Sewage

“ I am delighted to hear that you are publishing a book about sewage treatment.
The sewage farms at Aldershot and the Royal Military College afford ample proof of what a sensible practical man can do. But it is not every one who knows what those farms were before you took charge of them, nor do I think that any one seeing them now could conceive their previous condition. It is to that I can testify; you have turned putrid sewage bogs into fertile fields. ”

“ The principles to be kept in the foreground are the disposal of sewage in the superficial layers of the soil in not too great quantity, the disinfection of the stools of the sick with lime before such disposition is made, the digging of wells in places kept permanently in grass and at some distance from barnyards, and, above all, their thorough protection from contamination from the surface and from the soil immediately below the surface. ”

“ 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. ”

“ In order to plant vegetables on such a hill, small furrows may be made along the hill and laid out with great care so that the flow of sewage in the furrows shall be only at a slow velocity, so slow that the soil can absorb the moisture as the water passes along. By zigzagging this furrow back and forth down the hillside, vegetation on the hill will receive the benefit of the water, and if any of the sewage succeeds in reaching the bottom of the hill, it will be so purified that it may be safely discharged into any depression or watercourse there found. ”

“ Sewerage is the name of the system of conduits and appurtenances designed to carry off the sewage. It is also used to indicate anything pertaining to sewers.
A difference is made between sanitary sewage, storm sewage, and industrial wastes. Sanitary sewage, sometimes called domestic sewage, is the liquid wastes discharged from residences or institutions, and contains water closet, laundry and kitchen wastes. Storm sewage is the surface run-off which reaches the sewers during and immediately after a storm. Industrial wastes are the liquid waste products discharged from industrial plants. ”

“ Some of the substances contained in raw sewage remain in the bed, no matter how carefully the sewage has been previously strained, and these, in combination with the slimy surface coating of the component particles, the accumulation of mineralised substances in the pores, the consolidation of the bed, the disintegration of the filling material, and the liquid retained, lead gradually but surely to the silting or sludging up of the bed. ”

“ DISPOSAL OF SEWAGE.
The vital thing which thus presents itself is the disposal of fecal matter and other refuse so that the wells, upon which most rural families depend for their drinking water, may remain pure. To this matter we will first turn our attention.
Every person who tills the soil is acquainted with the remarkable transforming power of the superficial layers of the earth upon manure and excrement. Out of these offensive wastes harmless substances are produced which are essential to the growth of vegetation. ”

“ 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. ”

“ For a single house or small village, the sewage may be stored in a tank, with an overflow-pipe, out of which the liquid parts escape, and are systematically used to irrigate land, while the solid parts are removed at intervals. ”

“ 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. ”

“ In order to properly understand a reasonable method of treatment some consideration must be given to the composition of sewage. This is chiefly water with which is mixed a small amount of animal, vegetable, and mineral matter. Roughly speaking, the amount of mineral dirt is about one tablespoonful to a barrelful of water, and the combined amount of animal and vegetable matter amounts to another tablespoonful. ”

“ No attempt is made to purify sewage completely, or on a practical scale to make drinking water.
5. Methods of Treatment.—Screening and sedimentation are the primary methods for the treatment of sewage. By these methods a portion of the floating and settleable solids are removed, preventing the formation of unsightly scum and putrefying sludge banks. Chemicals are sometimes added to the sewage to form a heavy flocculent precipitate which hastens sedimentation of the solid matters in the sewage. ”

“ A separate system of sewers is one in which only sanitary sewage or industrial wastes or both are allowed to flow. Storm sewers carry only surface drainage, exclusive of sanitary sewage. Combined sewers carry both sanitary and storm sewage. ”

“ Sewage or impure drainage water should never be discharged into or upon ground draining toward a well, spring, or other source of water supply. Neither should such wastes be discharged into 'Openings in rock, an abandoned well, nor a hole, cesspool, vault, or tank so located that pollution can escape into water-bearing earth or rock. Whatever the system of sewage disposal, it should be entirely and widely separated from the water supply. ”

“ I may here mention that the system of sewage is far superior to any yet devised on Earth. No particle of waste is allowed to pollute the waters. The whole is deodorised by an exceedingly simple process, and, whether in town or country, carried away daily and applied to its natural use in fertilising the soil. ”

“ A tight, underground septic tank with shallow distribution of the effluent in porous soil generally is the safest and least troublesome method of treating sewage upon the farm, while at the same time more or less of the irrigating and manurial value of the sewage may be realized. ”

“ Where the contour of the ground does not admit of a sufficient gradient from the gathering ground to the place of destination, the sewage must be pumped to a higher level at one or more points in its course. To minimize this necessity, and also or other reasons, it is frequently desirable not to gather sewage from the whole area into a single main, but to collect the sewage of higher portions of the town by a separate high level or interception sewer. ”

“ The material to be handled is entirely domestic sewage and varies only according to the amount of water used in the house, making the sewage of greater or less strength according as less or more water is used. Sewage from a single house differs only in one respect disadvantageously from city sewage, namely, in the fact that the sewage, not having to pass through a long length of pipe, comes to the place of disposal in what is known as a fresh condition ”

“ The average quantity of sewage pumped to the farms and distributed amounts to from 6,000,000 to 7,000,000 gallons per acre per year, or in other words each acre serves for 750 people. The area farmed is divided into small beds about 150 by 200 feet separated from each other by slight embankments and ditches for distributing the sewage over the surface. ”

“ By suitable adjustment of these penstocks, partially closing those through which the sewage has a tendency to flow most freely and opening the others, there should be no difficulty in securing a uniform distribution of the sewage. ”

“ The essence of the system is the use of horizontal plates to receive and retain the deposit of solid matters in suspension in the sewage, so that they are decomposed or digested, after the settled liquid has been drawn off, by aerobic bacteria and other higher forms of life, including worms, all of which thrive only in the presence of air. The beds are filled with the raw sewage, which is then allowed to remain for a period of about two hours for quiescent settlement, after which the liquid is slowly drawn off. ”

“ But if the ground is flat, it will be remembered that before many weeks the sewage ceases to sink into it; the ground becomes "sewage-sick," as they say in England, and a thick, dark-colored pool of sewage gradually forms, which smells abominably. ”

“ Sew′erage, a system of underground pipes or conduits for the removal of sewage or the rain-water of a place. Sewerage is required for sanitary reasons in towns and cities. In the country, where population is not dense, sewage can be disposed of without any elaborate system, though care must always be taken that the water-supply is not contaminated. The construction of elaborate sewer-systems is found in ancient cities, as Babylon, Jerusalem and Rome, but it is only within recent years that it has received the attention it deserves in modern cities. ”

“ The main purpose of home sewerage works is to get rid of sewage in such way as (1) to guard against the transmission of disease germs through drinking water, flies, or other means; (2) to avoid creating nuisance. What is the best method and what the best outfit are questions not to be answered offhand from afar. A treatment that is a success in one location may be a failure in another. In every instance decision should be based upon field data and full knowledge of the local needs and conditions. An installation planned from assumed conditions may work harm. ”

“ Physical and chemical precipitation. (4) Intermittent filtration. (5) Land irrigation. (6) "Bacterial" methods.
Discharge into Waters.—The easiest way to dispose of sewage is to let it flow into the sea or other running water course. The objections to sewage discharging into the rivers and lakes near cities, and especially such lakes and rivers as supply water to the municipalities, are obvious. But as water can purify a great amount of sewage, this method is still in vogue in certain places, although it is to be hoped that it will in the near future be superseded by more proper methods. ”

“ In 99those parts of the country where the water itself has a value, as in the irrigated lands of the West, the fertilizing elements of the sewage would be added to the value of the water, so that sewage used for irrigation would be worth not merely the value of the water alone, but also the value of the fertilizer present in that water. ”

“ The control of sewage treatment plant effluents so as to avoid the poisoning of fish life or the contamination of shell fish is likewise important. The study of plankton and macroscopic life in the treatment of sewage is an open field for research.
216. Variations in the Quality of Sewage.—The quality of sewage varies with the hour of the day and the season of the year. Some of the causes of these variations are: changes in the amount of diluting water due to the inflow of storm water or flushing of the streets or sewers ”

“ Activated Sludge Process Sewage treatment by aeration in the presence of sludge is the latest development in sewage disposal, and the process is attracting a great deal of attention in America. Milwaukee has constructed a plant to treat two million gallons of sewage a day. ”

“ When a city is located on the seashore or near a large lake or stream the screening out of the heavy particles before the sewage is discharged together with dilution will prevent active decomposition and putrefaction of the sewage the body of water receives and the esthetic senses of the community will not be offended. ”

“ Concerning land treatment, the Commissioners observe, “We doubt if any land is entirely useless,” but further on they observe that peat and stiff clay lands are generally unsuitable for the purification of sewage. ”

“ Fig. 55.—Sludge Press.
The sewage enters the works by the channel A, and passes first through the bar screen B. The screening is necessary to remove anything that would tend to produce obstruction in the inlets to the press chambers and be liable to cause breakage of the press plates. The sewage next meets with the milk of lime from the lime mixer C, with which it is mixed by flowing along the gravitation mixer D. The pneumatic lime mixer produces lime milk of a constant strength, and the flow is adjusted in proportion to the requirements of the sewage. ”

“ Passing now to the aerobic stage of sewage purification we find it universally admitted, that a good loam resting on very porous sand or gravel, affords the best medium for work by the oxygen-loving nitrifying organisms [Pg 6] when they are supplied with constantly moving liquid sewage, and given intermittent periods for the aeration of the pores of the soil. ”

“ How extremely simple it all is!” was the remark of a recent visitor at a sewage farm—which encourages me to venture on publication of the most recent discussions on a “problem” complicated by engineers, chemists, bacteriologists and inventors of systems, who have raised clouds of dust through which it is difficult for ratepayers and district councillors to find their way to “the best practical and available means of sewage disposal.” ”

“ In large installations for cities and villages it is usual to install either plural alternating siphons or apparatus known as sewage feeds, by means of which the contents of the dosing chamber are discharged upon the different beds in rotation, there generally being four or five beds constructed in each unit. ”