Sewerage and Sewage Treatment

=118. Elements.=—The principal elements in construction are: labor, materials, tools, and transportation. The lack of or inadequateness of any one of these detracts from the eff...

=68. Need.=—In the design of a sewerage system it is occasionally necessary to concentrate the sewage of a low-lying district at some convenient point from which it must be lift...

=283. Types.=—Automatic dosing devices are used to apply sewage to contact beds, trickling filters, and intermittent sand filters. These devices can be separated into two classe...

=90. Materials.=—The materials most commonly used for the manufacture of sewer pipe are vitrified clay and concrete. Cast iron, steel, and wood are also used, but only under spe...

=41. The Plan.=—Good practice demands that a comprehensive plan for a sewerage system be provided for the needs of a community for the entire extent of its probable future growt...

=255. Theory.=—The cycle through which the elements forming organic matter pass from life to death and back to life again has been described in Chapter XIII. It has been shown i...

=228. Purpose.=—The first step in the treatment of sewage is usually that of coarse screening in order to remove the larger particles of floating or suspended matter. Screens an...

=106. Importance of the Subject.=—Sewers may be constructed by day labor or by contract. Under the day labor plan a city official or commission is charged with the purchase of m...

=17. Dry weather Flow.=—Estimates of the quantity of sewage flow to be expected are ordinarily based on the population, the character of the district, the rate of water consumpt...

=55. General.=—The appurtenances to a sewerage system are those devices which, in addition to the pipes and conduits, are essential to or are of assistance in the operation of t...

=208. Physical Characteristics.=—Sewage is the spent water supply of a community containing the wastes from domestic, industrial, or commercial use, and such surface and ground...

=34. Principles.=—The hydraulics of sewers deals with the application of the laws of hydraulics to the flow of water through conduits and open channels. In so far as its hydraul...

=245. The Process.=—Septic action is a biological process caused by the activity of obligatory or facultative anaërobes as the result of which certain organic compounds are redu...

=265. The Process.=—In the treatment of sewage by the activated sludge process the sewage enters an _aëration tank_ after it has been screened and grit has been removed. As it e...

=99. Stresses in Buried Pipe.=—The stresses which sewer pipe should be designed to resist are: internal bursting pressure, for sewers flowing under pressure; stresses due to han...

=275. The Miles Acid Process.=—The Miles Acid Process for the treatment of sewage was devised and patented by G. W. Miles. It was tried experimentally at the Calf Pasture sewage...

=7. Division of Work.=—Engineering work on sewerage can be divided into four parts, namely: preliminary, design, construction and maintenance. An engineer may be engaged during...

=219. Definition.=—Disposal of sewage by dilution is the discharge of raw sewage or the effluent from a treatment plant into a body of water of sufficient size to prevent offens...

=198. Work Involved.=—The principal effort in maintaining sewers is to keep them clean and unobstructed. A sewerage system, although buried, cannot be forgotten as it will not c...

The method in use for cleaning a sewer by thrusting a fire hose down it can also be used for flushing sewers. It is an inexpensive and fairly satisfactory method. There is, howe...

=278. Methods of Disposal.=—Sludge is the deposited suspended matter which accumulates as the result of the sedimentation of sewage. The methods for the disposal of sludge as di...

=1. Sewerage and the Sanitary Engineer.=—Present day conceptions of sanitation are based on the scientific discoveries which have resulted so much in the increased comfort and s...

the bed to a depth of about 1 to 3 inches at one dose, and the siphon should discharge at a rate of about one second-foot for each 5,000 square feet of filter area. A dose shoul...

118. Elements. WORK OF THE ENGINEER. 119. Duties. 120. Inspection. 121. Interpretation of Contract. 122. Unexpected Situations. 123. Cost Data and Estimates. 124. Progress Repor...

68. Need. 69. Reliability. 70. Equipment. 71. The Building. 72. Capacity of Pumps. 73. Capacity of Receiving Well. 74. Types of Pumping Machinery. 75. Sizes and Descriptions of...

17. Dry Weather Flow. 18. Methods for Predicting Population. 19. Extent of Prediction. 20. Sources of Information on Population. 21. Density of Population. 22. Changes in Area....

228. Purpose. 229. Types of Screens. 230. Sizes of Openings. 231. Design of Fixed and Movable Screens. PLAIN SEDIMENTATION. 232. Theory of Sedimentation. 233. Types of Sedimenta...

41. The Plan. 42. Preliminary Map. 43. Layout of the Separate System. 44. Location and Numbering of Manholes. 45. Drainage Areas. 46. Quantity of Sewage. 47. Surface Profile. 48...

208. Physical Characteristics. 209. Chemical Composition. 210. Significance of Chemical Constituents. 211. Sewage Bacteria. 212. Organic Life in Sewage. 213. Decomposition of Se...

106. Importance of the Subject. 107. Scope of the Subject. 108. Types of Contracts. 109. The Agreement. 110. The Advertisement. 111. Information and Instructions for Bidders. 11...

245. The Process. 246. The Septic Tank. 247. Results of Septic Action. 248. Design of Septic Tanks. 249. Imhoff Tanks. 250. Design of Imhoff Tanks. 251. Imhoff Tank Results. 252...

99. Stresses in Buried Pipe. 100. Design of Steel Pipe. 101. Design of Wood Stave Pipe. 102. External Loads on Buried Pipe. 103. Stresses in Circular Ring. 104. Analysis of Sewe...

90. Materials. 91. Vitrified Clay Pipe. 92. Cement and Concrete Pipe. 93. Proportioning of Concrete. 94. Waterproofing of Concrete. 95. Mixing and Placing Concrete. 96. Sewer Br...

7. Division of Work. 8. Preliminary. 9. Estimate of cost. METHODS OF FINANCING. 10. Bond Issues. 11. Special Assessment. 12. General Taxation. 13. Private Capital. PRELIMINARY W...

219. Definition. 220. Conditions Required for Success. 221. Self-purification of Running Streams. 222. Self-purification of Lakes. 223. Dilution in Salt Water. 224. Quantity of...

255. Theory. 256. The Contact Bed. 257. The Trickling Filter. 258. Intermittent Sand Filter. 259. Cost of Filtration. IRRIGATION. 260. The Process. 261. Status. 262. Preparation...

198. Work Involved. 199. Causes of Troubles. 200. Inspection. 201. Repairs. 202. Cleaning of Sewers. 203. Flushing Sewers. 204. Cleaning Catch-basins. 205. Protection of Sewers....

265. The Process. 266. Composition. 267. Advantages and Disadvantages. 268. Historical. 269. Aëration Tank. 270. Sedimentation Tank. 271. Reaëration Tank. 272. Air Distribution....

55. General. 56. Manholes. 57. Lampholes. 58. Street Inlets. 59. Catch-basins. 60. Grease Traps. 61. Flush-tanks. 62. Siphons. 63. Regulators. 64. Junctions. 65. Outlets. 66. Fo...