Focus
Rural Waste Disposal Problems - Case in Point: San Carlos, Nicaragua

by Christoph Ewen

Today, San Carlos is the capital of Rio San Juan department (Zone Especial lll) in the extreme south-eastern corner of Nicaragua. The town itself has a population of 5,000, and some 20,000 people live in the department as a whole. Most of the rural inhabitants live in asentamientos, villages in which the once-scattered neons have become concentrated.

Prior to the 1979 "triunfo" - the Nicaraguan revolution - this region and its economy were practically isolated from the rest of Nicaragua. Indeed, it maintained closer ties with Costa Rica than with Nicaragua. Schools, medical care and jobs were correspondingly scarce, even more so than in the rest of this "underprivileged" country. After the revolution, a number of ministries and major public enterprises set up regional offices in San Carlos. This resulted in a strong influx of trained man power from the Pacific area. As in the rest of the country, public literacy and health campaigns were launched.

In the past two years, the central government has delegated more and more competences to the municipalities as a result of economic difficulties. Consequently, the city administrators are now able to attend to their own community matters such as urban planning and waste management, and the engineering department is being expanded with additional junior staff.

Terms of References

Prior to the author's departure, his task was formulated as the exploration of " resource-conserving " waste disposal options.

Upon his arrival, however, the scope of objectives began to broaden quite rapidly: obvious problems such as the appalling hygiene in the barrios escondidos (shanty towns) and out in the country have been given high priority by the local public health authorities.

Thus, maximum importance is attached to the efficient disposal of refuse (including excrement). There is no appropriate handling whatsoever of hazardous waste. Used oil, refuse from hospitals and old car batteries constitute a real menace to man and the environment. The extension of the terms of reference led to a reconsideration of present practices in the storage of hazardous substances (agricultural chemicals, oils, petrol etc.).

Recycling potential in San Carlos

A waste analysis by the simplest of means reveals a refuse composition that is probably typical for rural regions in Latin America: roughly 70 per cent of the refuse collected consists of organic (vegetable) waste; the remainder is made up of metals, plastics, paper/card board, glass and leather/textiles. The metals and plastics content is remarkably high, while hardly any glass is found. With the exception of obviously worthwhile items, no used materials whatsoever are salvaged from the waste. There are no scavengers, i. e. people who collect salvageable material at the municipal dump, in San Carlos.

The reason is quite simple. The recycling of waste material in the form of plastic, paper or metal would be uneconomic for garbage collected in San Carlos. To be profitable, recycling operations require a certain minimum population density. In addition, it would simply be too expensive to transport the salvaged material from San Carlos to the Pacific region.

The only worthwhile form of recycling is the composting of organic material. While no farming is done in the immediate vicinity of San Carlos,the soil is so low in nutrients that compost could be very useful in public parks and private vegetable gardens. Moreover, it is precisely the organic materials that are the root cause of the pollution that emanates from dumps and landfills. Fires, biodegradation and the feeding habits of rats and birds cause the germs and pollutants contained in the garbage to be spread over a large area. Minimizing the organic fraction would therefore make good sense, helping to improve standards of health and hygiene and conserve the environment.

It was suggested that a composting experiment be conducted with market refuse, which consists almost exclusively of organic material. Such a measure would combine well with the night-soil treatment component of the water and sanitation project.

Waste-disposal planning

With a view to improving waste disposal (collection and dumping), the basic principles of problem oriented planning were elaborated in cooperation with the director of municipal services. The goal was not to force through short-term solutions, but to work towards an increased awareness of the problem on the part of the municipal services staff.

Collection of domestic waste

In most neighborhoods with paved streets, household refuse is picked up at regular intervals by tractor and trailer. No garbage is collected in the barrios partly because of escondidos, the poor condition of most roads there. Wherever no regular collection is provided for, unauthorized garbage dumps appear. They constitute a permanent risk of infection, mainly because of the freely-roaming pigs. Access to the shanty towns was improved during the author's stay.

Collection of hazardous waste

In San Carlos, hazardous waste consists mainly of refuse from hospitals, used oil and lead plates from worn-out truck batteries. While recommendations concerning hospital refuse must necessarily include wording to the effect that it should be collected in sealed containers, toxic waste solutions had to be worked out on a case-specific basis. On the premises of the town's biggest construction company, for example, huge numbers of damaged lead plates have accumulated. Since the plates are made of pure lead, it would be better from an ecological point of view to melt them down instead of having them gradually erode away into the groundwater. Therefore the old lead plates should be returned to the company that supplies the new ones. In the case of used oil, it would appear more appropriate to use it as fuel at the brickyard than to continue the present practice of "incineration in open drums", "soil infiltration" and "power-saw lubrication".

However, this only holds true for motor and transmission oil. Spent industrial oils with their high chlorine content should not even be used for firing brick kilns.

Search for a new dump site

The present municipal dump is too close to agricultural and industrial areas and to the groundwater level. Furthermore, there is no technical equipment whatsoever for reducing pollution. A new site was proposed that is several metres above the water table and has a relatively impermeable substratum, but at a location that increases the transport distance by several kilometers over bad roads. Accordingly, the first thing to do is repair the access road in order to go easy on the tractor. The disposal facility should have at least the following: a fence, gravel-filled ditches, regular compaction and final covering of full sections.

Latrines

Apart from the old center of San Carlos, there are no sewerage systems at all in the region. Nor would it be appropriate to lay more sewers. In the newer parts of the town and out in the country simple latrines are used. Though ordinary latrines are inappropriate for much of the region, because they tend to overflow due to high groundwater levels during the rainy season, the "latrine campaign" continues. It was suggested that a few dry latrines be built on a trial basis. Then, if the results were positive, the entire area could eventually be equipped with such latrines.

Storage of hazardous substances

There is a remarkable lack of concern regarding the storage and use of hazardous substances.

Despite what happened in Rama, where a hurricane destroyed the agriculturai chemicals storage facility and contaminated its surroundings, the equivalent facility in San Carlos is a wooden hut built on piles over the river bank. A recent inventory showed its contents to include six to seven tons of hydrocarbons, some chlorinated, among them the known mutagen gramaxon, in addition to 2,4-D and 2,4,5-T (chlorinated aromate swith a high potential for forming dioxin at high temperatures, e 9. in a fire) and even bacillus thuringensis. In 1984, San Carlos itself probably just barely missed a catastrophe when a fire destroyed practically every building on the bank of the river except the hazardous-substances hut.

The storage facility for antimalaria insecticides, also a wooden hut, constitutes an additional hazard. Whenever the liquid is transferred from one container to another, considerable amounts of it spill over and trickle through the floor planks and into the soil. Something must be done about this as soon as possible, because the community's most productive well is located nearby. With regard to groundwater protection and fire prevention, the conditions of oil and petrol storage in the San Carlos area are inadequate.

The municipal authorities of San Carlos must, in their building supervisory function, insist on getting the present situation improved. According to the impression gained by the author, the municipal and regional political decision-makers are interested in finding solutions to the above problems. However, the relevant comments and observations were seen to apply only to the storage, not to the transport or use of hazardous substances. Without doubt, the people must be made more aware of the problems involved in the use of agricultural chemicals and anti-malaria insecticides, including appropriate protection for those handling such agents.

Conclusions

Abstract

For the small Nicaraguan town

San Carlos (population 5,000), disposal. of domestic and industrial waste is a major issue. Recycling is not worthwhile because it is too expensive to transport the waste to appropriate industrial centers in the pacific region. The only form of recycling possible is composting of the organic waste, which accounts for 70 per cent of the total. In future, organic and inorganic waste are to be collected separately. In addition, the existing dump is to be improved and a suitable site found for a new one. Safe disposal of hazardous chemicals is a further priority for the future.

Résumé

Pour la ville nicaraguayenne de San Carlos, I'elimination des ordures ménagères et des déchets industriels revêt une importance capitale. Pour cette ville de 5000 habitants, le recyclage de vieux matériaux est dépourvu d'intérêt, car le transport vers les usines de traitement situées prés du Pacifique est trop onéreux. Seuls les déchets organiques (70%) peuvent être compostes. A l'avenir, I'enlèvement des ordures ménagères et celui des autres déchets sera effectue séparément a San Carlos. Par ailleurs, la décharge existante doit être améliorée, et un site mieux approprie devra être trouve pour en créer une autre. Le stockage sûr de produits chimiques dangereux est un autre,probleme à résoudre.

Extracto

Para la ciudad nicaraguense de San Carlos la eliminación de las basuras domiciliarias e industriales tiene una capital importancia. El reciclaje de materiales viejos no es rentable pare esta cuidad de 5.000 habitantes, pues el transporte a las plantas de reciclaje en la región del Pacífico es demasiado costoso. Solo los desechos orgánicos, un 70 por ciento del total de desechos, pueden convertirse en compostage. En el futuro en San Carlos las basuras domiciliarias y las basuras especiales se recoge ràn por separado. Ademas se va a mejorar el basurero existente y se buscarà un lugar apropiado pare otro nuevo. EI futuro almacenamiento seguro de productos químicos peligrosos es otros de los problemas a resolver.