CHAPTER VII. ESTIMATES OF COST

Cost of material: of laying sewers and drains; of sand; of 112–128 excavating and refilling; of rock excavation; of concrete work; of valves; of dosing devices; of filling material for beds; of finishing and cleaning up. Table to show items to be considered in estimate of cost.

LIST OF FIGURES

A sub-surface irrigation sewage-disposal plant _Frontispiece_

FIGURE PAGE

1. Plan of settling tank 15

2. Longitudinal section of settling tank 17

3. Sketch of settling tank with longitudinal 19 partition wall

4. Forms used for building side walls for concrete 23 tank

5. View of settling tank, showing baffles, sludge 26 pipe, drain pipe, and inlet and outlet pipes

6. Section showing tank with concrete roof and form 28 for constructing roof

7. Form for manhole opening 30

8. Plan and longitudinal section of modified Imhoff 33 tank

9. Vertical cross-section of modified Imhoff tank 34

10. Sludge valve for floor of tank 38

11. Sludge valve for side wall of tank 39

12. Sluice gate valve made by Coffin Valve Co 40

13. Ordinary gate valve 40

14. English slide valve with wedge-lock handle 41

15. Flap valve attached to length of sewer pipe 42

16. Flap valve with metallic seat attached 43

17. Flap valve with loose-link hinges 44

18. Intermittent dosing apparatus made by Ansonia 45 Manufacturing Co.

19. Simplest form of automatic siphon 46

20. Van Vranken automatic siphon 47

21. Miller automatic siphon 48

22. Double alternating siphons of the “Merritt” type 49

23. Triple alternating siphons of the Miller type 50

24. Single “Merritt” automatic siphon 51

25. Air-lock siphon for admitting and releasing 52 sewage from each one of four beds in regular order

26. Plan and section of sub-surface irrigation system 61

27. Plan and section of a portion of a sub-surface 62 irrigation system

28. Y-branch of vitrified tile pipe 64

29. Eighth bend of vitrified tile pipe 64

30. Sub-surface tiling 65

31. Photograph of tile laid as if for sewage disposal 66

32. Sub-surface tiling with broken stone or gravel 67 surrounding pipe

33. Sub-surface systems on irregular ground 68

34. Special casting of double Y-branch with swinging 69 gate

35. Double Y-branch with valves on branches of main 70 carrier

36. Sub-surface tiling system with underdrains 71

37. View of sand-filter beds for village in 75 Massachusetts

38. Layout for intermittent sand filtration 78

39. Intermittent sand-filtration beds 79

40. Portion of distributing troughs for sand filters 80

41. General view of disposal plant at Bedford 81 Reformatory

42. View of sand filter with distribution trough. 82 Settling tank is at the end of the bed

43. View of diverting manhole 83

44. Plan of diverting manhole 84

45. Five-way diverting manhole 85

46. General plans of contact-bed system near Albany, 89 N. Y., opposite page

47. View of sprinkling filter at Dansville, Pa., in 95 winter

48. Distribution of sewage and arrangement of check 106 levees on a hillside

49. Distribution of sewage on a hillside of moderate 107 slope

50. Square beds for orchards according to some 108 Western practice

51. Grain-field in spring in process of irrigation 109

PRACTICAL METHODS OF

SEWAGE DISPOSAL

FOR

RESIDENCES, HOTELS AND INSTITUTIONS