[pt] A água potável não existe mais em abundância. É preocupante verificar que o desperdício e a contaminação dos recursos hídricos ainda sejam práticas recorrentes, mesmo diante de evidências pessimistas acerca de sua disponibilidade, como observado no local escolhido para o desenvolvimento desta pesquisa. Portanto, este trabalho tem como objetivo apresentar soluções para evitar a contaminação do sistema de abastecimento, recomendar equipamentos de saneamento, sugerir um esquema de drenagem que não favoreça a proliferação de vetores de doenças, propor uma estratégia para o manejo adequado dos animais domésticos e garantir o fornecimento de água verdadeiramente potável na vila de Tanahbala, na Indonésia. O desenho metodológico está alinhado aos pressupostos da pesquisa exploratória, com a apresentação do diagnóstico local, para posterior análise quantitativa por meio da aplicação de um software de modelagem matemática, denominado Modflow 2000, versão 4.2.0.1.5.1. A ferramenta foi utilizada para visualizar o fluxo dos contaminantes no lençol freático e estimar a concentração dessas substâncias na fonte de abastecimento da vila, para posterior apresentação das sugestões de melhoria. Como resultado do diagnóstico local e dos níveis numéricos de contaminação, foi possível observar que as causas desses problemas estavam ligadas ao esgoto doméstico, à criação desordenada de animais e à proximidade de um cemitério. Sugeriu-se então algumas soluções como a realocação dos poços para captação de água, a construção de cisternas para captar água da chuva, a utilização de liners e de uma camada de geomembrana, o manejo dos dejetos da criação de animais, drenagem e soluções de saneamento. / [en] Potable water has become increasingly scarce. It is no longer an infinitely renewable resource as we once thought it was. However, it is not unusual to see hydric resources being wasted or contaminated – despite all the pessimistic forecasts regarding its availability for the future generations. Actually, lack of water is not a far-fetched problem anymore. Around 1.6 billion people rely on insufficient hydric resources. By 2020, this number will double: there will be about 3 billion people with insufficient access to drinking water (Boff, 2005). The central theme of the present research deals with the problems provoked by an inefficient management of hydric resources. Its aim is to provide alternatives for managing water in the small and remote village of Tanahbala, in Indonesia. In this distant town, solutions which might be feasible elsewhere do not always prove to be possible. In order to provide potable water for the villagers in Tanahbala, it is crucial to overcome three main obstacles: 1) the inappropriate disposal of domestic sewage; 2) the lack of livestock management; and 3) the contamination provoked by a neighboring cemetery. So as to address these problems, the present study has pointed out a few measures, such as the replacement of water wells, the construction of tanks for catching and storing rainwater, the use of liners and a layer of geomembrane, the appropriate management of the animals excrement, as well as many other sanitary solutions. All these recommendations attempt to meet the village s needs without requiring a sophisticated infrastructure – which is not within the villagers reach at the present time. According to data from the World Health Organization (WHO) and UNICEF (2004), 1.1 billion people around the world do not have access to pure water. In the meantime, 2.6 billions do not live in areas with adequate sewage. Tanahbala, the place studied in this research, is just one more item in the apparently endless list of locations deprived from essential resources such as water. The troublesome water distribution and sewage treatment has a significant impact on mortality rates. All over the world, from four to six thousand children die everyday because of diseases associated to the lack of potable water or inadequate sewage treatment (WSSCC, 2011). In Indonesia, an impressive number of people live below the poverty line. In these lower social layers, the lack of potable water remains the most prominent health problem. The reasons behind this problem are the geographic aspects of Indonesia and the precariousness of the infrastructure used to distribute water. Quite differently from continental areas, Indonesia does not have the means to create a centralized water distribution system. Formed by thousands of islands, the country has to delegate to each one of them the management and the treatment of hydric resources. This is the reason why the population of Indonesia has suffered from a number of diarrheic diseases caused by contaminated water. No wonder diarrhea is still ranked among the ten main causes of deaths in Indonesia (WHO/ UNICEF, 2004). In fact, chronic infectious diarrhea has been detected in 66.7 per cent of the population. Based on this information, it is unavoidable to come to the conclusion that both, the treatment and the distribution of water in Indonesia, are quite far from the minimum security standards. Hence, it is clearly urgent to develop strategies to meet the population s needs, especially in the most distant islands, where potable water is still a far-fetched dream. In Indonesia, underground water is normally good from a microbiological viewpoint. The problem is that it is easily contaminated due to the emission of pollutants from homes, factories, plantations and even cemeteries. The present research focuses on specific types of water pollution: the contamination provoked by cemeteries, livestock and domestic sewage. The first part of this research has been developed by means of observing the region and collecting documents on the governmental database, so that the local characteristics could be thoroughly understood. The methodological design adopted, therefore, is in line with what is called exploratory research.
In the engineering field, exploratory research is particularly useful when it is necessary to estimate the feasibility and the costs of a given project. The scope of the present research is precisely that: the aim is to provide a solid ground for the development of future research that might work on a more definite solution for the hydric resources in Tanahbala. First, this research presents a diagnosis of the local situation. Afterwards, a quantitative analysis is carried out with the help of a mathematical modeling software called Modflow 2000, version 4.2.0.1.5.1. This tool has been used to visualize the flow of contaminants in the underground water, as well as to estimate the concentration of substances in the water supply used by those who inhabit Tanahbala. In the end, this study recommends some improvements, without disregarding the limited resources and the precarious infrastructure available in the village. The inappropriate location of the cemetery and the careless management of livestock are not the only threats to the quality of the soil and the water in Tanahbala. The population is also used to bathing in public water sources, which certainly worsens the contamination problem. Raw sewage and animals surround the village, forming a single nucleus of contamination. The cemetery is on the left side of the entrance of the village. In addition to that, the well that supplies water to Tanahbala is dangerously close to the contaminated areas. Occasional earthquakes and tsunamis add chaos to a situation which is already quite precarious. In 2004, Indonesia was hit by a devastating tsunami, whose tragic effects were also felt in Tanahbala. A great part of the village lies on a type of soil that is mostly sandy, favoring the penetration of pollutants, due to its high permeability level. This characteristic increases considerably the risks of underground water contamination. The toxic fluids that come from the decomposition of corpses are the main cause of environmental pollution provoked by cemeteries. The crucial challenge is to stop them fluid from infiltrating into the soil and contaminating underground water. Liners are layers of low permeability formed by natural, artificial or a combination of both materials. The objective of these layers is to protect a given area from the infiltration of harmful fluids. One of its essential features is also the capacity of removing impurities. The use of liners is very common in sandy soils, where their efficiency is out of question. When used in this type of soil, the liners manage to reduce significantly the permeability level. Moreover, it is a low cost alternative, since it does not require the employment of higher technologies. The combination of these characteristics seems to point out the use of liners as the ideal option for protecting the inhabitants of Tanahbala against the hazardous substances that come from the cemetery. Geomembranes may also be an important ally. They are impermeable synthetic barriers, quite resistant from a physical and chemical point of view, and with low hydraulic conductivity. They are commonly used to stop leachate from migrating into the soil or underground water. Because they are susceptible to flaws, geomembranes should not be the only mechanism of protection. It is fundamental to rely on a more complete system of isolation. Taking into account the peculiarities of the Indonesian context, the present research recommends the use of a geomembrane and a liner formed by soil, cement and quicklime. Domestic sewage contains pathogens that cause several diseases, such as typhoid, infectious diarrhea and amebiasis. In Tanahbala, sewage is generally left on the soil, contributing to the dissemination of a wide variety of diseases. Besides, both superficial and underground water quality tends to be altered by this kind of contamination. The main consequences are a change in the color and in the smell of water, as well as a considerable reduction in the concentration of oxygen. The water pollution triggered by the lack of adequate sewage treatment is also harmful for the local environment, putting at stake the survival of animals and vegetation in the Indonesian village. The position of the wells in relation to the main points where contamination by sewage happens is also a fundamental aspect. In Tanahbala, the wells that provide drinking water for the houses are dangerously located downstream in relation to the places where contamination occurs. The solution is
quite simple: repositioning these wells and placing them upstream is an essential step in order to improve the quality of the water available to the villagers. In addition, it is essential to construct a septic tank where sewage can be disposed and decomposed by anaerobic bacteria. The present research has used the Brazilian standards to suggest the measures for the Indonesian septic tank. However, in further studies, it is important to use local data to design the ideal system for the villagers in Tanahbala. Placing tanks to catch and store rainwater is an intelligent and inexpensive measure. With the high rainfall rates in Indonesia, this option seems to be very promising. As long as these tanks remain protected, the water stored by them is harmless. The choice of the material for the tank is also relevant. Cement lasts longer. However, if it is difficult to transport this material to Tanahbala, plastic tanks might be a better option. The construction of dungyards seems to be the most appropriate option for the population in Tanahbala. Besides presenting low costs, they are easily managed. The excrement kept in these dungyards remains there for 120 days. Throughout this period, organic matter becomes stable and the pathogens in it are deactivated. Composting is also a worthwhile alternative; after all, this process is able to reduce the bad smell and the proliferation of hazardous microorganisms. On top of that, composting turns useless ordure into a valuable commodity: manure, which is quite useful as a fertilizer. The main challenges regarding the use of composting have to do with handling three variables – humidity, aeration and temperature. The creation of an efficient draining system is essential and challenging at the same time. The first difficulty has to do with handling the rainwater that accumulates on the ground. When the draining system does not work properly, the population suffers from a number of problems, such as floods and diseases related to the uncontrolled accumulation of water: diarrhea, typhoid, leptospirosis and malaria are some of the illnesses that become widespread once draining is not efficient. In addition, humid soils provide a longer life for microorganisms. Thus, draining is an important tool when it comes to reducing the contamination of the soil by pathogens. In Tanahbala, specifically, it is recommended to adopt a microdraining system that combines three modalities: superficial, underground and vertical.Counting on appropriate equipment is not enough when the population is not aware of its environmental and sanitary responsibilities. Therefore, it is
fundamental to raise people s awareness on the importance of adopting new hygiene habits and helping protect the environment.
| Identifer | oai:union.ndltd.org:puc-rio.br/oai:MAXWELL.puc-rio.br:55567 |
| Date | 29 October 2021 |
| Contributors | EURIPEDES DO AMARAL VARGAS JUNIOR |
| Publisher | MAXWELL |
| Source Sets | PUC Rio |
| Language | Portuguese |
| Detected Language | English |
| Type | TEXTO |
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