CHAPTER XV Tue COLLECTION AND DisposAL OF REFUSE, THE (Part 1)

CHAPTER XV Tue COLLECTION AND DisposAL OF REFUSE, THE CLEANSING OF STREETS, DISINFECTION AND SMOKE ABATEMENT The disposal of refuse is a most difficult but important part of the work of local authorities. The nature and quantity of the refuse varies with the locality to some extent, particularly that part of it which comes from trade and industry. Average Composition of House Refuse. An average of com- position of house refuse, expressed as percentages of weight, would be about as follows: Fine dust 28 per cent., cinders 26 per cent., paper 15 per cent., putrescible matter 14 per cent., cans and other metal 4 per cent., glass and crockery 3 per cent., rags 2 per cent., bone 1 per cent., unclassified matter 7 per cent. Average Calorific Value of House Refuse. The calorific or heat- ing value is usually between one-fourth and one-seventh that of good steam coal. It should be borne in mind, however, that the composition and calorific value vary considerably according to the season, mainly because coal fires are more general in winter than in summer. It is interesting also to note that, owing to the greater use of gas stoves, electric cookers, and such appliances, the refuse is altering in character, containing much less cinders and ashes than hitherto, causing the calorific or fuel value to be lower. A natural corollary of this is that the cost of destruction is increasing far more steeply than increase in wages would justify. In some places refuse destructors, which used to be worked entirely by refuse, have now to be assisted by means of small coal, coke breeze or cheap oil. When it is pointed out that the average amount of refuse col- lected per annum is about a quarter of a ton per head of population, it will be seen that the dealing with the waste matters of a large population is a big undertaking. The most sanitary method of dealing with it is to cremate it. This is done, in a well-administered locality, in special furnaces, known as refuse destructors. Much could be done to reduce the difficulty and cost of destroying it if householders realised that they DISPOSAL OF REFUSE, ETC, 459 had some personal liability in the matter, and burned as much re- fuse as possible in their stoves or grates, preferably depositing waste vegetable matter in compost heaps in their gardens. Storage of Refuse by Householder. Fixed ashpits are fortunately a thing of the past and for dwelling-houses portable galvanised iron bins, of a capacity not exceeding 2 cubic feet, should be in- sisted on. The gauge of the iron is often No. 20 B.W.G. and they are sometimes, but not usually, corrugated to give increased strength. A seating hoop should be provided at the base, to keep the floor of the bin off the ground, and the top edge should be strengthened by a stout galvanised iron hoop, to help preserve the shape; two strong galvanised iron handles are riveted to the body. It should be covered by a lid with a deep rim, which should fit loosely over the body, as bins often get rough usage by the dust- men and some distortion in shape may occur. The bin should be kept on an impervious floor, such as in a paved yard. It should be strongly impressed on householders that they should not put liquids or very wet refuse in bins and that they should not burn refuse in them. Collection of Refuse. The usual practice in large towns is for refuse to be collected from dwelling-houses once in each week, with a more frequent call (perhaps daily) at hotels, restaurants and large blocks of flats. A weekly collection is by no means an ideal arrangement, for it is not desirable that putrescible matter should be kept so long in the immediate neighbourhood of dwellings and some towns have instituted a bi-weekly, or even daily, call with conspicuous success and at no great increase in cost. If bins are provided for flats and tenements they should be much smaller than those used for dwelling-houses and they should be emptied each day to a large “property container”, placed out- side the building at ground level, serving the block. This daily removal from the flat is necessary because the bins will usually be kept indoors; for the same reason they should be made pleasing in appearance, enamelled inside and out, with a hinged lid which in some types is made to open by pressing a lever with the foot. Dust Chutes for Flatted Dwellings. An alternative method of removing refuse from flats is by its discharge to the ground floor through chutes 12 or 14 inches in diameter, with a well-fitting door at each flat. The doors should not be placed inside the flats if it can be avoided, as some nuisance from smell and dust is unavoid- _ able. The chute should extend upwards above the roof, like a chimney, for ventilation purposes, and there should be facilities _ for washing it down with water periodically. 460 DISPOSAL OF REFUSE, ETC. SINK WITH REMOVABLE PLATE AND PLUG 4” WASTE'AND RUBBISH PIPE > _ —o a . ar aN UBB/. KITCHEN || CONTAINER dl te RUBBISH ——— PLUG AND CRUSHER JOINTS DETA/L OF GARCHEY SINK AND REFUSE RECE/VER. REFUSE WHICH WILL NOT PASS THE GAUGE MUST BE REMOVED ANDO CUT SMALLER OR OTHERW/SE DISPOSED OF. SUCTION PIPE FROM DISPOSAL STATION / LS a OUTLET 70 ORIER AND AL DESTRUCTOR FURNACE ei TRAPPED OUTLET .: | ) FOR WASTE AND FLUSHING WATER COLLECTING PIT CONTROL '‘C’ IN COLLECTION PIT MUST BE CLOSED WHEN BULK OF RUBBISH HAS BEEN REMOVED BY SUCTION P/PE ANO BEFORE THE MAIN BODY OF WATER 1S DRAWN INTO THE OUTLET P/PE. 446. THE GARCHEY METHOD OF REFUSE REMOV- Al FOR LARGE BLOCKS OF FLATS. DISPOSAL OF REFUSE, ETC. 461 The property container for a block of flats will be a solidly- built steel box, capable of holding 2 or 2} cubic yards of refuse, fitted with dust-proof sliding lids, with four small wheels running on rails on an iron stand, from which it can be removed to the collecting vehicles and taken away, a cleansed container being substituted on the stand. The Garchey System of Refuse Storage. This is a system of water carriage for refuse in large blocks of flats and tenements to replace ordinary dust chutes which are apt to cause nuisance from dust and smell especially in hot summer weather. It was first used in Paris, but has been used with success at Leeds and else- where in this country. The method (which is illustrated in Fig. 446) involves the pro- vision of a special type of kitchen sink with a 6-inch diameter outlet in its bottom, normally closed by a metal cap in the centre of which is the ordinary waste outlet. The sink is used for ordinary purposes with the cap fixed in place, whilst solid refuse can be disposed of through the large outlet when the cap is removed. Under the sink is a cast-iron pear-shaped receiver whose outlet is closed by a plunger, fitted with an overflow, and into this both liquid wastes and solid refuse pass. Below the receiver is a trap, with 2-inch water seal and anti-siphonage pipe, connecting it to a vertical cast-iron gravitation pipe, extending from below ground to a level above the roof, being open at the top like a soil-pipe for ventilation purposes. The contents of the receiver are from time to time discharged to this by pulling up the plunger which normally closes the outlet of the receiver. The gravitation pipe leads to an air-tight collecting chamber, placed underground outside the building. This has a trapped overflow, leading to the main drain or sewer, for continuous dis- charge of liquids, but the solids at the bottom are removed inter- mittently. This is done through a suction pipe which leads to the receiving tank of a disposal station, discharge being controlled by a hand-operated valve. The suction is effected by a motor- driven vacuum pump placed at the disposal station and it is claimed that discharge can be obtained for a distance of 5 miles by this means although, for obvious reasons, the receiving and destructor station is usually provided by the landlord of the com- plete block or series of blocks of flats and in the grounds or cur- tilage of the flats. When the solids and liquids reach the receiving tank they are lifted together by compressed air to a feed tank from which they gravitate to a hydro-extractor, where water is removed by centrifugal action; the residual refuse falls into an incinerator, 462 DISPOSAL OF REFUSE, ETC. the heat from which can be used for a laundry or similar purposes. It should be added that it is made impossible for the tenant to pass into the receiver from the sink articles so large that they might cause an obstruction. Large articles, if they cannot be broken up, must be disposed of in some other way. The advantages of the Garchey method, as compared with the discharge to a container by chutes, are that dust and smell are avoided. The capital outlay is greater than that of dust chutes but the running costs are not very much greater. Vehicles Used for Dust Collection. At the beginning of this century, the vehicles used for dust collection were horse-drawn wooden carts with open tops and high sides and the dustmen had to mount a short ladder with the bin, before tipping, in a cloud of dust, into the cart. To-day, they are usually motor-driven and controlled. It is important that the vans should be enclosed and that it should be possible to discharge the contents of bins without the dust being blown about. There are many good designs of van, covered by close-fitting steel shutters; in some of these the shutters at the sides are raised and lowered by pedals, operated by the dustmen before and after emptying the contents of a bin. They have small wheels and a long low body to avoid the use of ladders. A more recent develop- ment is the moving floor type of vehicle. This type has a floor which resembles a rolling shutter shopblind in appearance, carrying a barrier about 3 feet high extending across the whole width of the vehicle. Loading is effected at the rear end of the van, behind the barrier; when the refuse reaches the level of the top of the barrier the floor and barrier are moved forward a little and loading is con- tinued, the floor being moved forward at intervals until the barrier reaches the driver’s end. Most modern collecting vehicles have devices by which the body can be tipped to a steep angle for discharging its contents quickly and completely at the place of disposal, the tipping mechanism being actuated by gearing from the engine which normally propels the vehicle. Another excellent modern vehicle has inside it a helical screw which gathers the refuse, as it is shot into the body, passes it for- ward and compresses it. Tipping gear is not needed, as the load is emptied by reversal of rotation of the serew. An advantage of this type is that a much greater weight can be carried in equal space, due to the compression. Refuse Containers for Hotels, Flats, etc., in Populous Areas. DISPOSAL OF REFUSE, ETC, 468 Property containers from hotels and blocks of flats can be carried conveniently by a motor lorry, of which the body can be tilted to form a sloping platform. The containers run on their own wheels and are drawn up the platform by a cable worked from the engine, after which the platform is brought to the horizontal. Method of Locomotion. It is not possible to generalise as to the best method of propelling collecting vehicles. Whilst to-day the petrol engine is most commonly used, it is not at its best when used in a service which requires frequent stopping and waiting; on the other hand it is most efficient when long distances have to be travelled to the place of disposal. Where the houses are rather scattered and there is no great length of haul to the tip, horse- drawn vehicles may still be the best proposition and there are to- day horse-drawn vehicles of quite satisfactory design; but where development is more dense, or longer hauls to tip are necessary, the petrol-driven vehicle would be preferred. Some districts find it an economy to use a fleet of tractors with a larger number of trailers which can be moved quickly to strategic points for filling and then transported (two or three at a time) to the place of disposal. Electrically-driven vehicles are occasionally used and they have some distinct advantages, for there is little or no loss at stopping and starting and no power is used when the van is stationary. The main objections to them are that the accumulators, which are used to drive them, are a considerable dead weight, that mainten- ance of accumulators is a serious item and that the speed of such vehicles in the travel to the tip is invariably low. In some cases special means have been devised for taking ad- vantage of the merits of the horse in a collecting vehicle and of the petrol engine in the travel to tip. One such method is to collect the refuse into small horse-drawn containers, holding about 38 tons, and to haul these, when full, up an inclinable ramp on to a motor lorry for haulage to tip, the horse being transferred to an empty container delivered by the lorry. Another method is to collect the refuse in trailers, which can be horse-drawn in the col- lection and coupled to a tractor in the haul. . Methods of Disposal. While the best method of disposal is by burning, many other methods are in use. In the case of some towns near the sea, refuse is barged out to sea in special barges and dropped into deep water. This method has its drawbacks; in winter the weather is often such that the barges dare not go out for sometimes a week at a time, which necessitates storage and consequent nuisance. Again, the tide will often bring a quantity of the lighter particles of refuse back. 464 DISPOSAL OF REFUSE, ETC. “Controlled Tipping”. In many districts refuse is tipped on low-lying lands, sand wastes, moorlands, disused quarries, etc. There has in recent times been much criticism of this practice, on the grounds that such tips are unsightly, form breeding-places for rats and flies, and cause unpleasant smells, sometimes increased by combustion of the refuse. To prevent these results the follow- ing precautions must be taken: Before tipping is begun the surface soil of the site should be removed and set aside for covering the refuse; the refuse should be spread evenly to a depth not exceeding 6 feet and neatly banked; tins should be raked to the foot of the bank, placed upright and filled with earth; carpets, linos, rags, etc., laid flat at the foot of the bank and covered; glass and china should be broken up and paper consolidated by ramming; cinders and ashes should be brought to the top; each day’s tippings should be covered with a layer of earth at least 9 inches thick. Whilst “‘controlled” tipping of this character is not as satis- factory, from the health point of view, as burning, it will generally be much less costly. The refuse will be quite harmless in two or three years and the site will be suitable for agricultural purposes or for use as a public open space. Salvage. When refuse is to be burnt it is sometimes found that it is profitable first to salvage from it such articles as cinders, rags, tins and bottles; the practice, too, has the advantage of diminishing the amount which has to be incinerated. The sal- vaging is done partly by screening, partly by hand-picking, and partly by the use of electro-magnets to pick out iron, Cinders may be saleable for brick-making, rags for paper- making; tin and solder can be recovered from cans by chemical or electrolytic methods, and the remaining iron in the cans will be saleable if compressed into bales. The prices obtained in pre- war years for these by-products, however, seldom repaid the cost of their separation. During the late war special efforts were made to salvage metals, paper, rags and other useful materials; householders were asked, in the national interest, to keep these clean and separate from other refuse and (in many districts) to take them to depots or dumps, from which the salvaged materials were collected by the local authority. Refuse can sometimes be sold, or given away, to farmers as manure, and it much improves heavy clay soils. Disposal in this way will, however, be impossible unless the larger articles have been removed by salvaging, or pulverised. DISPOSAL OF REFUSE, ETC. 465 Pulverising. Pulverising is done by heavy hammers, swinging in a revolving drum, the material falling as dust through a screen. Tins, and other articles which cannot be broken, must first be removed. The object of pulverisation is to make the refuse more suitable as manure. Refuse Destructors. In the early days of destructors objection was made that they were nuisances to a neighbourhood, producing offensive smells, and that fine ash or dust was carried up the chim- ney shaft and scattered for a considerable distance around. Before the scientific principles underlying their construction were under- stood, there is little doubt that such complaints were well founded, but such great advances have been made that sanitarians are now agreed that the plan of disposing of towns’ refuse by burning is the only really satisfactory one. Essentials of a Satisfactory Refuse Destructor. The essentials of a satisfactory destructor installation are that its position should be fairly central, to economise cost of cartage;