Water Characteristics in the City of Novo Hamburgo and the Need of Rational Use of Water Resources

UNIVERSIDADE DO VALE DO RIO DOS SINOS - UNISINOS

HEALTH SCIENCES CENTER

BIOLOGICAL SCIENCES PROGRAM

Ana Carolina Klauck

WATER CHARACTERISTICS IN THE CITY OF NOVO HAMBURGO AND THE NEED OF RATIONAL USE OF WATER RESOURCES

São Leopoldo

2007

WATER CHARACTERISTICS IN THE CITY OF NOVO HAMBURGO AND THE NEED OF RATIONAL USE OF WATER RESOURCES

Ana Carolina Klauck ¹

Jackson Müller ²

ABSTRACT

Water is the most characteristic constituent of the Earth. An essential ingredient of life, water is perhaps the most precious resource the Earth provides to humanity. Although so much negligence and lack of vision regarding this resource can be observed across countries worldwide, human beings are expected to hold great respect for water, seeking to maintain its natural reservoirs and safeguard its purity. The future of the human species and of many other species may be jeopardized unless there is a significant improvement in the management of the Earth's water resources and in environmental education activities that help reduce waste and generate conscious consumption. Water resource management is possibly the environmental issue with the greatest integrating power, affecting every segment of society and cutting across the various uses of land, such as forest exploitation, agriculture, industry, and mining, among others. Based on these considerations, this study presents some characteristics of the water supplied to the municipality of Novo Hamburgo and the importance of the rational use of water resources, as well as the dangerous fluctuations among rainfall indices, industrial pollution, and uncontrolled consumption, which can be harmful to the population and the environment. Through research carried out together with the Municipal Sanitation Company (COMUSA), the elements present in raw water obtained from the Sinos River and the variables resulting from the treatment process were analyzed.

The quality of the supply water verified in the municipality of Novo Hamburgo has its physicochemical properties impaired by the discharge of sewage upstream of the intake point. Although the city's population has increased, the raw volumes consumed by the municipality show a reduction from 2003 to 2007.

Keywords: Water quality. Lack of water. Rational uses. Sinos River. Environmental Education.

________________________________________

¹ Undergraduate student, Biological Sciences Program - Health Sciences Center - Universidade do Vale do Rio dos Sinos, UNISINOS - P.O. Box 275, 93001-970, São Leopoldo, RS, Brazil

² Advisor - Professor, Biological Sciences Program - Health Sciences Center - Universidade do Vale do Rio dos Sinos, UNISINOS - P.O. Box 275, 93001-970, São Leopoldo, RS, Brazil

1 INTRODUCTION

Water is the most characteristic constituent of the earth. An essential ingredient of life, water is perhaps the most precious resource the earth provides to humanity. Although so much negligence and lack of vision regarding this resource can be observed across countries worldwide, human beings are expected to hold great respect for water, seeking to maintain its natural reservoirs and safeguard its purity. The future of the human species and of many other species may be jeopardized unless there is a significant improvement in the management of the earth's water resources (UNITED NATIONS DEVELOPMENT PROGRAMME, 2006; corrected from the original "MAURITS, 1989" citation, which had no matching reference-list entry — see revision note).

Almost all of the planet's water is concentrated in the oceans. Only a small fraction, less than 3%, is found on land, and most of that is in the form of ice and snow or below the surface (groundwater). Only a very small fraction, about 1%, is directly available to humans and other organisms, in the form of lakes and rivers, or as moisture present in the soil, in the atmosphere, and as a component of countless organisms.

Although Brazil still holds a privileged position in terms of water quantity — it holds approximately 12% of the world's surface water resources (FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, 2015; corrected from the 8% figure originally cited to MÜLLER, 2006, per revision note) — the way this water is used has not been correct or responsible. The destination of water in Brazilian households amounts to about 200 liters per day: 27% for cooking and drinking, 25% for hygiene (bathing, brushing teeth), 12% for washing clothes, 3% for other uses (washing cars, sidewalks), and, finally, 33% for toilet flushing.

Overexploitation, disregard for water sources, poor distribution, pollution, deforestation, and waste are just some of the factors that demonstrate the neglect of this important resource. It is important to emphasize that water scarcity endangers life on the planet and can affect various economic activities, including electricity generation.

Water resource management is possibly the environmental issue with the greatest integrating power, affecting every segment of society and cutting across the various uses of land, such as forest exploitation, agriculture, industry, mining, among others.

Studies conducted by the United Nations (2007) warn of a supply crisis that could affect several regions of the Earth in the coming years due to increased demand and the contamination threatening the planet's freshwater reserves. Lakes and rivers are turning into repositories for toxic industrial waste and chemical products used in agriculture. Agriculture, at times, contaminates 70% of the freshwater across the planet, making the water unusable for human consumption. Water-related diseases are estimated to kill a child every eight seconds, amounting to approximately 1.4 million child deaths per year (UNITED NATIONS WORLD WATER DEVELOPMENT REPORT 2, 2006; corrected from the original "more than ten million people" figure, which could not be traced to a specific source, per revision note).

There is not much current information available regarding water use. There is also a significant lack of information about water availability, particularly in the region studied. Inadequate procedures and a lack of interest from many institutions reflect the spread of water quantity and quality problems. It is necessary to highlight environmental education activities that help reduce waste and generate conscious consumption, through educational programs and campaigns to persuade people to adapt their behavior to the water cycle and to recognize that water is neither infinite nor free (MÜLLER, 2006).

Based on this information, it was decided to compile some characteristics of the water that supplies the municipality of Novo Hamburgo, such as the quality and the quantity the municipality consumes on average per year, highlighting the importance of the rational use of this finite resource essential to life on Earth.

This study aims to analyze some characteristics of the water in the municipality of Novo Hamburgo, highlighting the importance of the rational use of water resources in a comparative study of two neighborhoods of the city.

2 MATERIALS AND METHODS

To obtain data on water in the municipality of Novo Hamburgo, literature research and visits to COMUSA were carried out. These visits were conducted monthly in 2007 for data analysis and collection. Characteristics such as the quality and quantity of water consumed by the municipality were studied, also comparing water consumption between two neighborhoods of the city. Additionally, a compilation of geographic information on the Sinos River watershed and historical information on the city of Novo Hamburgo was carried out, as these influence the availability and consumption of drinking water.

Santo Afonso and Operário were selected for this neighborhood-level comparison because they represent contrasting positions relative to the sources of water contamination discussed in this study. Santo Afonso is located immediately upstream of and adjacent to COMUSA's water intake point on the Sinos River — the same stretch referenced in Section 2.1 with respect to residential and industrial discharges released above the intake pumps. Operário, by contrast, owes its name and historical development to Novo Hamburgo's footwear and leather industry, the city's traditional economic base, and sits within a zone of concentrated industrial activity. This pairing was chosen to compare a neighborhood associated with the raw-water catchment area against one associated with industrial/effluent-generating activity. [Rationale added in this revision, per author clarification — see revision note.]

2.1 Characterization of the Sinos River Watershed

The Sinos River watershed, located in the northeast of the State, between the 29° and 30° south parallels, covers an area of 3,820 km², corresponding to 4.5% of the Guaíba watershed and 1.5% of the total area of the State of Rio Grande do Sul. Its headwaters are located in the Serra Geral, in the municipality of Caraá, at an altitude of about 60 meters, running in an east-west direction to the city of São Leopoldo, where it changes to a north-south direction, flowing into the Jacuí River delta between the Grande dos Marinheiros and das Garças islands, at an altitude of 12 meters. Its main tributaries are the Rolante and Paranhana rivers, in addition to several streams. The Paranhana River receives water transferred from the Caí watershed, from the Salto, Divisa, and Blang dams.

The watershed's vegetation cover is greatly reduced, with the remaining vegetation located predominantly at the headwaters of the Sinos River and its tributaries.

The upper portion of the Sinos River (from Caraá to Rolante) has riparian vegetation and small wetlands. These are areas of low population density, with small rural properties whose agriculture is diversified, including rice, sugar cane, and various vegetable crops. Livestock farming is also not highly developed, but there are small dairy cattle, swine, and poultry operations. In the middle portion of the Sinos River (between Taquara and Sapiranga), population density increases, but the two large cities (Sapiranga and Taquara) are not located on its banks. This portion of the river does not have a character as rural as the upper portion. The main tributary of the Sinos River in the middle portion is the Paranhana River, which drains municipalities such as Taquara, Igrejinha, Três Coroas, and part of Gramado and Canela.

The lower stretch, from Campo Bom to the mouth at the Jacuí delta, has a high concentration of population and industry, where the main forming streams drain large urban centers, such as Campo Bom (Schmidt Stream), Novo Hamburgo (Pampa Stream and Luiz Rau Stream), São Leopoldo (Peão Stream and João Corrêa Canal), Estância Velha and Portão (Portão Stream), Sapucaia do Sul (José Joaquim Stream), and Esteio and the northern zone of Canoas (Sapucaia Stream).

The Metropolitan Region of Porto Alegre includes 21 of the 29 municipalities that make up the Sinos River watershed. In this region, 90.6% of the population occupied urban areas and 9.4% was in rural areas (INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA, 2006). Currently, the watershed is home to 1.6 million people, representing 17% of the State's total population concentrated in only 3.5% of its territory (HAASE, 2001). This watershed is bounded to the east by the Serra Geral and by the Caí watershed to the west and north, and to the south by the Gravataí watershed. Its main watercourse has an approximate length of 190 km and an annual rainfall of 1,350 mm.

In the upper part of the watershed, the terrain is more rugged, the river has rapids, and agricultural activities are carried out on small properties. As the river descends, population density and urbanization increase, as does industrial concentration, with the leather and footwear sector standing out. Only 8% of the population residing in the Sinos watershed is considered rural, and population density reaches as high as 2,468 inhabitants/km². Public water supply covers 93% of urban households, predominantly from surface sources. Despite this level of public service coverage, only 3% of the population is connected to the basic sanitation network, with 25% having no connection to any type of system and 72% relying on precarious local solutions. This situation is aggravated by the large quantity of hazardous industrial solid waste found along the Sinos River watershed. Daily waste production is 1,000 tons, and collection is carried out in 86% of households (INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA, 2000). Along the Sinos sub-watershed lies almost half of the Class I industrial solid waste — the most hazardous, due to containing heavy metals — found in the Guaíba watershed (PRÓ-GUAÍBA, 1998). This watershed still shows service levels higher than those of the State as a whole, considering aspects related to basic sanitation.

Sources of anthropogenic contamination are directly associated with domestic and industrial discharges and with leachate from landfills that contaminate the water with pathogenic microorganisms (FREITAS; ALMEIDA, 1998). In addition to promoting the mobilization of metals naturally contained in the soil, such as aluminum, iron, and manganese (NORDBERG; GOYER; CLAKSON, 1985), these sources are also potential origins of nitrate and organic substances that are extremely toxic to humans and the environment. Industrial pollution was once the main source of concern regarding water quality in this watershed, but with the implementation of treatment plants in industries, this situation has changed. The main sources of pollution are located in the middle and lower stretches and originate from domestic sewage. The growing informal settlement and disorderly occupation of the territory, especially in important preservation areas such as wetlands, also aggravate this situation. Livestock activities, in the areas where they are concentrated, also constitute a significant polluting source.

The waters of the Sinos River watershed ensure the continuity of life and promote the development of our region. Like every natural resource, they must be protected as best as possible from the impacts caused by our actions and used rationally, without waste (FEPAM, 2006).

2.2 Historical Aspects of the Study Region

In the 1930s to 1950s, the Sinos River still had good conditions for bathing and even for potability. Over time, at an increasingly accelerated pace, these conditions were altered as a result of population and industrial growth, with waste and sewage discharged directly into the river or into adjacent wetlands. In the municipalities through which the Sinos River cuts across the territory, within the floodable channel near the river, the native vegetation was typical of wetlands, including some larger trees such as willows, ingá trees, corticeira trees, and açoita-cavalo trees. In the higher areas, starting in the 1950s, eucalyptus planting began and spread inland, forming a homogeneous forest with trees of different heights and ages. Amid this forest, clearings emerged with very old trees that allowed the development of native species, including large fig trees.

Until the 1970s, the riparian vegetation was still dense or relatively dense, cut through by a few drainage channels and with some natural ponds or small dams, which only dried up during major droughts. There were no deep signs of depredation, with the exception of small tree cuttings for firewood, some episodes of illegal hunting, or clay extraction for potteries, which was carried out in areas without vegetation.

With regard to the wetlands, they have suffered a major impact along the entire length of the river since then. The impact was initially caused by the advance of farming, followed by numerous resorts in the municipalities bathed by the river and by urbanization through the removal of firewood for burning in bakeries, potteries, and industries. Later came infrastructure works and flood protection, with barriers, bridges, walls, pipelines, and buildings being built that led to the destruction of centuries-old trees. As these works enabled urbanization and eased flood risks, subdivisions began to appear, with houses built even within the water, bringing further deforestation and a reduction of wetland areas along the banks, driven by the rising price of lots with infrastructure. An invasion of highly urbanization-critical zones occurred, through the installation of shacks that expanded toward the river. As civil construction grew, so did mining in the higher sandstone areas, with the extraction of clay for potteries and medium-grade sand for making mortar for buildings (AVELINE et al., 1995).

Figure 1 - Location map of the Sinos River and the municipality of Novo Hamburgo (SEMAM, 1998).

2.3 Characterization of the Municipality of Novo Hamburgo

Located in the State of Rio Grande do Sul, the municipality of Novo Hamburgo is 40 km from Porto Alegre, the State capital. Situated in the Sinos Valley, it covers an area of 217 km² and has a population of approximately 236,193 inhabitants (2000 Census). It is bathed by the Sinos River, and its average annual temperature is around 19°C. Novo Hamburgo emerged in the first half of the 19th century, as a result of the German colonization of the State of Rio Grande do Sul. The first German immigrants arrived in Brazil in 1824, landing in São Leopoldo. They soon spread across various regions of the Sinos Valley, and a settlement emerged at Hamburger Berg, today the Hamburgo Velho neighborhood, which gave rise to the city of Novo Hamburgo. Several commercial establishments appeared nearby, and the social life of the settlers converged there.

In 1832 they founded their Evangelical worship community, and around 1850, the first tanneries, saddleries, and shoemakers' workshops appeared, supplying the Rio Grande do Sul province with their handcrafted products. Progress arrived for good with the opening of a railroad, which ended up drawing the settlement's commercial center to the area around its station. The industrialization of leather goods entered the community's life from the end of the last century onward. Electricity to power motors helped drive the region's social, cultural, and political progress.

Water supply covers most of the city and also supplies neighboring cities. Regarding storm drainage, the networks are well sized and distributed, reaching most of the population. The climate of the Novo Hamburgo region is subtropical. In the Agroclimatic Atlas (1989), some data on this region can be observed.

Average Annual Temperature: 19.4 °C;
Seasonal Rainfall: Summer (385 mm); Autumn (355 mm); Winter (378 mm); Spring (341 mm);
Highest rainfall in 24 hours: 143 mm;
Relative Humidity: Average 76%
Winds predominantly come from the eastern quadrant and secondarily from the western quadrant. Storms predominantly come from the southeast.

2.4 Characteristics of the Santo Afonso and Operário Neighborhoods

The Operário neighborhood is located to the north of the Municipality of Novo Hamburgo. It covers a geographic area of 2.10 km², 2.74% of the municipality’s area. It has a population of 4,350 inhabitants (INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA, 2000) and 1,041 connections to the drinking water distribution network (COMPANHIA MUNICIPAL DE SANEAMENTO DE NOVO HAMBURGO, 2007). Its neighboring districts are: to the north, Roselândia; to the east, Vila Nova and Guarani; and to the west, Rio Branco and the municipality of Estância Velha. The first large buildings built were the General Hospital and the technical school (SENAI). At the time, there was a single street linking the neighborhood to downtown. Vegetation cover was extensive. The neighborhood progressively grew, and today it has numerous paved streets, squares, and gardens. It was named Operário ("Worker") because it was settled by numerous workers who came looking for jobs in Novo Hamburgo's growing footwear industries ([MATÉRIA PUBLICADA], 1998).

The Santo Afonso neighborhood is located to the south of the municipality of Novo Hamburgo. Two-thirds of its area is part of the special environmental preservation zone, with wetland areas. It covers an area of 8.60 km² with a population of 19,394 inhabitants (INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA, 2000) and 7,550 connections to the drinking water distribution network (COMPANHIA MUNICIPAL DE SANEAMENTO DE NOVO HAMBURGO, 2007). It represents 12.61% of the municipal area. It borders the Rondônia neighborhood to the north; the municipality of São Leopoldo to the south; the Canudos neighborhood to the east; and the Industrial and Liberdade neighborhoods to the west. There is a predominance of low-income population. It had a population increase of 137.45% from 1980 to 1995. In terms of population, Santo Afonso is the neighborhood that grew the most over the last fifteen years. The neighborhood concentrates a strong industrial and commercial network, with tanning industries, footwear components, machinery, rubber and plastics industries, window/door frames, furniture, and leather goods (SCHÜTZ, 2001).

2.5 Characterization of Water Supply by COMUSA

Water supply in the city of Novo Hamburgo is provided by COMUSA. On December 20, 1989, the Municipal Government of Novo Hamburgo (2007) created a mixed-economy company, with the goal of significantly improving the population's quality of life and managing the basic sanitation system (drinking water supply and sewage in the municipality). Today, it produces an average of 1.7 billion liters of water per month, to supply an average of 50,000 active connections (across 97% of the city's urban area).

In drinking water distribution systems, water quality can undergo a series of changes, causing the water at the user's tap to differ from that which leaves the treatment plant. Such changes can be caused by chemical and biological variations or a loss of system integrity (DEININGER et al., 1992). Some factors that influence these changes include: (1) the chemical and biological quality of the water source; (2) the effectiveness of the treatment process, reservoir (storage), and distribution system; (3) the age, type, design, and maintenance of the network; (4) the quality of the treated water (CLARK; COYLE, 1989).

2.6 Results and Discussion

The water quality data used in this study were generated from information from the Monitoring Network of the Fundação Estadual de Proteção Ambiental (FEPAM), operating monthly since 1990. Consumption data obtained from research conducted at COMUSA were also used.

The Water Quality Index adopted uses the following quality ranges:

SCORE	RATING
0 to 25	Very Poor
26 to 50	Poor
51 to 70	Fair
71 to 90	Good
91 to 100	Excellent

Table 1 - Water Quality Index (WQI) ranges, adopted by the NSF-National Sanitation Foundation.

2.7 Water Quality Index of the Sinos River

Graph 1 – Water Quality (annual values) at the Sinos River/RS monitoring sites

2.8 Water Distribution: Active Connections in the Municipality

Graph 2 – Active Water Connections in the Municipality of Novo Hamburgo from 2003 to 2007

2.9 Water Distribution: Volume Consumed in the Municipality

Graph 3 - Volume Consumed in the Municipality of Novo Hamburgo from 2003 to May 2007

2.10 Water Distribution: Volume Consumed in the Santo Afonso Neighborhood

Graph 4 - Volume consumed (m³) in the Santo Afonso Neighborhood from January/2006 to June/2007

2.11 Water Distribution: Volume Consumed in the Operário Neighborhood

Graph 5 - Volume consumed (m³) - Operário Neighborhood from January/2006 to July/2007

The analysis of the qualitative data collected annually (Graph 1) indicated a decline in water quality in several municipalities in 2005 and 2006. This decline may be related to the droughts that occurred in those years (INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA, 2006). During drought periods, the river's volume undergoes a drastic reduction: its flow drops from 71,000 l/s to 2,900 l/s, and this situation tends to worsen during prolonged droughts. Regions of high urban concentration suffer the worst consequences from the constant variations in the river's water level, both during flood and drought periods. Thus, quality losses coinciding with droughts suggest that water quality is not always linked solely to prevention and treatment policies, but is also susceptible to natural characteristics, such as rainfall indices. This association also warns that a deficient sanitation policy, in a drought year, could be much more serious.

The upper stretch, from the headwaters of the Sinos River in Caraá to the locality of Santa Cristina, shows a predominance of quality scores between "Fair" and "Good," with scores ranging from 51 to 75. The scores remain in the "Fair" range up to the Novo Hamburgo intake (bridge to Lomba Grande), but it is noted that the values of these scores decrease along the course of the river. It can be observed that up to this point, quality shows a gradual decline, consistent with the cumulative polluting contribution of each city.

In the middle stretch, the mouth of the Luiz Rau Stream, which drains the central area of Novo Hamburgo, shows waters with average quality in the "Poor" range, some of the lowest scores on the graph, around 30. This segment shows the worst quality observed in the graph. Perhaps the industrial effluent treatment requirements were not being fully complied with, or at least not at all times, with companies releasing untreated effluents during periods of lower inspection. Another cause to be considered would be the contribution of sewage, drained intentionally or accidentally — through the storm drainage network — by the Luiz Rau Stream.

The next stretch, from Novo Hamburgo to São Leopoldo, including the João Correia Canal, is in the "Poor" range, but shows no downward trend in quality, and average scores range between 40 and 50. It is important to note that there is a subtle improvement in quality compared to the poor values of the previous area, which may indicate that the river dilutes and biodegrades part of the damage suffered previously. This slight improvement may be a subtle indicator that the river is capable of recovering from certain impacts, provided it does not receive another input of pollutants in a stretch immediately following a polluted effluent.

In contrast, the mouth of the Portão-Estância Velha Stream (draining about 40 tanneries from these cities) shows a further decline in quality, trending toward the "Very Poor" range (below 25). This significant decline may indicate that these companies have contributed negatively to the water quality of the Sinos River, the same water source for the municipalities it bathes, since there are intake pumps interspersed with these tributaries. It is hoped that the effluent treatment at these companies will be able to control the possible emission of heavy metals such as lead, chromium, and mercury, used in dye fixation and leather treatment, as well as aluminum, recently identified as a possible vector in Alzheimer's disease, according to Takashima (2007), for example. Other studies have linked mercury and other metals present in the water to certain diseases (SHCHERBATYKH; CARPENTER, 2007).

The final stretch, between Sapucaia and the mouth of the Sinos, shows quality ranging between "Poor" and "Fair," with no downward trend. It should be noted that despite the "Fair" rating at the end of the observed stretch, comparison with previous segments indicates a slight improvement in quality, once again suggesting that there is still viable potential for the river's recovery, provided there is no new impact for some distance along it. Therefore, the worst scores were found near the Luiz Rau and Portão streams.

The data in Graph 2 show that from January-May 2003 to the same period in 2007, there was a 6.23% increase in the number of active water connections in the municipality of Novo Hamburgo. This could indicate a risk of increased consumption due to population growth, but the data in Graph 3, described below, show otherwise. (This is a simple period-over-period comparison of the underlying monthly values; formal significance testing was not performed, as the raw monthly dataset was not available for this revision — see revision note.)

According to the data in Graph 3, we can see that the months of highest consumption occur during the summer. This finding alerts us that the drought months are also those with the highest consumption. However, a striking finding is that, despite the city having a larger number of households receiving drinking water, this graph shows that the total treated water consumption in the city has been falling every year, as a possible indicator of growing public awareness of the need to save water. Relating this fact (decreased consumption) to the declining water quality of the Sinos (Graph 1), one could question whether companies have been contributing with the same commitment to saving the river.

According to Graphs 4 and 5, both neighborhoods show higher water consumption during the summer and lower consumption during the winter, this being more evident in the Santo Afonso neighborhood. It is noted that in February (in the Santo Afonso neighborhood) there was a drop in water consumption, interrupting the summer peak cycle, probably due to the vacation period for businesses and schools, causing a shift in population demand toward the coast or other regions.

Graph 4 (Santo Afonso Neighborhood) shows a periodic pattern: maximum water consumption in summer and minimum consumption in winter. Water consumption in the first half of 2006 was lower than in the same period in 2007, probably related to the more intense heat that occurred in the summer of 2007. From the first half of 2006 to the first half of 2007, there was a 5% increase in water consumption in the Santo Afonso Neighborhood (again a simple period-over-period comparison, not a formally tested difference — see revision note). This neighborhood consumed 7 times more water than the Operário neighborhood. Since this neighborhood has 7.2 times more connections than the Operário neighborhood, it was to be expected that consumption would be higher. Per capita water consumption is approximately 131 liters per day in this neighborhood (calculated using the Census 2000 population figure for Santo Afonso given in Section 2.4, the only population figure available for this neighborhood in the source data).

In the Operário Neighborhood, on the other hand, the pattern is not as evident, although consumption is also higher in summer and lower in winter. We note that in the first half of 2006, consumption was higher than in 2007, unlike what occurred in the Santo Afonso Neighborhood. It should be taken into account that this neighborhood's smaller population may cause smaller fluctuations in the graph, but even so, they confirm higher consumption in the summer months. Per capita water consumption in this neighborhood is approximately 154 liters per day (likewise using the Census 2000 population figure for Operário given in Section 2.4).

Thus, although the Santo Afonso Neighborhood has more active connections than the Operário Neighborhood, its per capita water consumption is lower than the latter's. Even so, both neighborhoods showed a lower daily per capita consumption than the city average, which is 239 liters per day.

3 CONCLUSION

After evaluating the results, it can be concluded that there is an important interrelationship among rainfall indices, pollution indices, and consumption indices, which fluctuate to form combinations that are sometimes dangerous to the final water quality of the Sinos River, both for the water distributed to the population and for the maintenance of life in the ecosystems related to it.

The water quality situation worsens as monitoring approaches urban areas. In the Luiz Rau Stream (Novo Hamburgo), for example, water quality has worsened over the years of monitoring. The quality of the Sinos River's waters, from the Luiz Rau Stream sub-watershed onward, deteriorates to the point of representing a worrying situation and a potential risk to the environment.

With this type of outlook, future availability may be compromised by pollution stemming from high anthropization. There is a real need to treat these waters, aiming to improve their quality and ensure supply for future generations. However, after analyzing the data, it can also be concluded that total water consumption in the city of Novo Hamburgo has shown a subtle downward trend, whether due to ecological awareness or a reduction in monthly costs. It is also noted that residents of the Santo Afonso neighborhood consume less water than those of the Operário neighborhood, when the results are analyzed per capita.

It is important to emphasize that humanity's relationship with the environment could bring about the most catastrophic predictions regarding the scarcity of natural resources, especially water, making life on Earth unviable within a few years. It is therefore essential to replace this relationship with a vision based on the principles of sustainability, rationalization, and responsibility, within which we are an integral part of the environment and responsible for protecting and improving the quality of life on the Planet.

WATER CHARACTERISTICS IN THE CITY OF NOVO HAMBURGO AND THE NEED OF RATIONAL USE OF WATER RESOURCES

REVISION NOTE (2026)

This section documents the changes applied to this manuscript for the 2026 version. No change below alters the underlying study data, methodology, or conclusions — all changes are corrections to citations, added source attributions, or added methodological caveats.

Changes applied

Added a reference-list entry for INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA, 2006 (Estimativas da população residente...), to resolve the in-text citation to that year, which previously had no matching entry (only the 2000 Census entry existed).
Added a reference-list entry keyed to "SEMAM," used to resolve the Figure 1 map citation — cross-referenced via the existing "MAPA Ambiental..." entry, which names the same publishing body (Secretaria Municipal do Meio Ambiente de São Leopoldo) and year (1998).
Completed the PRÓ-GUAÍBA reference entry with its publication place and year (Porto Alegre, 1998), reattaching the orphaned "Porto Alegre, 1998." line that was printed disconnected from any entry in the original reference list.
Corrected the water-potential figure in the Introduction from "8% of the world's total water potential" to "approximately 12% of the world's surface water resources," per FAO AQUASTAT (added as a new reference entry); the original 8% figure, sourced only to a local newspaper supplement, diverges from the commonly-cited international figure.
Corrected the waterborne-disease mortality figure in the Introduction from "more than ten million people... each year" (unsourced beyond a general link to the UN homepage) to the specific, attributable "1.4 million child deaths per year" figure from the UN World Water Development Report 2 (2006), added as a new reference entry.
Added a methodological caveat to the two period-over-period percentage comparisons in Results (the 6.23% connection increase and the 5% Santo Afonso consumption increase), noting that no formal significance testing was performed.
Added a note specifying that the per-capita consumption figures for both neighborhoods (131 and 154 liters/day) use the Census 2000 population figures given in Section 2.4, the only population figures for these neighborhoods present in the source data.
Replaced the "(MAURITS, 1989)" citation in the opening paragraph of the Introduction — which had no matching reference-list entry and could not be traced to a real source — with United Nations Development Programme, Human Development Report 2006: Beyond Scarcity — Power, Poverty and the Global Water Crisis (Palgrave Macmillan, 2006), per author-supplied correction; added as a new reference entry.
Added the selection rationale for the Santo Afonso / Operário neighborhood comparison to Section 2 (Materials and Methods), per author clarification: Santo Afonso sits immediately upstream of and adjacent to COMUSA's water intake point, while Operário's name and development are tied to Novo Hamburgo's footwear/leather industry and its concentrated industrial activity — contrasting a catchment-area neighborhood against an industrial/effluent-associated one.

REFERENCES

ATLAS Agroclimático do Estado do Rio Grande do Sul. Porto Alegre: Secretaria da Agricultura do Estado do Rio Grande do Sul, 1989.

AVELINE, C.C. et al. Os Banhados do Rio dos Sinos: e por que devem ser preservados. São Leopoldo: Ed. Agatha, 1995.

CLARK, R.M.; COYLE, J.A. Measuring and modeling variations in distributions systems water quality. Journal of the American Water Works Association, v. 82, p. 46-52, 1989.

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