed of in some way. These are generally classified as garbage, ashes, rubbish, and sewage. Sewage is the liquid waste of a community. It is of three general classes: Domestic sewage, which is the water-borne excrement, washing and dish water, and other dirty water from places of human residence, business buildings or institutions; industrial sewage, which is the liquid wastes from various manufacturing and industrial processes; and storm sewage, or the water flowing off of street surfaces, adjacent land, and roofs during rain storms. The two first named are commonly combined for removal and called house sewage.* The removal of sewage from the residences and centers of industry of a community is demanded on two grounds: The higher one of public health and the more popular one of convenience. In designing a system, each of these must be kept constantly in mind, the former being always given predominance if they conflict in any way. Some call this "sanitary" sewage-to the author's thinking an absurd misnomer. The term "house sewage" has been adopted as a standard by the American Society of Municipal Improvements. |