Sewer

“ It has been found by experiment that in a flat bottomed sewer, four feet wide, having a fall of eight inches in one hundred feet, a stream of water one inch depth, runs very sluggishly, while the same water running through a 12-inch pipe, laid on the same inclination, forms a rapid stream, carrying away the heavy silt which was deposited in the broad sewer. ”

“ In the construction of the sewers, man-holes, built to the surface, are placed at sufficient intervals, and at all points where the course of the sewer changes, so that a light placed at one of these may be seen from the next one;—the contractor being required to lay the sewer so that the light may be thus seen, a straight line both of inclination and direction is secured. ”

“ A sewer is a misunderstanding; and when drainage, with its double functions, restoring what it takes, is everywhere substituted for the sewer, that simple and impoverishing washing, and is also combined with the data of a new social economy, the produce of the soil will be increased tenfold, and the problem of misery will be singularly attenuated. ”

“ Every sewer which we construct pollutes some stream, every stream flows into some river, and every river sends up a pestilential exhalation, which decimates our population, by zymotic diseases, and sows the seed of future maladies in thousands who are unconscious of its immediate effects. ”

“ The great sewer, which is tunnel-like in dimensions, being 16 feet high and 18 feet broad, is, on occasions of a visit, lighted with lamps alternately red and blue, and as these stretch away into the distance the effect is decidedly striking. ”

“ It has been the writer's practice to design sanitary sewer systems on the basis of the water consumption, and to assume the whole daily amount to reach the sewer in 16 hours, thus providing capacity sufficient to care for the maximum or wash-day flow without causing the sewers to run above the calculated hydraulic gradient, which should be placed within the pipe so as to provide air space for ventilation under all circumstances. ”

“ Where a wide surface is given to a small quantity of flowing sewage, it stagnates slowly along the bottom of the sewer, leaving frequent deposits to undergo decomposition and create foul air, if not to choke the sewer, a result often produced ”

“ The house sewer is shown leading to the settling tank, and from the siphon chamber adjoining the settling tank the main carrier or effluent sewer is shown leading to a diverting manhole from which the effluent is carried at each discharge of the siphon to the lateral lines of sub-surface tiling by the two branch carriers. ”

“ Sewers are often paid for, particularly for small sizes, per foot of completed sewer as measured along the center line of the pipe parallel to the surface of the ground with the exterior length of manholes and other structures deducted. ”

“ Where the outfall sewage enters the disposal works provide a pair of open catch-pits (or grit-chambers) , each twice as wide as, and 2 feet deeper than the sewer, with sluices allowing the sewage to pass through one pit at a time in its free course, while the other pit is being dried and the deposited detritus dug out. ”

“ They think that a sewer in the street, and a pipe leading to it from the house, is good drainage. All the while the sewer may be nothing but a laboratory from which epidemic disease and ill health is being distilled into the house. No house with any untrapped drain pipe communicating immediately with a sewer, whether it be from water-closet, sink, or gully-grate, can ever be healthy. ”

“ If we should be taken off our legs there’s a heavy fall—about 3 feet—just before you comes to the mouth of the sewer, and if we was to get there, the water is so rapid nothing could save us. When we goes to work we nails our lanterns up to the crown of the sewer. When the slide is lifted up the rush is very great, and takes all before it. ”

“ If the cellar or basement contains plumbing fixtures, the house sewer should enter 1 to 2 feet below the cellar floor. If all plumbing fixtures are on the floors above, the sewer may enter at no greater depth than necessary to insure protection from frost outside the cellar wall. Digging the trench and laying the pipe should begin at the tank or lower end. The large end of the pipes, called the hub, should face uphill, and the barrel of each pipe should have even bearing throughout its length. ”

“ They each have their drainage into the sewer of the street, and this is trapped and trapped again, as in the houses of our old plutocratic cities, to keep the poison of the sewer from getting into the houses. ”

“ In English law a “sewer,” as distinguished from a “drain,” is that which carries away the sewage of more houses or other buildings than one. Many fanciful derivations of the word have been given, but there seems no doubt that the word is from O. Fr. ”

“ The main sewer or culvert runs directly through the middle of the city; it is built of large stone arched, with inlet at almost every square. It took twenty years to build it, and is considered by all scientific men to be one of the best works in the world. ”

“ In the case of either large or small sewers, it will be vastly increased if we compel every householder who makes a connection with the sewer, to carry a drain and soil pipe, nowhere less than four inches in diameter, from the point of junction with the main line to the open air above the roof. ”

“ Pumping and Drainage.—Ground water is to be expected in nearly all sewer construction and provision should be made for its care. Where geological conditions are well known or where previous excavations have been made and it is known that no ground water exists it may be safe to make no provision for encountering ground water. ”

“ Shadow of steel knife edge which forms the lip of the weir can be seen through the falling sewage.
The overflow weir and the leaping weir have no moving parts and are used for the regulation of the flow in sewers. A leaping weir is formed by a gap in the invert of a sewer through which the dry weather flow will fall and over which a portion or all of the storm flow will leap. One form of leaping weir is shown in Fig. 43. An overflow weir is formed by an opening in the side of a sewer high enough to permit the discharge of excess flow into a relief channel. ”

“ It has also become the frequent practice of designers to give every length of sewer all the grade possible, regardless of the fact, taught both by hydraulics and experience, that the best grade is that which will give as much depth of flow as is consistent with a scouring velocity. ”

“ Human excrements (feces and urine) as found in closets and privy vaults are known as night soil. These wastes may be flushed away with running water, and there may be added the discharges from washbasins, bathtubs, kitchen and slop sinks, laundry trays, washing vats, and floor drains. This refuse liquid product is sewage, and the underground pipe which conveys it is a sewer. Since sewers carry foul matter they should be water-tight, and this feature of their construction distinguishes them from drains removing relatively pure surface or ground water. ”

“ The natural curve which the sewage would follow in its downward path as it flowed out from the end of the sewer can then be drawn out for the various depths, taking into account the fact that the velocity at the invert and sides of the sewer is less than the average velocity of flow. ”

“ The maximum rate at which the rain-water will reach the outfall sewer will determine the size of the sewer and capacity of the pumping plant, if any, while if the sewage is to be stored during certain periods of the tide the capacity of the reservoir will depend upon the total quantity of rain-water entering it during such periods, irrespective of the rate of flow. ”

“ The great advantage of the sewer system, as contradistinguished from the cesspool system of defecation, is, that it admits of the wet refuse being removed from the neighbourhood of the house as soon as it is produced ”

“ When the sewer is ordered to be flushed—and there is no periodical or regular observance of time in the operation—the men enter the sewers and rake up the deposit, loosening it everywhere, so as to render the whole easy to be swept along by the power of the volume of water. The sewers generally are, in their widest part, provided with grooves, or, as the men style them, “framings.” ”

“ Every house or building must be separately and independently connected with the street-sewer.
6. Where the ground is made or filled in, the house-sewer—that is to say, the portion of the drain extending from the public sewer to the front wall—must be of cast-iron, with the joints properly calked with lead. ”

“ In the matter of sewer construction, regarded now so necessary in all civilised cities and thickly-settled communities as one of the means of proper sanitation, great improvements have been made in deep sewerage, in which the work is largely performed below the surface and with little obstruction to street traffic. ”

“ The elevation of the surface at the upper and lower manholes is read from the profile.
The depth of the sewer below the ground surface is first determined. Sewers should be sufficiently deep to drain cellars of ordinary depth. In residential districts cellars are seldom more than 5 feet below the ground surface. To this depth must be added the drop necessary for the grade of the house sewer. Six-inch pipe laid on a minimum grade of 1.67 per cent is a common size and slope restriction for house drains or sewers. ”

“ All philanthropy—no age has seen more of it than our own—is only a savoury fumigation burning at the mouth of a sewer. This incense offering makes the air more endurable for passers-by, but it does not hinder the infection in the sewer from spreading. ”

“ Organization.—The number of men employed on a brick or block sewer is proportioned according to the size of the sewer and the working conditions. The number of men working on different tasks usually bears the same ratio to the number of masons employed, regardless of the size of the work. ”

“ The house sewer or drain should have a grade or fall of not less than 9 inches in 100 feet. Preferably, the sewer should be laid at the above minimum grade for at least 50 feet or so before it enters the tank in order to prevent excessive velocity in the sewage flow at this point. At the entrance to the tank the sewer should be provided with an elbow so that the sewage will be discharged downward below the surface. Similarly, if an outlet pipe from the tank is used, as shown in Fig. ”

“ The present houses are founded chiefly on the artificial or ‘made ground,’ while the sewers are made through the gravel; and it is known practically, that however charged with water the gravel of a district may be, the springs for a considerable distance round are drawn down by making a sewer, and the wells that had water within a few feet of the surface have again to be sunk below the bottom of the sewer to reach the water. ”

“ No person shall make or maintain any connection with any public sewer or appurtenance thereof whereby there may be conveyed into the same any hot, suffocating, corrosive, inflammable or explosive liquid, gas, vapor, substance or material of any kind ... ”

“ Not only, let it be borne in mind, is the sewage carried off beneath the ground, but even the very sewers themselves kept so clean and neat, and withal so perfectly ventilated, that ladies and gentlemen may pass through them without soiling their clothing or offence to the senses. ”

“ Above a point 2 feet above the top of the sewer the method pursued and the care observed in backfilling will depend on the character of the backfilling material and the location of the sewer. If the sewer is in a paved street the backfill is spread in layers 6 inches thick and tamped with rammers weighing about 40 pounds with a surface of about 30 square inches. One man tamping for each man shoveling is frequently specified. ”

“ It is loose, as is the trough, and both can be lifted out when it is desired to have access to the invert of the sewer. The screen is self- cleansing, as any floating matter which may be washed against it does not stop on it and reduce its discharging capacity, but is gradually drawn down by the flow of the sewage towards the diverting plate under which it will be carried. The heavier matter in the sewage which flows along the invert will pass under the plate and be carried through to the outfall works, instead of escaping by the overflow, and perhaps creating a nuisance at that point. ”

“ In soft material which would give poor support to a sewer with a rounded exterior, the bottom of the trench is cut horizontal and a concrete cradle of poorer quality than that in the finished sewer is poured on the soft ground, on a board platform, on piles, or on cribbing supported on piles. ”

“ In the larger sewers the distances are sometimes made greater but inadvisedly so, since quick means of escape should be provided for workmen from a sudden rise of water in the sewer, or the effect of an asphyxiating gas. In the preliminary layout the manholes are located at pipe intersections, changes in direction, and not over 300 to 500 feet apart on long straight runs at convenient points such as opposite street intersections where other sewers may enter. ”

“ The ball is caught at the next manhole below. A net should be placed for catching the ball and a small dam to prevent the dislodged detritus from passing down into the next length of pipe. The feeding of the balls into the sewer is continued, using larger and larger sizes, until the sewer is clean. This method is particularly useful for the removal of sludge deposits, but it is not effective against roots and grease. 339The balls should be sufficiently light to float. Hollow metal balls are better than heavier wooden ones.
Fig. 143.—Cable and Windlass Method of Cleaning Sewers. ”