Cleaning of Populated Areas

CLEANING OF POPULATED AREAS, a system of measures aimed at collecting and removing by means of removal the refuse that accumulates in populated areas. The removal of sewage by means of sewerage (see) constitutes a separate branch of sanitary engineering and should be considered separately. C.P.A. has primary importance for maintaining the sanitary improvement of cities and towns. The amount of refuse that accumulates in cities and other large centers is extremely large. In the absence of proper cleaning, most of it remains in the soil, polluting it and the groundwater which the population uses. The situation is especially grave in cities that have water supply but lack sewerage, where in addition to solid refuse, garbage, and street sweepings, a huge mass of wastewater must be removed, which is very expensive, as a result of which it is usually impossible to achieve complete removal and neutralization of refuse in non-sewered cities. According to Khlopin, only 10% of liquid refuse is practically accessible for removal, while according to data from the city of Moscow, only 6% is removed from non-sewered properties. In addition to polluting soil and water, poor C.P.A. leads to pollution of the air by gaseous products of decomposition of refuse and by dust from dirty streets. The inadequacy of cleaning is one of the factors in the development of epidemic diseases in populated areas, since refuse is a medium in which pathogenic microbes (typhoid fever, cholera, dysentery, tuberculosis, anthrax, etc.) can remain viable for a long time, and a place for breeding flies. There are observations that rational C.P.A. of refuse leads to a decrease in the incidence of helminthiasis among the population. The sanitary significance of cleaning is confirmed by examples from both Russian and foreign cities, where mortality, morbidity, and epidemic incidence decreased after the implementation of a number of sanitary-engineering measures (sewerage, paving, incineration). Despite the important sanitary significance of C.P.A., in most of our cities it is organized in a very primitive manner, and even large centers in the USSR still lag far behind the cities of Western Europe and America in terms of their improvement. Only in recent years, along with other areas of municipal construction, a number of improvements in the organization of city cleaning in the USSR has begun to be noted. In 1931, the state of affairs is characterized by the following data. In the USSR, 42 cities have sewerage, and in most of these cities it covers only a smaller part of the population. Even such large centers as Moscow and Leningrad are not fully sewered: in Moscow in 1931, there were about 900,000 residents living in houses without sewerage. Leningrad began building sewerage only after the revolution (beginning of operation in 1930). Only in 7 cities of the USSR does there exist a system for removal of solid refuse by municipal services (municipal cleaning), but almost everywhere it is implemented partially, not covering the entire city as a whole, namely: Moscow serves 400,000 people (15%), Leningrad - 300,000 people (18%), Kharkov - 150,000 people (33%), Odessa - 220,000 people (30%), Kiev - 80,000 people (13%), and only Yalta serves 75% of its residents, while Baku serves the entire city completely. Street cleaning remains almost everywhere very unsatisfactory, since in most cases it is carried out by janitors, being the responsibility of individual property owners. The situation is no better with the provision of cities with facilities for neutralizing refuse. Incineration stations exist only in Moscow, Leningrad, Odessa, Baku, and Kiev (closed since 1931), while in other cities there are only primitive dumps. According to data from a survey of 304 cities conducted by the People's Commissariat of Health of the RSFSR in 1926-27, sewage farms exist only in isolated cases (Vologda, Kostroma, Leningrad, Taganrog, Vladimir, Kovrov); 76 cities have more or less proper dump management, while the rest remove their sewage to completely unsuitable places. Moreover, in 79.5% of cities, dumps are located at a distance of no more than 2 km from residential buildings. The situation is no less acute in the cities of the Ukrainian SSR. In 1927, there were only 4 sewered cities in Ukraine, while the number of improved cesspools does not exceed 40% in large cities and 10% in small ones; pneumatic barrels are absent, the transport capacity is insufficient, dumps are not regulated, etc. The June plenum of the Central Committee of the All-Union Communist Party (Bolsheviks) (1931) sharply emphasized the lag of municipal services in Soviet cities behind the overall development of the country, the growth of industry, and the cultural demands of the population. In addition to this reason, common to various branches of urban improvement, in regard to C.P.A., there was also a special reason, consisting in the lack of clear understanding by workers in municipal services of the significance of removal and neutralization of refuse from the point of view of improving the material and living conditions of the urban population, and the underestimation of the importance of cleanliness in the struggle for culture. The resolutions of the aforementioned plenum of the Central Committee CPSU(b) not only state this gap and require a revision of the previous attitude to urban improvement, but also give a concrete program of action for establishing in each of the branches of urban economy in cities, linking the struggle for this program with the general tasks of the socialist reconstruction of cities. In regard to C.P.A., in the said resolution "On the Moscow municipal economy and on the development of the municipal economy of the USSR" given

Figure 1.

a completely clear directive: "to deploy during 1932 the production of municipal [watering, garbage (Fig. 1), etc.] automobiles, by constructing corresponding workshops at new automobile plants," in particular in Moscow as a city whose municipal economy must be a model for other cities; the entire business of cleaning must be mechanized within 2-3 years. This decision puts an end to the underestimation of the significance of the cleaning of populated areas and should serve as an impetus for large and fruitful work locally to bring our cities into a sanitary state. This work must be carried out by the forces of municipal economies and sanitary supervision on the basis of utilizing in our conditions the latest achievements of Western European and American technology and practice, and the maximum degree of initiative on the part of the public and our specialists. Sanitary technology has made very great strides in recent years in the timely removal and neutralization of refuse. Abroad, standard metal receptacles for refuse have been introduced into the practice of the majority of cities, and automobiles and electric vehicles are widely used for the removal of both solid and liquid refuse; many cities (England, Germany, France, and the USA) neutralize urban refuse by means of garbage incineration at large, technically well-equipped stations or in domestic garbage incineration furnaces. Concurrently with this, the task of utilizing urban refuse is also resolved either by collecting recyclable materials separately from other household refuse or at central sorting stations. Street cleaning is performed mechanically using sweeping, washing, and watering machines. These technical achievements became possible only after municipalities began to regard the cleaning of the city from garbage, snow, and filth as their immediate task. Of the large cities, only Paris retains the system of leasing cleaning services to a concessionaire in the form of a joint-stock company, which is obligated to remove daily all domestic garbage and street sweepings to 4 garbage incineration and utilization stations. Of the cities that have managed to set up cleaning at a very high level, Cologne can be named, where garbage is removed according to the exchange-container system (see Garbage) to a garbage incineration station located outside the city, and the receptacles are subjected to washing and disinfection at specially equipped washing and transfer stations. Street cleaning is carried out very thoroughly in Vienna, where it is performed by special trains consisting of several washing and sweeping machines. Thanks to the correct organization of the business and good operation, the productivity of washing and sweeping machines reaches very high figures (up to 120,000 m² for 8 hours of work). One of the reasons for the backwardness of our cities in the matter of cleaning must be recognized as the lack among the majority of municipal and sanitary workers of a clear understanding of the problem of cleaning of populated areas as a single system of measures aimed at protecting the soil from pollution. Usually, cleaning is in a fragmented state in the hands of various organizations that do not bear responsibility for the entire business of maintaining cleanliness in the city as a whole (municipal economies, municipal trusts, departments, household ownerships, private individuals). Corresponding to this same lack of a clear understanding of cleaning as a whole is the weak elaboration of cleaning issues in the general system of sanitary-technical knowledge. Until recently in the USSR, there were also no higher educational institutions that would train specialists of the appropriate qualification in city cleaning (engineers, technicians, sanitary doctors). Only now can it be presumed that this gap will be filled in view of the establishment of appropriate courses in higher educational institutions (institutes of municipal construction in Leningrad, Moscow, Kazan, and Novocherkassk, sanitary-prophylactic faculties of medical institutes). Of great importance for the development of this business is also the creation of the Academy of Municipal Economy, opening in accordance with the resolution of the same June plenum of the Central Committee of the All-Union Communist Party (Bolsheviks). The cleaning of populated areas must include all measures that have the purpose of removing and subsequently neutralizing refuse. In accordance with the modern understanding of the cleaning of populated areas, it should include the following parts: collection of refuse at the place of its generation, transport, and neutralization. Recently, a fourth moment has been joined to these three—utilization. By the type of refuse, cleaning can be divided into the following sections: 1) cleaning of properties from garbage, 2) cleaning of unsewered properties from feces and liquid slops, 3) cleaning of streets and squares, 4) removal and neutralization of economic and industrial refuse of animal origin (slaughterhouse waste, spoiled food products, animal carcasses), 5) removal and neutralization of other industrial refuse. In all stages of cleaning in relation to all types of refuse, the active participation of the sanitary doctor is necessary. Sanitary requirements boil down to the complete removal of all types of refuse, to the establishment of cleaning deadlines that must be minimal, to the hygienically sound methods of cleaning itself: hermetically sealed receptacles for refuse, tightly closed carriages for their removal, and as complete and rapid neutralization as possible by converting the organic part of refuse into mineral matter. Furthermore, from the standpoint of hygiene, as well as the labor protection of workers engaged in cleaning, it is necessary to strive for the fullest possible mechanization of all methods of refuse processing. The practice of cities abroad shows that cleaning is set up satisfactorily only in those places where it is the same function of municipal self-government organs as other branches of the municipal, urban economy (water supply, sewerage, transport). The worst results are produced by the concession system, under which the city outsources the production of cleaning to a concessionaire under certain conditions. Finally, leaving cleaning in the hands of individual private organizations, household ownerships, and private individuals leads to the worst results. Therefore, the immediate task of sanitary supervision and municipal economies is the organization of municipal cleaning in all cities of the Union. A necessary condition for its implementation is the presence within the system of municipal economies of a special organ that would manage cleaning and be responsible for it. In addition, it is necessary to have mandatory regulations that make the population's recourse to this organ for the provision of this type of municipal services mandatory, i.e., creating a monopoly right for the municipal economy on the one hand, and on the other hand, placing corresponding obligations on it. Such a system of municipal cleaning is possible only where municipal economies possess sufficiently powerful technical means to carry out this obligation. Cleaning of properties and yards. Of all properties without exception, solid refuse and garbage (see) are subject to removal, and in unsewered ones—in addition, also liquid refuse: filth and slops (see Scavenging, Cesspool, Closets). In a sanitary respect, out of all existing systems for removing solid refuse, preference should be given to daily garbage removal according to the exchange-container system. Such a system requires the construction of unloading stations at which the exchange of bins, washing, and their disinfection take place, as a result of which it is more expensive than other systems. In addition to the exchange-container system, the use of carriages ensuring dust-free transfer of garbage from the receptacle to the body of the carriage fully satisfies sanitary requirements. Both systems assume the installation in properties of portable metal receptacles, lidded bins with a capacity of 80 to 120 liters (details of these systems—see Garbage). Various types of traction are used for garbage transport: horse-drawn, automobile, electric locomotives; tramways and transport by water and railroad are also used. The type of traction has no sanitary significance; it is only important to technically ensure dust-free garbage transport guaranteeing against its spilling along the road, the absence of stench, etc. The further fate of refuse consists in its neutralization either by means of incineration (see Garbage Incineration), or by the soil method, or according to the "Beccari" system in thermal chambers in which garbage ferments and decomposes, turning into fertilizer (see Garbage). At the present time, efforts are being made to utilize garbage to the maximum extent. This is achieved by striving to sort out the valuable parts of garbage from the general mass either in houses before its removal or at central garbage-utilization stations. In the first case, instead of one, two or three collectors are installed at the collection sites—depending on whether only recyclables or also food waste for livestock feed is collected separately. At garbage-utilization stations, garbage is passed through a conveyor, with paper being sucked out by a strong exhaust fan, metal parts separated by means of an electromagnet, and the rest (bones, rags, glass, etc.) picked out by hand. Garbage is also sifted to separate fines going into fertilizer or for the manufacture of construction materials. Furthermore, garbage can be used by laying it in hotbeds or converting it into valuable fertilizer by composting.

The schedules for the removal of solid waste must be minimal: preferably daily or every other day, but no more than 5-7 days, keeping in mind the breeding periods of flies. The cleaning system for unsewered properties must consist of the construction of impermeable receptacles: cesspools and sink-pits (see Cesspool, Sink-pit). Systems of privies with peat backfilling are also permissible. Timely cleaning (at least once a month) of cesspools and sink-pits and the removal of sewage in specially equipped vessels, most preferably pneumatic ones (see Scavenging), must be ensured. The disinfection of sewage is carried out by plowing it into sewage disposal fields, as well as by processing it into fertilizer. For the latter purpose, peat can serve, upon mixing with which peat-fecal matter is obtained (see Utilization). Finally, for the cleaning of unsewered properties, a mixed system is also used, in which sewage is removed in barrels to so-called discharge stations (see), from where it is discharged through the general sewerage system to the treatment facilities of the latter. The cleaning of streets and squares consists in the removal of sweepings and dust from the pavement and sidewalks. Impermeability and smoothness of the pavement are two fundamental qualities that make it possible to properly organize cleaning. The best cleaning is permitted by improved pavements, which include all types of asphalt, cobblestone, clinker (see Paving). All these types of improved pavements make it possible to mechanize street cleaning, which is not permitted by imperfect coverings: cobblestone, macadam. Of great importance for combating dust is the construction of stone pavement joints. For the purposes of street hygiene, it is necessary to require the sealing of joints with bitumen or cement. It is also necessary that streets be provided with gutters, because only in their presence is proper washing of the street possible. Good gutters, correct gradient and profile of the streets do not allow water to stagnate on the pavement surface. Organization of cleaning is of great importance. The worst cleaning results are obtained in the case where the cleaning of a thoroughfare is the responsibility of the adjacent homestead. This system does not make it possible to mechanize the very process of cleaning, since the corresponding machines are expedient to use only along the entire length of the thoroughfare.

Figure 2.

This system also does not ensure simultaneous cleaning, which deprives the measures on the part of individual homesteads of significance. In the cities of the USSR, a mixed system of cleaning is used, in which the cleaning of only certain thoroughfares (squares, embankments, bridges, boulevards, etc.) is the responsibility of communal utilities, while the remaining thoroughfares are cleaned by house administrations. Sidewalk cleaning usually remains the responsibility of the house administration under all systems.

Figure 3.

For the collection and temporary storage of street sweepings on streets, above-ground receptacles (in the form of metal or wooden boxes) (see Incineration) or underground-type receptacles are arranged. The latter deserve preference, as they do not clutter thoroughfares, are convenient for dumping sweepings, and do not spoil the appearance of the street. The sweepings in this case fall into removable boxes, which are lifted upwards by means of a special device on a truck and removed to the unloading site (Fig. 2). To collect litter (paper, cigarette butts, etc.) on sidewalks, trash cans are installed. For manual street cleaning, ordinary brooms and dustpans for carrying sweepings are most commonly used. Smooth pavements allow street washing with mops, special rubber squeegees 503

CLEANING OF POPULATED AREAS

Figure 4.

moisten the pavement surface, and the sweepings themselves are picked up from the brush into the body, as a result of which no dust is produced during their operation. Brushes for washing and sweeping are made of piassava or metal. These brushes wear out quickly and frequently require replacement. The productivity of such machines is very high - from 8,000 to 15,000 m² per hour. With manual cleaning, productivity does not exceed 2,500 m² per worker in summer and 1,250 m² in winter. In addition to the daily removal of sweepings from the pavement, the application of special measures to combat dust is usually required. In its simplest form, this is achieved by ordinary watering with water, which is carried out either from fire hoses or using watering carts. The best results are given by the use of watering tank trucks (Fig. 5), which give a very

Figure 5.

high productivity: up to 75,000 m² per hour. A good effect is produced by the use of certain chemical agents for watering pavements, among which can be named: 1) calcium chloride, which possesses hygroscopic properties, as a result of which the pavement surface is maintained in a moist state for a long time; it is used in solutions of various strengths (e.g., 1 kg of CaCl₂ per 2 liters of water; from 0.33 to 0.40 of calcium chloride is required per 1 m² of pavement). For this purpose, so-called technical fused calcium chloride is used, which is a waste product of the production of soda, acetic acid, and some others. When experiments were carried out in Moscow, it proved sufficient to use it no more than 4 times in a summer; in between, the pavement is watered with clean water 1 time per day; at the same time, the pavement remained wet round the clock; the application cost is about 25 kopecks per 1 m² in a summer. 2) Various emulsions, the purpose of which is to bind dust on the pavement without letting it rise, are of great application abroad. In the USSR, experimental tests were carried out by the Oil Institute in Moscow, which yielded good results. The composition of the emulsion prepared by it includes bitumen, technical vaseline, ammonia, and water. According to foreign data, treating the surface with the emulsion 2-3 times a year is considered sufficient to obtain complete dust suppression. 3) Bitumen and bitumen-tar are used mainly for treating the surface of highways (tarred highway, see Paving) and cobblestone pavement. There are very many methods of tar-coating. An important matter in the improvement of populated areas is the issue of combating snow and ice slick in winter. This issue is important primarily in connection with the task of regulating street traffic. Indirectly, it also affects sanitary improvement (removal of contaminated snow, the danger of soil swamping in spring when snow melts). The commonly used method of removing snow to snow dumps by horse-drawn transport cannot be recognized as rational: it requires the use of a large number of hands to rake snow into piles, load it into carts, and transport for its removal. Snow dumps, which are usually arranged within the city limits, on the banks of rivers, etc., by spring turn into accumulations of huge masses of contaminated snow and ice crusts, which melt very slowly and sometimes do not manage to melt before the next winter. The rationalization of this business consists in the use of a) snowplows that rake snow to the side and clear the pavement; b) machines for loading snow into trucks, and c) melting it in special snow melters. Based on a number of observations abroad and in the USSR, for snow melting it is possible to use heat from waste waters (bathhouse, industrial); one can also recommend the use of snow melters of the Finnish type, an example of which can be the snow melter of the «Fenia» system. To combat ice slick, chipping of ice using manual or mechanical picks, sprinkling the pavement and sidewalks with sand and ash are used. Cleaning of collective and state farms. Particularly, it is necessary to emphasize the new task that has come to the fore in connection with the collectivization of agriculture and the creation of large agro-settlements - the removal and disinfection of waste in rural-type populated areas. In them, cleaning must be built inseparably with the task of utilizing all types of waste in agriculture: garbage, sewage, and manure as a source of heat for hotbeds and fertilizer, and food waste as animal feed. As receptacles for waste in such settlements, one can recommend privies arranged over manure storage facilities or at cattle yards, then privies with backfilling of sewage with peat, earth, etc. For large public buildings and dormitories, flush-closets are also quite applicable. Household waste and garbage, with the exception of those used for animal feed, can be collected in compost heaps for decomposition or used for stuffing hotbeds together with manure. The system of privies over manure storage facilities, where sewage is mixed with manure, peat or earth flush-closets, as well as the composting of sewage and garbage, significantly facilitate the removal of waste, which can take place in this case under incomparably more sanitary conditions than usual from cold privies and sink-pits. The disinfection of waste, carried out in the process of utilization in agriculture, also cannot cause objections from a sanitary sanitary standpoint, since the pre-rotting of waste in hotbeds, composts, as well as plowing them into the ground with proper management of the business are measures that fully meet the interests of hygiene. Some doubt is caused by the use of waste in agriculture from the helminthological side, as a result of which workers in such farms should be well instructed regarding compliance with sanitary rules: washing hands, washing vegetables, etc.