CHAPTER 1

INTRODUCTION

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INTRODUCTION

1.1: GENERAL

Water is absolutely essential to all life, both animal and plant. In order to survive, all animals and plants must have ample supply of water. A water supply which is fit for human consumption is essential to all life.

Water is considered as one of the nutrients, although it yields no calories, yet it enters into structural consumption of cell and is an essential component of diet (Baloch et al. 2000). It constitutes two-third of body cell matter and 90 percent of all body fluids, including the blood as well as lymphatic and spinal fluids. It is necessary for all biological process and also contributes to the regulation of body temperature through perspiration ( Khan, 1999). A daily per capita consumption of two liters of a person weighing 60 kg is generally assumed (WHO,1996).

It is well known that human health and survival depends on use of uncontaminated and clean water for drinking and other domestic purposes. Water has always been one of the most precious commodities. It is source of civilization. Without it, life and civilization could not have survived. Right from the beginning, man has treated water as free gift from God and hence his birthright to use and squander it as he saw fit.

A correct balance in the sensory, physical, chemical and bacteriological quantities of water makes it drinkable (Dartoise and Casamitjana, 1991). In order to be used as healthful fluid for human consumption, water must be free from organisms that are capable of causing diseases and from minerals and organic substances that could produce adverse physiological effects. Drinking water should be aesthetically acceptable, it should be free from apparent turbidity, color, odor, and from any objectionable taste. Drinking water should also have a reasonable temperature. Water meeting this condition is termed as potable, meaning that it may be consumed in any desirable amount without concern for adverse effects on health (AWWA, 1990).

As the whole human population needs drinking water for sustaining life, the provision of a safe water supply is a high priority issue for safeguarding the health and well-beings of humans. The production of adequate and safe drinking water is the most important factor contributing to a decrease in mortality and morbidity in developing countries. The World Health Organization (WHO) reported that nearly half of the population in these countries suffers from health problems associated with lack of drinking water or the presence of microbiologically contaminated water (Van Leeuwen,2000). According to WHO more than 80 percent of human diseases are water borne. In the developing countries 60 percent of population has no access to pure drinking water (Khan et al. 2000).

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There is clear and convincing evidence that the world faces a worsening series of local and regional water quantity and quality problems, largely as a result of poor water allocation, wasteful use of the resource, and lack of adequate management action. Water use has been growing at more than twice the rate of population increase during this century, and already a number of regions are chronically water short. About one third of the world’s population lives in countries that are experiencing moderate to high water stress partly resulting from increasing demands from a growing population and human activities. By the year 2025, as much as two-third of the world population could be under stress conditions (Burks et al; Ahmed, 1999). It is not only quality that has to be preserved and ameliorated but also quantity (Walker and Gordon, 1974).

Provision of regular supply of clean drinking water is a birth right of all the citizens of a country. Contaminated water endangers health and impairs quality of life. Bangladesh is struggling hard to provide its citizens with basic amenities but clean drinking water is not available to great number of people mainly because of rising level of population in the environment, poor upkeep of water supply lines and faulty drainage systems. These result in frequent mixing of human and animal excreta in drinking water, leading to outbreak of water borne diseases (Khan et al. 2000).

Credit for establishing the link between water quality and public health is generally attributed to Dr. John Snow, (1854) whose observation isolated a specific water source as the cause of London’s cholera outbreak in the mid-nineteenth century. However, the link between health and drinking water quality has been broadly recognized for over 4000 years and same is the history of the need to establish standards to ensure its safety.

Water supply sources may be surface waters or ground waters. Surface water is the term used to describe water on the land surface and it is produced by runoff of precipitation and ground water seepage. For regulatory purposes surface water is defined as all water open to the atmosphere and subject to surface runoff. All water beneath the land surface is referred to as under ground or subsurface water. The surface water and ground water resources of an area typically are closely related and are interconnected by the hydrologic cycle. Some ground water sources may be subjected to contamination from surface waters. Source water quality management is the first step in ensuring an adequate supply of safe drinking water. Because surface water and ground water are treated differently under federal regulations, knowing the difference is important (AWWA, 1990).

Many developing regions suffer from either chronic shortage of freshwater or the readily accessible resources are heavily polluted. Accelerated population growth coupled with impoverished socioeconomic development with limited water resources and poor sanitation, leads to an increase in diseases associated with poor living condition among which water related and water borne diseases play a major role (Lehloesa and Muyima, 2000;Kiss et al. 1991). The water is drawn from the boreholes and distributed to the community without any prior treatment.

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Water quality deterioration may occur due to sources of fecal pollution including grazing cattle, natural animal populations, septic tanks, failed sewage systems, recreational users, and summer storm activity etc. (Crabill et al. 1999).

Although the existence and dangers of pathogenic microbes in the surface drinking water supplies have been recognized for more than a century, ground water supplies, and hence wells and springs, were generally long thought to be naturally protected against contamination by pathogenic microbes. This assumes that protection was attributed to the natural filtration and neutralizing properties of sub surfaces soil and geologic strata (Robertson and Edberg, 1997). Contaminants in surface and ground water can range from natural substances leaching from soli, to contaminants introduced by human activities, such as run-off from agriculture activities, discharge from sewage treatment works and industrial plants, and uncontrolled discharges or leakage from landfill sites and from chemical accidences and disasters, reuse dumps, transport accidents, infiltration of polluted rain water, fertilizers etc. Moreover, unsanitary disposal of reuse and garbage, increased of agricultural pesticides and fertilizers, industrial operations, use of pit latrines and problems with septic tank systems, constitute major anthropogenic activities causing groundwater pollution (Baloch et al. 2000;Landon et al. 2000; Sichingabula and Nkhuwa, 1998;Nkhwa, 1998;Knox and Canter, 1996; Koppe, 1973).

Traditionally, microbiological quality of drinking water has been the main concern. Although this concern has not been reduced in recent years, the attention of the general public and health officials on the importance of chemical quality has increased with the increase of our knowledge on the hazard of exposure to chemical substances. It is assumed that there is a potential for all members of the population, including potentially high-risk groups such as young children and health deprived persons to be exposed to drinking water that might contain possible hazardous contaminants. Therefore, strict quality requirement should be set to protect public health (Leeuwen, 2000).

Water is a very good solvent, hence it dissolves some toxic and hazardous substances, producing water pollution problem posing many public health risks through drinking water. There are many physicochemical parameters of interests for water quality assessment. Some of the easily determined ones include temperature, pH, turbidity, hardness. Temperature has a marked influence on the chemical and biochemical reactions that occurs in the water body. High temperature, for instance, increase the toxicity of many substances such as heavy metals and pesticides. It also increases the sensitivity of living organisms to toxic substances (Dojlido and Best, 1993). Hydrogen ion concentration (pH) in water has important influence on living organisms and the surrounding environment of the water. Low pH, for example, accelerates the corrosion of metals as indicated by the corrosion index. The permissible pH range varies between 6.5 and 8.5 for the WHO.

Turbidity in water is caused by the presence of suspended matter, which scatters and absorbs the incoming light. The variety of sources, character and size of suspended solids means that the

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measurement of turbidity gives only an indication of the extent of pollution and is a potential threat for the quality of the drinking water. Furthermore, turbidity concentrations peak during heavy rain episodes (Nebbache et al. 2001). According to WHO the maximum permissible level for turbidity is 5 NTU (Nephalometric Turbidity Unit). Hardness in water is caused by dissolved calcium and to a lesser extent, by magnesium. Acceptable hardness ranges between 100 and 200 mg CaCO3/liter. Hardness of above 200 mg/liter can result in scale deposition particularly on heating. Soft waters with a hardness of less than 100 mg/liter have a low buffering capacity. It has been suggested that intake of very soft waters may have an adverse effect on mineral balance and cause cardiovascular diseases, rectal and esophageal cancer and even mortalities (Sauvant and Pepin, 2000; DWAF, 1996; WHO, 1996; Yang et al. 1999a; Yang et al. 1999b; Dojlido and Best.1993). soft water has a greater tendency to cause corrosion of pipes.

Microorganisms threat to the safety of drinking water is a growing peril even in industrialized nations that have long regarded themselves as immune to wide spread-borne illnesses and carries so common in developing countries (Young, 1996;WHO,1991). Pathogenic bacteria exist at soil surfaces as a result of practices as spreading of liquid manure on agricultural lands or use of treated wastewater for irrigation. Rainfall is a major factor affecting vertical and horizontal movement of bacteria in soil. Surface runoff carries bacteria significant dictances downstream causing serious threats to ground and surface waters. Soil texture plays an important role. E. coli survives in semiarid areas for a long time and increases potential of contamination (Ashour and Hung, 2000).

Routinely, it is impossible to test the water supply for all pathogens including viruses, bacteria, protozoa and helminthes related to water-borne diseases because of the complexity of the testing, the time and cost related to it (Lee and Kim, 2002; Toze, 1999). It is therefore preferable to use indicator systems, which are able to index the presence of pathogens and related healths risks in water for fecal contamination and the possible presence of pathogens in water and waste waters. The presence of pathogens is usually accompanied by the presence of classic indicators of contamination such as Escherichia coli. Enterococci and other aerobic bacteria (Schaffier and Parriaux, 2002). Coliform bacteria have long been used to indicate fecal contamination of water and thus a health hazard (Kratz et al. 1999; Lehloesa et al. 2000).

The quality of drinking water is a complex issue, but is a vital element of health. Poor water quality is reasonable for the deaths of an estimated five million children annually (Holgate, 2000; Thurman et al. 1998). Due to the pressure of increasing population and developing economy all over the world, the present situation of water-quality management is far from sanitary (Hung and Xia,2001).water pollution is becoming a threat, affecting the lives of many people throughout the world, specially living in industrialized areas, because organic and pollution load in natural water countries to increase. In all developed countries, drinking water quality is considered a very serious issue and improvement measures were taken about a century ago. For the evaluation of water pollution, water quality parameters are used for analytical purpose and also provision of safe drinking water to the public. The general public of these countries are aware of water quality

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impacts on human health, hence they are very conscious about it. In developing countries, the mortality rate especially to risk group is very high. This is due to lack of monitoring facilities of water quality as well as improved treatment facilities like treatment plants. Unfortunately public and decision makers of most of the developing world are not well aware of the gravity of the situation.

Although drinking water quality standards may vary from country to country, the objectives remain the prevention of any harmful health impact on the consumers. Due to the scarcity of fresh water, tap water may be erroneously regarded by many rural people to be panacea and concerns regarding its safety as less pressing or even irrelevant. A community should be empowered with alternative means to treat drinking water in order to meet the challenges of providing safe water for every home. Although there are many treatment methods known to date, there is a need to evaluate, redefine and simplify these procedures according to the realities of each community.

Willmitzer (2000) suggests that water protection is always cheaper than expensive water-body restoration and water treatment, therefore, priority is given to the avoidance of contaminants directly at their point of origin. Guideline values ( Annex ….) have been set for the potentially hazardous water constituents and provide a basis for assessing drinking water quality (WHO, 2004).

1.2: AIMS AND OBJECTIVES

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1. To monitor the physic-chemical and bacteriological quality of drinking water of urban populations residing in Dhaka city.

2. To explore and compare all types of drinking water sources of Dhaka city.

3. To explore and compare the quality of surface water at consumer’s end from government sectors of different residential area of Dhaka city.

4. To compare the drinking water supplies of residential and slum area of Dhaka city.

5. To compare all examined water quality parameters with WHO water quality standards and guidelines.

6. To evaluate whether the quality of bottle water supplied in Dhaka city meet their standards.

7. To assess the quality of vended water.

8. To have a health risk assessment of all the water samples collected from different sectors.

9. To give emphasize for the awareness in common people about water quality and its related illnesses.

10. To explore better and safe conditions for better treatment of water.

1.3: LIMITATIONS

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1. In this study only pH, turbidity, color, total hardness, calcium, magnesium, electrical conductivity, arsenic and fecal colifom parameters were analyzed to monitor the physic-chemical and bacteriological quality of drinking water of urban populations residing in Dhaka city. But other parameters like temperature, odor, taste, total dissolved solids, chlorine, nitrate, cobalt, fluoride, iron, lead, nickel parameters would be taken for the analysis of water quality.

2. Only 45 samples were taken in our analysis but analysis would be more reliable if greater number samples were collected.

3. To assess the quality of water in Dhaka city, samples were collected from some selected areas. Number of areas would be increased for better assessment.

4. Water quality parameters may vary from season to season, but this seasonal variation was not shown.

5. For slum water supply calcium and magnesium test were not taken into consideration.

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CHAPTER 2

LITERATURE REVIEW

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2.1 GENERAL

The availability of a water supply adequate in terms of both quantity and quality is essential to human existence. Early people recognized the importance of water from a quantity viewpoint. Civilization developed around water bodies that could support agriculture and transportation as well as provide drinking water. Recognition of the importance of water quality developed more slowly. Early humans could judge quality only through the physical senses of sight, taste, and smell. Not until the biological, chemical, and medical sciences developed were methods available to measure water quality and to determine its effects on human health and well-being.

Concern over the quality of drinking water, and indeed the need to establish standards to ensure its safety, is at least 4000 years old(Raucher,1996). Quality assurance is a set of operating principles that, if strictly followed during sample collection and analysis will produce data of known and defensible quality. That is, the accuracy of the results can be stated with a high level of confidence (APHA, 1995).

Due to the presence of increasing population and developing economy all over the world, the present situation of water quality management is far from satisfactory. To enhance sustainability of water quality management system, in-depth research of the related barriers and the relevant mitigation approach is desired (Hung and Xia, 2001).

Drinking water is either derived from surface water or ground water. The latter is of enormous importance, with more than 65% of Europe’s drinking water needs being supplied in this way. However water from either source is rarely, if ever pure, Industrialization and urbanization together with intensified agricultural activity have led to increased demands for water on the one hand but to the potential for large scale release of contaminants on the other. The results are that surface water can be contaminated through direct or indirect emissions and groundwater can be contaminated from leaching of soil (Holt et al, 2000).

The diversity and number of existing and potential sources of chemical contamination are quite large. It is estimated that there are between 90000 and 10000 chemicals in regular use but than as few as 3000 accounts for about 90% of the total mass used(Holt et al, 2000). More research is needed to assess the relationship between drinking water chemistry and human health (bjorvaln et al, 1997). Funari and outaviani(1997) presented some of he main aspects of the risk to human health associated with the possible exposure, through drinking water, to chemical substances (carcinogenic and non carcinogenic), and biological agents (bacteria, viruses, algae, and macro invertebrates).

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2.2 PH:

PH is a measure of acidic or alkaline condition of water. It is a way of expressing of the hydrogen ion concentration, or more preciously, the hydrogen ion activity. PH is defined as

PH =-log{H+}

Where, {H+} is the concentration (or activity) of hydrogen ion (or proton) in moles per liter (M). Water dissociates to form hydrogen ion (H+) and hydroxyl ion (OH-) according to the following equation:

H2O = H+ + OH-

At equilibrium, we can write,

Kw = {H+} {OH-}/ {H2O}

But since concentration of water is extremely large (approximately 55.5 mol/L) and is diminished very little by the slight degree of ionization, it may be considered as a constant and its activity is taken as 1.0. Thus equation 3 may be written as:

Kw = {H+} {OH-}

Where Kw= equilibrium constant.

For pure water at 25ºC, Kw = 10-7x10-7=10-14. This is known as the ion product of water or ionization constant for water. In other words, water (de-ionized or distilled water) at 25ºC, dissociates to yield 10-7 mol/L of hydrogen ion (H+) and 10-7 mol/L of hydroxyl ion (OH-).

Hence, according to eq. 1, PH of deionized water is equal to 7.

The PH usually represented by a scale ranging from zero to 14, with 7 being neutral. The PH of water greater than 7 is called alkaline and less than is called acidic water. Ground water is often found to be slight acidic due to the presence of excess carbon-di-oxide. Aeration removes carbon dioxide and hence causes a rise in PH value. Some natural waters are sometimes found to be slightly alkaline due to presence of bicarbonate and less often carbonate. Water with PH outside the desirable neutral range may exhibit sour taste and accelerate the corrosion of metallic plumbing fittings and hot water services.

A controlled value of PH is desired in water supplies, sewage treatment and chemical process plants. In water supply PH is important for coagulation, disinfection, softening and corrosion control. In biological treatment of wastewater, PH is an important parameter, since organisms involved in the treatment plants are operative within a certain PH range. According to Bangladesh Environment Conservation Rules (1997), drinking water standard for PH is 6.5-8.5.

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Exposure to low PH can result some effects. Below PH =4 redness and irritation of the eyes have been reported, the severity of which increases with decreasing PH. below PH =2.5, damage to the degree of corrosion of metals as well as disinfection efficiency, it may have an indirect effect on health (WHO, 1996).

2.3 CALCIUM AND MAGNESIUM:

Two vital elements for good health are calcium and magnesium, yet studies show that many Americans do not get the magnesium they need from their diets while nearly half fail to get the needed calcium. Calcium Deficiencies can cause Numerous Problems .Most of us know that calcium is needed for strong bones and teeth, but it is known that the most abundant mineral in the body is also important for helping the heart, nerves, muscles and other body systems work properly. According to the National Institutes of Health, it is not unusual for many individuals to consume less than half the calcium they need for building and maintaining healthy bones. Heavy use of caffeine such as in coffee, large intake of sodium phosphates found in carbonated drinks, and alcohol can decrease the calcium the body retains. Getting enough calcium in the diet is important for preventing a number of health issues. Research has shown calcium may impact conditions such as osteoporosis, hypoarathyroidism, premenstrual syndrome (PMS), high blood pressure, high cholesterol, stroke, colon issues, obesity, tooth and gum disease and insomnia. Calcium is the most plentiful mineral in the body. To function properly, calcium must be accompanied by several other nutrients including Vitamins A, C, D, and K, phosphorus and magnesium. Magnesium - Important for Every Organ in the Body Like calcium, magnesium contributes to the structure of bones and teeth but is also very important for every organ especially the heart, muscles, and kidneys. Perhaps it’s most important jobs are activating enzymes, contributing to energy production and regulating calcium levels along with copper, zinc, potassium, vitamin D and other nutrients. Getting enough magnesium may help conventional treatments for asthma and emphysema, attention deficit hyperactivity disorder (ADHD), diabetes, fibromyalgia, heart disease, high blood pressure, inflammatory bowel disease (IBD), menopause, migraine headaches, osteoporosis, and premenstrual syndrome (PMS).

The possible association between the risk of gastric cancer and the levels of calcium, magnesium, and nitrate in drinking water from municipal supplies was investigated by Yang et al. (1998) in Taiwan. The study also suggested that there was a significant protective effect of calcium intake from drinking water on the risk of gastric cancer. Magnesium also exerts a protective effect against gastric cancer, but only for the group with the highest levels. In Taiwan, two similar investigation revealed by Yang et al.(1999a &1999b) and his team showed significant negative relationship of recial cancer and esopogeal cancer mortalities with drinking water hardness. This was an important finding for the Taiwan water industry and human health. It was reported in a summary of a study in Australia that mortalities from all categories of

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ischemic heart disease and acute myocardial infarction was increased in a community with high levels of soluble solids, calcium, magnesium, sulfate, chloride, fluoride, alkalinity, total hardness, and water when compared with one in which levels were lower (WHO, 1996)

According to Iwami et al. (1994), the incidence of MND (Motor Neuron Disease) in Hehara was well explained by the two parameters, manganese contain in food and the magnesium concentration in drinking water, suggesting that MND in this focus can be understood as a result of excess intake of manganese from food coupled with low intake of magnesium from drinking water.

Calcium & Magnesium, both elements share left / right-sided cell receptors and are essential to human health. Calcium (Ca) and magnesium (Mg) have become the "Gold Standard" when discussing supplements, mineral ratios, paired cell receptors, or many nutrition-related health issues in general. Calcium is now the most promoted nutrient by proponents of conventional, nutritional, and alternative medicine - yet at the same time, the assumed need is based purely on the speculation that the body's calcium intake is well below its requirements. Of the approximately 1,000 g of calcium in the average 70 kg adult body, almost 98% is found in bone, 1% in teeth, and the rest is found in blood, extracellular fluids, and within cells where it is a co-factor for a number of enzymes. Calcium promotes blood clotting by activating the protein fibrin, and along with magnesium helps to regulate the heart beat, muscle tone, muscle contraction and nerve conduction.Parathyroid hormone (PHT) secreted by the parathyroid gland and calcitonin secreted by the thyroid gland maintain serum calcium levels at a range of between 8.5 to 10.5, whereby calcium is mobilized from bone reserves, and intestinal absorption of calcium is increased as needed. The parathormone can also affect renal functions to retain more calcium. When blood calcium rises from too much para-thyroid activity, calcitonin reduces availability of calcium from bone.Chronic calcium deficiency is associated with some forms of hypertension, prostate and colorectal cancer, some types of kidney stones, miscarriage, birth (heart) defects in children when the mother is deficient in calcium during pregnancy, menstrual and pre-menstrual problems, various bone, joint and periodontal diseases, sleep disturbances, mental health / depressive disorders, cardiovascular and/or hemorrhagic diseases, and others. Elevated calcium levels are associated with arthritic / joint and vascular degeneration, calcification of soft tissue, hypertension and stroke, an increase in VLDL triglycerides, gastrointestinal disturbances, mood and depressive disorders, chronic fatigue, increased alkalinity, and general mineral imbalances. High calcium levels interfere with Vitamin D and subsequently inhibit the vitamin's cancer-protective effect unless extra amounts of Vitamin D are supplemented.There are about 19 g of Magnesium in the average 70 kg adult body, of which approximately 65% is found in bone and teeth, and the rest is distributed between the blood, body fluids, organs and other tissue. Magnesium is involved in the synthesis of protein, and it is an important co-factor in more than 300 enzymatic reactions in the human body, many of which contribute to the production of energy, and with cardiovascular functions. While calcium affects muscle contractions, magnesium balances that effect and relaxes muscles. Most of magnesium is inside the cell, and while iron is the central atom in hemoglobin, magnesium is the central core of the chlorophyll molecule in plant tissue.Although the process of absorption for magnesium is similar to that of calcium, some people absorb or retain much more magnesium than calcium (or more calcium than magnesium), so the

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commonly suggested supplemental intake ratio of 2:1 for calcium and magnesium is really an arbitrary value that can change significantly under various individual circumstances.Low levels of magnesium can be a causative, contributing, or aggravating factor with kidney stones (usual recommendations for prevention are 400mg of magnesium oxide and 50mg of Vitamin B6 daily), high blood pressure, mitral valve prolapse (MVP), arrhythmia, tachycardia, coronary artery spasm and other types of heart problems, premenstrual syndrome (PMS) or menstrual cramps, tetany (sustained contractions, convulsions), (pre)eclampsia - particularly when too much iron and not enough folic acid was taken during pregnancy, insomnia, anxieties, chronic constipation, hyperactivity - particularly with children, and others (see bottom of page). However, frequent and excessive use of magnesium sulfate (Epsom salt) or antacid remedies such as Milk of Magnesia can eventually trigger a number of medical problems resulting from other minerals such as calcium, sodium, iron, or potassium getting out of balance. This is more prevalent with kidney diseases and may include severe fatigue, depression, low blood pressure, gastrointestinal problems, dizziness, dehydration / dry skin, diarrhea, muscular / joint problems and cardiovascular diseases.An interesting aspect about these trace minerals is the similarity of medical conditions that result from both, excessive, or deficient levels. For instance, low calcium or copper levels increase the risk for vascular (cerebral) hemorrhage, while high levels promote vascular degeneration (arteriosclerosis).With arthritis, low calcium or copper levels cause inflammatory types of joint disease, while high levels cause degenerative (osteo-arthritic) joint damage.Depression can be related to high and low levels of calcium and/or magnesium also, with low levels being often times associated with anxieties as well. After comparing the backgrounds of patients who required very high doses (4,000+mg) of calcium a day - just to barely reach normal levels, it turned out that a very large percentage had a history of benzodiazepine (tranquilizers / sedatives) use. These drugs either affected their body's ability to utilize calcium and/or magnesium properly, or those minerals levels in these patients had already been extremely deficient before taking any medications, provoking insomnia, anxieties, or other symptoms, and resulting in drugs (benzodiazepines) being prescribed instead of having the real cause (mineral deficiencies) corrected. Unfortunately, this type of symptomatic drug therapy continues to be a trademark of modern medicine.

2.4 COLOR:Pure water is colorless, but water in nature is often colored by foreign substances. Water whose color is partly due to suspended matter is said to have apparent color. Color contributed by dissolved solids that remain after removal of suspended matter is known as true color.

After contact with organic debris such as leaves, conifer needles, weeds, or wood, water picks up tannins, humic acid, and humates and takes on yellowish-brown hues. Iron oxides cause reddish water, and manganese oxides cause brown or blackish water. Industrial wastes from textile and dyeing operations, pulp and paper production, food processing, chemical production, and mining, refining, and slaughter house operations may add substantial coloration to water in receiving streams.

Colored water is not aesthetically acceptable to the general public. In fact, given a choice, consumers tend to choose clear, noncolored water of otherwise poorer quality over treated

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potable water supplies with an objectionable color. Highly colored water is unsuitable for laundering, dyeing, paper making, beverage manufacturing, dairy production and other food processing, and textile plastic production. Thus, color of water affects its marketability for both domestic and industrial use.

While true color is not usually considered unsanitary or unsafe, the organic compounds causing true color may exert a chlorine demand and thereby seriously reduced the effectiveness of chlorine as a disinfectant. Perhaps more important are the products formed by combination of chlorine with some color producing organics. Phenolic compounds, common constituents of vegetative decay products, produce very objectionable taste and odor compounds with chlorine. Additionally, some compounds of naturally occurring organic acids and chlorine are either known to be, or are suspected of being, carcinogens (cancer causing agents).

Color in natural waters is due mainly to organic matter, which originate from soil, peat, and decaying vegetation. In addition, inorganic iron and manganese are present in some ground waters and surface waters and may impart a red and black hue, respectively. Discoloration of potable water may arise from the dissolution of iron (red) or copper (blue) in distribution pipes, which can be enhanced by bacteriological processes. Microbiological action may also produce “red water” resulting from the oxidation of iron (II) to iron (III) by “iron bacteria”. Similarly, black discoloration may result from the action of bacteria capable of oxidizing dissolved manganese to give insoluble forms. Furthermore, color producing organic substance can react with chlorine to produce undesirable levels of chlorination by-products (WHO 1996).

Color is not a parameter usually in waste water analysis. In potable water analysis, the common practice is to measure only the true color produced by organic acid resulting from decaying vegetation in the water. The resulting value can be taken as an indirect measurement of humic substances in the water.

2.5 TURBIDITY:

A direct measurement of suspended solids is not usually performed on the samples from natural bodies of water or on potable (drinkable) water supplies. The nature of the solids in these waters and the secondary effects they produce are more important than the actual quality. For such waters a test for turbidity is commonly used.

Turbidity is a measure of the extent to which light is either is either absorbed or scattered by suspended materials in water. Because absorption and scattering are influenced by both size and surface characteristics of the suspended material, turbidity is not a direct quantitative measurement of suspended solids. For example, one small pebble in a glass of water would produce virtually no turbidity. If these pebbles were crushed into thousands of particles of colloidal size, a measurable turbidity would result, even though the mass of solids had not changed.

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Most turbidity in surface water results erosion of colloidal material such as clay, silt, rock fragments, and metal oxides from the soil. Vegetable fibers and microorganisms may also contribute to turbidity. Household and industrial wastewaters may contain a wide variety of turbidity producing material. Soaps, detergents, and emulsifying agents produce stable colloids that result in turbidity. Although turbidity measurements are not commonly run on wastewater, discharge of wastewaters may increase the turbidity of natural bodies of water.

When turbid water in a small, transparent container, such as a drinking glass, is held up to the light, an aesthetically displeasing opaqueness or “milky” coloration is apparent. The colloidal material is associated with turbidity produces adsorption sites for chemicals that may be harmful or cause undesirable taste and odors and for biological organisms that may be harmful. Disinfection of turbid waters is difficult because of the adsorptive characteristics of some colloids and because the solids may partially shield organisms from he disinfectants.

In natural water bodies, turbidity may impart a brown or other color of water, depending on the light absorbing properties of solids, and may interfere with light penetration and photosynthetic reactions in streams and lakes. Accumulation of turbidity-causing particles in porous streambeds results in sediment deposits that can adversely affect the flora and fauna of the stream.

Turbidity measurements are normally made on clean waters as opposed to wastewaters. Natural waters may have turbidities ranging from a few NTU to several hundred.

In 1999, Power and Navy determined the relationship between bacterial regrowth and some physical and chemical parameters within Sydney’s drinking water distribution system. Their results showed that regrowth was present within the system and the certain parameters, such as turbidity and distance from the initial treatment point, correlated with the presence of high bacterial numbers. Turbidity has been shown to be correlated with contamination with Glardia and Cryptosporidium and serves as a surrogate measure for risk of contamination by these pathogens. Morris et al. (1996) compared daily counts of diagnosed gastroenteritis (gastrointestinal events) in Milwaukee County. Wisconsin, from January 1992 through April 1993 with reported daily turbidity from the two drinking water treatment plants. Turbidity in both plants was associated with an increased number of gastrointestinal events even after exclusion of a major documented outbreak of Cryptosporidiosis. During the 434 day period prior to the outbreak, an increase in turbidity of .5 NTU at one of the plants was associated with relative risks for gastrointestinal events of 2.35 among children.

2.6 ELECTRICAL CONDUCTIVITY:

As in the case of metallic conductors, electrical current can flow through a solution of an electrolyte also. For metallic conductors: current is carried by electrons, chemical properties of metal are not changed and an increase in temperature increases resistance. The characteristics of current flow in electrolytes in these respects are different. The current is carried by ions,chemical changes occur in the solution and an increase in temperature decreases the resistance.

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Electrical conductivity (EC) is a measure of the ability of water to conduct an electric current and depends on concentration of the ions (higher concentration, higher EC), Temperature of the solution (high temperature, higher EC), Specific nature of the ions (higher specific ability and higher valence, higher EC).

Pure water strongly resists the passage of an electric current. However, when salts are dissolved in water they improve its conductivity, so the greater the quantity of dissolved salts water contains the higher will be its conductivity reading. A measure of electrical conductivity is therefore commonly used as a fairly reliable indicator of the degree of salinity of a water samples. It does not identify the specific dissolved salts, or the effects on crops or solis. The electrical conductivity reading of a solution is temperature dependent, and EC thresholds are usually based on a temperature 25ºC.

Conductivity changes with storage time and temperature. The measurement shouldtherefore be made in situ (dipping the electrode in the stream or well water) or in the field directly after sampling. The determination of the electrical conductivity is a rapid and convenient means of estimating the concentration of ions in solution. Since each ion has its own specific ability to conduct current, EC is only an estimate of the total ion concentration.In the international system of units (SI) the electrical conductivity is expressed in Siemens which is the reciprocal of resistance in ohm. The older unit for conductance was mho. Report conductivity as milli Siemens per meter at 25ºC (mS.m-1).

Conductivity is highly temperature dependent. Electrolyte conductivity increases with temperature at a rate of 0.0191 mS/mºC for a standard KCI solution of 0.0100 m. For natural waters, this temperature coefficient is only approximately the same as that of the standard KCI solution. Thus, the more the sample temperature deviates from 25°C the greater the uncertainty in applying the temperature correction. Always record the temperature of a sample (+0.1ºC) and report the measured conductivity at 25ºC (using a temperature coefficient of 0.0191 mS/mºC)

Most of the modern conductivity meters have a facility to calculate the specific conductivity at 25ºC using a built in temperature compensation from 0 to 60ºC. The compensation can be manual (measure temperature separately and adjust meter to this) or automatic (there is a temperature electrode connected to the meter).

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Current is carried by both cations and anions, but to a different degree. The conductivity due to divalent cations is more than that of mono-valent cations. However, it is not true for anions. The conductivity factors for major ions present in water are listed below.

Table 2.1: Conductivity Factors for ions commonly found in water

Ion Conductivity Factor µS/cm per mg/L

Cations Ca 2+ 2.60 Mg2+ 3.82 K+ 1.84 Na+ 2.13 Anions HC03 0.715 CI 2.14 SO4 2- 1.54 N03 1.15

The conductivity of a water sample can be approximated using the following relationship EC =

S (C, X f,)

in which EC = electrical conductivity, µS/ cm Ci = concentration of ionic specie i in solution, mg / L fi = conductivity factor for ionic specie i

2.7 ARSENIC:

Arsenic, the 20th most abundant element in earth’s crust and 12tha most abundant element in biosphere, is a common trace inorganic contaminant in drinking water and is identified as a significant health risk. Arsenic is known for its high toxicity and its ability to induce cancer after long term ingestion. Presence of elevated levels of arsenic in ground water (especially from shallow aquifer) has become a major concern in Bangladesh. Arsenic pollution oh ground water is challenging in Bangladesh since tube well water extracted from shallow aquifers is a major source drinking water for most of its population. The rural water supply is most entirely based on groundwater supply through use of hand pump tube wells; the most urban water supply is also heavily dependent on groundwater.

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Awareness about the presence of arsenic in ground water has been growing since late 1993 when arsenic was first detected in the district of Chapai Nawabgonj the West-Bengal district of India. Since then higher levels of arsenic (exceeding the WHO standard of .01 mg/L and Bangladesh standard of .05 mg/L) have been detected in many regions of the country. Affected areas and estimates of affected population are being updated, as more data are becoming available. Out of 64 administrative districts of Bangladesh, arsenic contamination has so far been reported in 61 districts and an estimated 20 million people are at risk of arsenic toxicity. This has lowered the population coverage of safe water supply to an estimated 80 percent from an impressive figure of nearly 98 percent. The southern and northeastern districts are the worst affected.

In Bangladesh, the arsenic in ground water is of geologic origin and is probably only apparent now because it is only the last 20-30 years that ground water has been extensively used for drinking in rural areas. Weathering of arsenic-rich base metal sulfides in the upstream of Ganges basin appears to be a major source of arsenic-rich iron oxyhydroxides in the sediments of Bangladesh. Arsenic-rich iron oxyhydroxides appear to be the major source of arsenic, from which arsenic is released as a result of dissolution and desorption. Reducing environment in the alluvial aquifer, primarily due to the presence of organic mater, promotes dissolution of iron oxyhydroxides and released of arsenic. Use of phosphet fertilizer can potentially enhance release of arsenic as a result of replacement of arsenic by phosphet ions on the absorption sites of iron oxyhydroxides. Natural and anthropogenic procuresses that may lead to release mobilization of arsenic in the subsurface are being investigated.

According to ECR 1997, drinking water for arsenic in Bangladesh is 50 ppb (or 50 ppm). The WHO guideline value for arsenic in drinking water is 10 ppb and the USEPA is also planning to revise its standard from 50 ppb to 10 ppb.

Arsenic occurs in water in several different forms, depending upon the PH and the redox potential Eh. in groundwater, arsenic primarily exists as inorganic arsenic. Inorganic trivalent arsenic, [As(III)] or arsenite is the dominant form in reducing environment, while inorganic pentavalent arsenic [(As(V)] or arsenate is the dominant form in oxidizing or aerobic environment. In groundwater environment where the conditions are mostly reducing, a significant part of the arsenic exists as [As(III)]. In the PH range of most groundwater (i.e. PH 6-9), dominant chemical form of As(III) is H3AsO3, while dominant chemical forms of As(V) in the PH range are H2AsO4

-, HAsO4

-.

2.8 FECAL COLIFORM:

A variety of different microorganisms are found in untreated water. Most of these organisms do not pose a health hazard to humans. Certain organisms referred to as pathogens, cause disease to humans which include species of bacteria, viruses and protozoa. These organisms are not native

19

to aquatic systems and usually require an animal host for growth and reproduction. They can, however be transported by natural water systems, thus becoming a temporary member of the aquatic community. Many species of pathogens are able to survive in water and maintain their infectious capabilities for significant periods of time. From the prospective of human and consumption, the most important organisms in water are the pathogens.

One might assume that a water sample is analyzed to search for pathogenic organisms. This is not true, however for the following reasons:

Pathogens are likely to gain entrance sporadically, and they do not survive for very long period of time, consequently they could be missed in a sample submitted to the laboratory.

If they are present in a very small numbers, pathogens are likely to escape detection by laboratory procedures.

Although it is possible to detect the presence of various pathogens in water, the isolation and identification of many of these is often extremely complicated and seldom quantitative.

Analysis of water for all known pathogens would be a very time-consuming and expensive proposition.Tests for specific pathogens are usually made only when there is a reason to suspect that those particular organisms are present. At other times, the microbiological quality of water is checked using indicator organisms. An indicator organism is one whose presence presumes that contamination has occurred and suggests the nature and extent of the contaminants. It is known that most pathogens that are likely to be transmitted via the water route are shed in human and or animal feces. Hence, an indicator organism should be a microorganism whose presence is evidence of fecal contamination of warm blooded animals. Indicators may be accompanied by pathogens, but typically do not cause disease themselves. The ideal indicator organism should have the following characteristics:

Be applicable to all waters Always be present when pathogens are present Always are absent when pathogens are absent Numbers should correlate the degree of pollution Be present in greater number than pathogens There should be no after-growth or re-growth in water There should be greater or equal survival time than pathogens Be easily and quickly detected by simple laboratory tests Should have constant biochemical and identifying characteristics Harmless to humans.

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No organisms or group of organisms meet all of these criteria, but the coliform bacteria fulfill most of them, and this group is most common indicator in use today. Each person discharges about 100 to 400 billion coliforms each day. Thus, the presence of colifom organisms is taken as an indication that the water is free from pathogens. Total coliforms are defined as gram negative bacteria which ferment lactose at 35ºC or 37ºC, with the production of acid, gas and aldehyde within 24 to 48 hours. They are cytochrome oxidase negative and are non spore forming.Total Coliform(TC)=Fecal Coliform(FC)+Non-fecal coliform

Fecal coliforms(thermo-tolerant coliform) are a subgroup of total coliforms, which live in the warm blooded animals and have the same properties as the total coliforms but tolerate and grow at the higher selective temperature range of 44ºC to 44.5ºC. In addition, they form indole from tryptophan and these combined properties, when positive, are regarded as presumptive Escherichia Coli(presumptive E.coli).

The coliform group includes several genera, which may all be of fecal origin. Under suitable conditions these can multiple in the presence of contamination by organic material. Some coliform species are frequently associated with plant debris or may be common inhabitants in soil or surface waters which are called non-fecal coliforms. Thus, the total colifom group should not be regarded as an indicator of organisms exclusively of fecal origin, especially in very hot countries where coliforms of non fecal origins are usually present. The use of total colifoms as an indicator may therefore be of little value in assessing the fecal contamination of surface water, especially the water of unprotected shallow wells where contamination by coliforms of non fecal origin can occur. However, it may be of value deep-well water although even this water may occasionally become contaminated with coliform of non-fecal origin. The measurement of total coliforms is of particular relevance for treated and/or chlorinated water supplies, in this case the absence of total coliforms would normally indicate that the water has been sufficiently treated/disinfected to destroy various pathogens. Measurement of fecal coliforms is a better indicator of general contamination by material of fecal origin. The predominant species is Escherichia coli (E.coli), which is exclusively of fecal origin.

Le Chevallier et al. (1996) found that the occurrence of coliform bacteria was significantly higher when water temperatures were >15ºC. According to Sisti et al. (1998) the effect of the chlorine compound is markedly influenced by water temperature.

2.9 HARDNESS:

Hardness is defined as the concentration of multivalent metallic cations in solution. At supersaturated conditions, the hardness cations will react with anions in the water to form a solid precipitate. Hardness is classified as carbonate hardness and non carbonate hardness, depending

21

upon the anion with which it associates. The hardness that is equivalent to the alkalinity is termed carbonate hardness, with any remaining hardness being called noncarbonated hardness.

Carbonate hardness is sensitive to heat and precipitates readily at high temperatures.

Ca(HCO3)2 = CaCO3 + CO2 +H2O

Mg(HCO3)2 = Mg(OH)2 +2 CO2

The multivalent metallic ions most abundant in natural waters are calcium and magnesium. Others may include iron and manganese in their reduced states (Fe2+, Mn2+), strontium (Sr2+ ), and aluminium AL3+). They are usually found in smaller quantities than calcium and magnesium, and for all practical purposes, hardness may be represented by the sum of calcium and magnesium ions.

Soap consumption by hard waters represent to the economic loss of the water user. Sodium soap react with multivalent metallic cations to form a precipitate, thereby losing their surfactant properties. A typical divalent cation reaction is:

2NaCO2C17H33 + cation2+ = cation2+ (CO2C17H33)2 + 2Na+

Lathering does not occur until all of hardness ions are precipitated, at which point the water has been “softened” by the soap. The precipitate formed by hardness and soaps adheres to surfaces of tubes, sinks, and dish washers and may stain clothing, dishes, and other items. Residues of the hardness soap precipitate may remain in the pores, so that skin may feel rough and uncomfortable. In recent years these problems have been largely alleviated by the development of soaps and detergents that do not react with hardness.

Boiler scale, the result of carbonate hardness precipitate may cause considerable economic loss through fouling of water heaters and hot water pipes. Changes in ph in the water distribution systems may also results in deposits of precipitates. Bicarbonates begin to convert to the less soluble carbonates at PH values above 9.0.

Magnesium hardness, particularly associated with the sulfate ion, has a laxative effect on persons unaccustomed to it. Magnesium concentration at less than 50 ppm is desirable in potable waters, although many public water supplies exceed this amount. Calcium hardness presents no public health problem. In fact, hard water is apparently beneficial to the human cardiovascular system.

Analysis for hardness is commonly made on natural waters and on waters intended for potable supplies and for certain industrial uses. Hardness may range from practically zero to several hundred, or even several thousands, parts per million. Although acceptability levels vary according to a consumer’s acclimation to hardness, a generally accepted classification is as follows:

Soft < 50 ppm as CaO3

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Moderately hard 50-150 ppm as CaO3

Hard 150-300 ppm as CaO3

Very hard >300 ppm as CaO3

The public health service standards recommend of 500 ppm of hardness in drinking water.

Boulay and Edwards (2001) reported the role of temperature and chlorine in copper corrosion by-product released in soft water. Soft, low alkalinity drinking waters tend to cause relatively high copper corrosion by-product release in plumbing systems. Long term tests (6-8 months) confirmed that lower PH and higher temperature increased release of copper in water.

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CHAPTER 3

DESCRIPTION OF SITE AND SAMPLING PLAN

24

3. DESCRIPTION OF SITE AND SAMPLE PLAN

3.1 LOCATION

Dhaka Capital City lies between 23.79º C north latitude and 90.30 º C east longitudes. The Dhaka city is spread over an area of 1463 sq. km. The site is even table and land is in an elevation between 2 and 13 meters above sea levels. Within Dhaka city, samples were collected from Mohammadpur residential area(area-1), Dhanmondi residential area (area-2), Buet residential halls, Geneva camp (slum-1), Lalbagh slum (slum-2). Bottled mineral waters and vending waters were also included in our samples.

3.2 GEOLOGY:

Dhaka, the capital city of Bangladesh, is located mostly on Holocene river deposits at the southern fringe of the Madhupur Tract, a Pleistocene inlier. Vertical Electrical Sounding provides a snapshot of sediment distribution in Dhaka down to a depth of 241 m. Clay is dominant in the central and northern part of the city, whereas sand sequences outweigh the southwestern part. Sand percentages increase with depth toward northeast.

3.3 CLIMATE:

Dhaka city has distinct seasons marked by wide variation in temperature with the minimum and maximum (for coldest and hottest months) of 13ºC and 36ºC (1999). The area has a rainfall season called monsoon season which lasts from May to October. Average rainfall of Dhaka city is 1931 mm.

3.4 DRAINAGE:

The Dhaka City is bounded by four rivers: Balu on the east; Tongi Khal on the north; Turag on the west; and Turag-Buriganga on the south. The drainage of the City areas is mostly depended on the water levels of the peripheral rivers. The major drainage channels (locally known as Khal) in the City are Dholai khal, Gerani khal, Segunbagicha khal and Begunbari khal, which collects catchment runoff and drains to the peripheral rivers.

The drainage network of the Dhaka City is very complex. The Segunbagicha khal, the main drainage channel of the area carries catchment runoff to the Balu river. The khal after originating from a park travels a distance of 3.4 km to cross a road through a sluice gate and then meets with another drainage khal before draining finally into the Balu river. The khal covers a drainage area

of 4.54 km2

upto the sluice gate. The Segunbagicha khal was originally a natural channel. A rectangular-shaped concrete conduit has replaced a portion of it (first 2.1 km).

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FIGURE 3.1: MAP OF DHAKA CITY

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3.5 TYPES OF SUPPLY IN DHAKA CITY:

Presently DWASA can meet only 60 percent of the demand of its service area population. The gap between demand and supply is also rapidly increasing. In Dhaka the water supply is ground water based and 82 percent of the supply is abstracted from the underground aquifers. The rest 18 percent is derived from surfaces water sources. Available data indicate that due to overexploitation ground water table is falling rapidly and ground water is being mined significantly. This has not only made water supply system unsustainable but the city has been exposed to environmental hazards.

3.6 SAMPLING PLAN:

To get an overall idea about the water quality of Dhaka city the water samples were collected from several sectors. Two residential areas, two slum areas along with bottle water supply and vended water supply was investigated. The water samples were analyzed for physical, chemical and bacteriologycal quality. In all tests, findings were correlated with human health. For the whole study 45 samples were collected from different areas of Dhaka city. Details are given below:

Table 3.1: Sampling plan for water analysis of Dhaka city

Designation Site Sample No.

Type of analysis

Residential area -1

Resident Mohammadpur 1-5 Physical,Chemical and biological

BUET hall Buet Hall Polashi 6-10 Physical,Chemical and biologicalSlum area -1

Slum Mohammadpur 11-15 Physical,Chemical and biological

Bottle mineral water

Bottle New market,Nilkhet 16-25 Physical,Chemical and biological

Vending water

Vending 26-35 Physical,Chemical and biological

Slum area -2

Slum Lalbagh 36-40 Physical,Chemical and biological

Residential area -2

Resident Dhanmondi 41-45 Physical,Chemical and biological

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FIGURE 3.2: REPRESENTATIVE MAP OF LOCATION OF SAMPLES FROM BABAR ROAD

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FIGURE 3.3: REPERSENTATIVE MAP OF LOCATION OF SAMPLES FROM BUET

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FIGURE 3.4: REPRESENTATIVE MAP OF LOCATION OF SAMPLES FROM SLUM AREA 1

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FIGURE 3.5: REPRESENTATIVE MAP OF LOCATION OF SAMPLES FROM SLUM AREA-2

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FIGURE 3.6: REPRENTATIVE MAP OF LOCATION OF SAMPLES FROM DHANMONDI (AREA-2)

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3.7 SAMPLING OF WATER SAMPLES:

Water samples were collected from different areas of Dhaka city. Then these water samples were brought to laboratory for physical, chemical and bacteriological investigations.

Other information about water distributed to the cities of Dhaka was gathered from concerned authorities. With the help of maps of Dhaka city, sites of sampling were selected and planned, so that all types of waters were sampled covering all areas of Dhaka city like only surface waters. Samples were collected from these planned sites for their physical, chemical and bacteriological analysis.

FIGURE 3.7: BOTTLE MINERAL WATER AND VENDING WATER SAMPLES

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CHAPTER 4

MATERIALS AND METHODOLOGY

4.1: SAMPLING AND PRESERVATION:

34

All the sampling and preservation procedures for water samples were performed according to the standard methods for the examination of water according to the guidelines of drinking water quality (WHO, 2004).

For physicochemical analysis bottles were washed with sampling water for three times. Plastic Poly ethylene (PET) bottles were used, cleaned and rinsed carefully.

Sampling for bacteriological analysis was done especially with care, ensuring that there is no external contamination of the samples. During sample collection, ample air space was left in the bottle (at least 2.5 cm) to facilitate mixing by shaking, before examination. Sample bottles were kept close until filled (without rinsing) and caps were replaced immediately. In case of tap water samples, tap was opened fully, and water was let to run to waste for 2 or 3 minutes, and reduced water flow to permit filling bottle without splashing.

Proper sampling plan was set to provide adequate representation to the samples according to the title of the study.

4.2: ANALYSIS OF PHYSICAL PARAMETERS

Table 4.1 is showing the out lines of methodology involved in the measurement of the physical properties of the samples. Many of the determinations included here such as color, electrical conductivity, hardness and turbidity fit this category unequivocally. However physical properties cannot be divorced entirely from chemical composition.

Table 4.1: Methods of physical analysis along with there apparatus.

4.3: DESCRIPTION OF THE METHODS

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Element Method ApparatuspH Electrometric

methodpH meter

Colour spectrophotometer HACH ,DR 4000U

Electrical conductivity

HACH conductivity

HACH conductivity Meter

Total hardness EDTA titrametric method

HACH Auto titration device

Turbidity Standard nephelometry procedure

DR LANGE turbidity Meter

4.3.1 pH

1. Calibration of the pH meter was performed using standard pH solutions. The calibration procedure would depend on the pH range of interest.

2.100 ml of the sample was taken in a beaker. It was made sure that the sample was not agitated in order to avoid exchange of gases between sample and atmosphere.

3. pH meter was inserted in the sample. Some time was given for attainment of equilibrium. pH meter was turned on and the reading was taken.

4.3.2: COLOR

1. Spectrophotometer was adjusted for programmed no. 120 and wavelength 455 nm.

2. The sample cell was filled with distilled water, cell was inserted into the instrument and zero was set.

3. Then sample water was filled in the cell and READ button was pressed. The reading was taken.

4.3.3: ELECTRICAL CONDUCTIVITY

1. Conductivity meter was cleaned. 100 ml sample was taken in a beaker.

2. Conductivity meter was inserted into the sample, it was turned on and time was given to achieve equilibrium.

3. Reading was taken.

4.3.4: TOTAL HARDNESS

1.50 ml sample was taken in a 150 ml beaker.

2. 1 ml of standard buffer solution (supplied by HACH) was added to raise the pH of water sample to about 10.

3. One packet of Eriochrome Black T dye (supplied by HACH) indicator was added to the beaker.

4. The cartridge containing standard EDTA solution was fitted to the titration device (supplied by HACH).

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5. The flow control knob of the device was turned on until the solution starts to come out of the tube fitted to the cartridge. The initial reading of the counter was taken.

6. Tube fitted to the cartridge was inserted into the water sample and titration was started (under constant stirring) by turning the flow control knob of the auto titrator. It was continued until the wine red color of the sample turned into blue. The final reading of the counter was taken.

4.3.5: TURBIDITY

1. It was ensured that the turbidity meter had been standardized recently.

2. The clean sample cell was filled with water sample and it was placed in the sample cell holder. The sample cell was covered with the light shield. The switch was turned on and reading was taken of turbidity directly from the monitor.

4.4: CHEMICAL EXAMINATIONS

For determination of the concentration of the chemical constituents like calcium, magnesium, arsenic atomic absorption spectrophotometric method was used.

4.5: BACTERIOLOGICAL ANALYSIS

Bacteriological analysis was done using the membrane filter (MF) method. This method gives a direct count of the fecal coliform present in a given sample of water. This method is based on filtration of a known volume of water through a membrane filter consisting of a cellulose compound with a uniform pore diameter of 0.45 µm. The bacteria are retained on the surface of the membrane filter. When the membrane containing the bacteria is incubated in a sterile container at an appropriate temperature with a selective differential culture medium, characteristics colonies of fecal coliforms developed, which can be counted directly. This technique is popular with the environmental engineers.

Colonies of fecal coliform bacteria are blue in color. This color may cover the entire colony or appear only in the centre of the colony.

Determination of no of colonies as followed.

1. The Erlenmeyer flask (side arm) was connected to the vacuum source (turned off) and the porous support was placed in position.

2. A petridish was opened and a pad was placed in it.3. With a sterile pipette 2 ml of selective broth medium was added to saturate the pad.4. The filtration unit was assembled by placing sterile membrane filter on the porous

support, using forceps sterilized earlier by flaming.

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5. The upper container was placed in position and it was secured with the special clamps.6. 100ml sample was poured in the upper container.7. After the sample was passed through the filter the vacuum was disconnected and the

container was rinsed with 20-30 ml sterile dilution water.8. The filtration unit was taken apart and using the forceps, the membrane filter was placed

in the petridish on the pad with the grid side up. It was made sure that no air bubble was trapped between the pad and the filter.

9. The petridish was inverted for incubation.10. The dish was placed in an incubator at 44±0.5 ºC for 24 hours at 100% humidity.

The numbers of fecal coliform colonies were counted by,

Fecal coliform per 100 ml = ( no of coliform colonies counted) x(100)/(ml of sample filtered )

4.6 STATISTICAL ANALYSIS

Total 45 samples of different consumer category were analyzed physically, chemically and bacteriologycally. The mean value of all the parameters for all the categories were determined and diagramically represented as bar charts, so as to compare the samples with the standard value.

For the parameters were guideline values are given, the statistical analysis are not applied generally. However, along with the mean value confidence intervals (95%) were also calculated for each case. By adding and subtracting confidence interval (CI) from its mean, range of possible variation in mean can be worked out if the number of samples is more which is correct up to 95%. This (confidence interval) helps to determine the range in which the 95% of the readings lie (mean ± confidence interval). It was also observed whether WHO guideline values was above or below the range ( table VIII )

To observe the overall quality , samples of residential area 1 and slum area1 was compared by Student´s t- test as described by Steel and Torric(1960).p<.05 was considered the minimum value for statistical significance. Using the same test comparison between bottle mineral water and vending water was also done.

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CHAPTER 5

ANALYSIS OF RESULTS

5.1.1: Results of different parameters

39

Study of drinking water quality at the point of consumption was done on the basis of different category. Water consumption by people in residential area, slum area, residential halls and also commercial water supply by different mineral water industry and vended water samples were tested separately. The samples were properly analyzed for physical, chemical and bacteriological quality.

Out of these 45 samples, 22.22% were from residential, 22.22% were from slum, 44.44% from commercial from commercial, 11.11% from residential hall of BUET. 88.89% samples were from govt. supply and 11.11% were from water supply by BUET.

Water samples were taken to Environmental laboratory of BUET for their physical, chemical and bacteriological analysis. Some important tests of immediate nature were performed immediately after they were taken to laboratory.

This chapter represents the results of bacteriological plus physico-chemical analysis of water consumed by people of Dhaka city under different categories.

5.1.2: Bacteriological examination

Results of microbial examination of the samples collected showed that most of these water samples were positive for fecal coliforms. 60% of the total samples were found contaminated by coliform bacteria. Residential area 1 and 2 are 100% positive for F.C where as the samples of slum areas were found TNTC (too numerous too count). Residential halls of Buet and Bottle mineral water were free from microbial contamination but the vended water samples were found contaminated which had bacterial growth as high as 200 per 100 ml.

5.1.3: PHYSICAL AND CHEMICAL ANALYSIS

In this study out of 45 samples of Dhaka city except water samples from hall, all of them were from government sector. These water samples were analyzed for different parameters according to their respective analytical techniques and the results are presented as under:

5.1.4: PHYSICO-CHEMICAL ANALYSIS AT SITE

PH :

The PH values of all the water samples ranged from 6.54 to 7.37 and the mean value was 6.95, in case of Residential the range was 6.82 to 7.28 with mean value of 7.05

In slum area the range was 6.6 to 6.9 with mean value of 6.75. For bottle water range was 6.6 to 7.3 and mean was 7.036. For vending water range was 6.86 to 7.37 with the mean of 7.0956.

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COLOR:

Almost all the samples of bottle mineral water were colorless except two which were Spa and Fine. Among all the samples, samples collected from both the slum areas were found to have higher value than others, although all the samples were below the WHO guideline values for color.

ELECTRICAL CONDUCTIVITY:

A lot of variation was found in the EC of the samples of the bottle mineral water. Each sample had value quite different from other. EC values of bottle mineral water had a range of 16 to 362 µs /cm with an average of 119.25 µs /cm. as far as samples collected from Residential area of Dhanmondi concern EC range was 81 to 413 µs /cm with mean 269 µs /cm and that of Mohammadpur was of the range 212 to 328 µs /cm with mean 279 µs /cm. the minimum value of EC for slum area 1 and 2 was 236 µs /cm and 528 µs /cm respectively and maximum value was 270 µs /cm and 584 µs /cm respectively. The mean value of EC of Buet hall was 119.25 µs /cm, whereas for vending water samples there were variation with a range of 65 µs /cm to 345 µs /cm with mean 211.9 µs /cm(Table-VII ).

HARDNESS:

The range of hardness of water samples from different areas of Dhaka city was 6 ppm to 304 ppm mean value of 45 samples was 119.69 ppm. Samples collected from residential area-1 was within the range of 106 ppm to 192 ppm with mean value of 126.4 ppm and that collected from residential area-2 was within range of 108 ppm with the average l to 196 ppm with mean 146.4 ppm. In area -1 and area -2 the minimum values were 96 ppm and 98 ppm and the maximum values were 136 ppm and 128 ppm respectively.

The great variety of hardness values were found in bottle mineral water ranging from 6 to 202 ppm with mean 61.4 ppm vending water samples had min and max values of hardness 34 ppm and 164 ppm respectively. The satisfactory higher and almost homogeneous values of hardness were found in residential halls of Buet ranging between 226 ppm to 304 ppm with mean 270 ppm.

CALCIUM:

In all the samples collected from different sectors of Dhaka calcium concentration were between 2.36 ppm to 47.99 ppm with the average of 21.47 ppm while analyzing the samples of residential area-1 the mean value obtained was 31.682 ppm and that of residential area-2 was 24.83 ppm. A great variety of Ca concentration was found in bottle mineral water ranging from

41

2.36 ppm to 47.99 ppm with mean 13.98 ppm (Table VI ). Calcium concentration of vending water was quite homogeneous for most of the samples although ranged from 3.4 ppm to 28.8 ppm with mean 16.65 ppm. The mean value of ca for residential halls of BUET was 24.832 ppm, none of the sample from the city had value aboveWHO permissible values (75 ppm ) rather in case of bottle mineral water. They were too much below the desired value.

MAGNESIUM:

Of the samples collected, the maximum and minimum concentration of mg was 0.02 ppm and 23.32 ppm respectively with the mean of 11.24 ppm . Among the water samples collected all the samples showed value less than 30 ppm which is the lower range of WHO guideline value. The residential halls showed mg concentration ranging from 4.4 ppm to 14.39 ppm with the mean of 8.87 ppm where as comparatively higher value of mg was found in residential area -1 and 2 with the mean value of 10.242 ppm and 15.5 ppm respectively. Although vending water showed variation with the range of 6.1 ppm to 23.32 ppm most lower values were obtained on bottle mineral water. Among the samples of bottle mineral water collected 55.55% samples had concentration less than 1 which was too much low from the guideline values.

ARSENIC:

Arsenic concentration of all the samples collected were much below the acceptable value of who guideline value, although residential area 1 and 2 showed arsenic concentration between 1 to 2 ppb, the vending water and water samples of slum area showed arsenic concentration below 1 ppb. So all the samples were free from arsenic hazard.

5.2: This chapter presents the comparative study of the results obtained from different

category.

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5.2.1: Water samples:

Here water samples collected from slum area 1 and residential area 1 and also vending and bottled water were studied for different parameters and analyzed physically, chemically and bacteriologically. Their comparative study was done using statistics.

5.2.2: Bacteriology:

The samples collected from both the residential and slum areas were found 100% positive for faecal coliform.

5.2.3: EXAMINATION OF WATER QUALITY PARAMETERS:

5.2.3.1: PHYSICO-CHEMICAL ANALYSIS AT SITE:

PH:

The ph values of all the water samples from slum area and residential area ranged from (6.6-6.9) and (6.82-7.05) respectively. (Table I,II,IV,V) . There is significant difference (prob. <.05). The value of confidence interval(95%) for slum area was found to be .228 and the for mean (±) confidence interval was observed 6.532 to 6.988.This showed the water was acidic in nature while confidence interval of residential area was found .188 and range for mean (±)confidence interval was 6.724 to 7.1 and the water was acidic in nature.

Again for bottle mineral water mean value were 7.036 and that for vending water 7.0956. There was significant difference (p<0.05). The value of confidence interval (95%) for vending water was found .362 and the range was 6.73-7.46 which showed water ranges from acidic to alkaline in nature. The value of confidence interval for vending water was .36 and the range mean (±) confidence interval ranged 6.68 to 7.4.

COLOR:

Almost all the samples had color value though less than 15 pt-co units. Water samples from slum area showed more color units than residential area (Table-I &II), although water samples of vending water showed color but bottle mineral water samples were colorless.

ELECTRICAL CONDUCTIVITY:

The minimum and maximum values of EC for slum area were found 236 µs /cm and 270 µs /cm respectively which that for residential area were 212 µs /cm and 328 µs /cm respectively (Table I&II). There was significant difference between residential and slum area (p<.05). the value of confidence interval 95% for residential area was found to be 102.38 µs /cm and the range for mean (±) confidence interval was observed 176.62 µs /cm to 381.38 µs /cm, the value of

43

confidence interval of slum area was 29.54 and the range for mean (±) confidence interval was observed 232.86 µs /cm to 291.94 µs /cm .both the ranges were less than 40 which is the guideline value given by WHO.

The mean value of EC for bottle mineral water was 119.25 µs /cm while that for vending water was 211.9 µs /cm. there was significant difference(p<.05) .the value of confidence interval was observed 222.78 for bottle mineral water and the range mean (±) confidence interval showed the range 0 to 342.03 µs /cm which was below guideline value. The value of confidence interval for vending water was 198.74 µs /cm which showed the range 13.16 µs /cm to 410.64 µs /cm which was above value (400 µs /cm)

HARDNESS:

The mean value of hardness for residential area was found 126.4 ppm while that for slum area was 116.4 ppm. There was significant difference as (p<0.05). The value of confidence interval for residential area was 73.5 which showed the range mean (±) interval as 52.9 ppm to 200 ppm which was too much lower range the guideline value (200 ppm -500 ppm) whereas the value of confidence interval was 23.72 which showed the range 92.68 ppm to 140.12 ppm which showed undesirable range. So the slum water was more soft as compared to residential water but both of them were low the desirable range.

The minimum value of hardness for bottle water and vending water were 6 ppm and 34 ppm respectively while the maximum value was 144 ppm and 164 ppm respectively. There were significant differences between them (p<0.05). The value of confidence interval for vending water was 84.24 which showed the range 5.16 ppm to 173.64 ppm which showed undesirable range. While the value of confidence interval for bottle mineral water was 139.86 ppm which showed the range from 0 to 201.26 ppm. Both of these water samples were undesirable for hardness value.

TURBIDITY:

There was highly significant difference (p<.05) between the water samples from residential and slum area. The confidence value(95%) were 2.34 and 12.56 respectively, which showed the range mean (±) confidence interval 0 to 4.334 NTU for residential area and 0 to 18.7 NTU while the samples from residential area showed lesser turbidity than slum area and slum area range exceeded the who guideline value.

The average value of turbidity for bottle mineral water and vending water was 0.228 NTU and 0.615 NTU respectively. There was highly significant difference between them (P<.05) although both of these are commercial sector. The confidence value (95%) for bottle mineral water and vending water were 0.083 and 1.37 respectively, which showed the range mean (±) interval as

44

0.145 NTU to 0.311 NTU and 0 to 1.99 NTU respectively. This result showed vending water had higher turbidity value than bottle mineral water although both of them were in acceptable range.

5.2.3.2: CHEMICAL EXAMINATION

CALCIUM:

The maximum and minimum concentration of calcium in bottle mineral water was found 47.99 ppm and 2.36 ppm. The mean value found 13.98 ppm while the maximum and minimum concentration of ca+ in vending water were found 28.8 ppm and 3.4 ppm and mean value 16.65ppm. There was highly significant difference (p<0.05). The confidence interval for bottle water and vending water was 31.4 and 17.44 respectively which showed range of mean (±) confidence interval as 0 ppm to 45.38 ppm for bottle water and 0 to 34.09 ppm for vending water. Bottle water had slightly greater concentration than vending water but both of these categories lag too behind the acceptable range.

MAGNESIUM:

The average values of magnesium concentration were found 2.62 ppm for bottle water and 11.7 ppm for vending water. There is no significant difference (p>0.05). The confidence value was found 9.94 for bottle mineral water and 10.78 for vending water. The range mean (±) confidence interval was found for bottle mineral water 0 to 12.56 ppm and for vending water 0 to 34.39 ppm for vending water. Both of these ranges ate too low than the guideline value specified by WHO.

ARSENIC:

There was significant difference (p<0.05) of Arsenic concentration between residential and slum area. The mean value of arsenic was found 1.55 ppb in slum area and 2.15 ppb in residential area. Both these value obtained were too low to cause Arsenic problem.

45

res 1 buet hall slum 1 min.water vended water slum 2 res 20

0.51

1.52

2.53

3.54

4.55

5.56

6.57

7.58

8.59

MEAN VALUE OF PH DATA

PH

standard PH range

FIGURE 5.1:MEAN VALUE OF pH

46

res 1 buet hall slum 1 min.water vended water slum 2 res 20

0.51

1.52

2.53

3.54

4.55

5.56

6.57

7.58

8.59

MEAN VALUE OF PH DATA

PH

standard PH range

res 1 buet hall slum 1 min.water vended water slum 2 res 20123456789

10111213141516

MEAN VALUE OF COLOR(pt-co)DATA

color (pt-co)

standard limit of color

FIGURE 5.2:MEAN VALUE OF COLOR

47

res 1

buet hall

slum 1

min.wate

r

vended

wate

r

slum 2

res 2

0123456789

101112

MEAN VALUE OF TURBIDITY (NTU) DATA

turbidity (NTU)

standard limit of turbidity

FIGURE 5.3: MEAN VALUE OF TURBIDITY

48

res 1

buet hall

slum 1

min.wate

r

vended

wate

r

slum 2

0

50

100

150

200

250

300

MEAN VALUE OF COMBINED HARDNESS DATA

HARDNESS (ppm as CaCO3)

standard value of lower limit for hardnessFIGURE 5.4: MEAN VALU OF HARDNESS

49

res 1 buet hall min.water vended water res 20

10

20

30

40

50

60

70

80

MEAN VALUE OF COMBINED Ca++

Ca++ (ppm)

standard value for Ca++

res 1 buet hall min.water vended water

res 205

10152025303540

MEAN VALUE OF COMBINED Mg++ DATA

Mg++ (ppm)

standard value of lower lomit for Mg++

FIGURE 5.5: MEAN VALUE OF CALCIUM

50

res 1 buet hall min.water vended water

res 205

10152025303540

MEAN VALUE OF COMBINED Mg++ DATA

Mg++ (ppm)

standard value of lower lomit for Mg++

res 1 buet hall slum 1 min.water vended water slum 2 res 20

100

200

300

400

500

600MEAN VALUE OF EC (uS/cm) DATA

EC (µS)

FIGURE 5.7: MEAN VALUE OF EC

CHAPTER 6

HEALTH RISK ASSESSMENT

6.1: ASSESSMENT OF HEALTH EFFECTS

In this chapter the health effects of different parameters of water quality analyzed in this study is represented and also their degrees of severity in different consumer category are also discussed depending on the results obtained from the study.

6.2: HEALTH EFFECTS OF pH

The pH is of major importance in determining the corrosive quality of water. Although pH has no direct impact on the water consumers it is one of the most important operational quality parameters .Careful attention to pH control is necessary at all stages of water treatment to ensure

51

satisfactory water clarification and disinfection. For effective disinfection by chlorine, the pH should preferably be less than 8. The pH of water entering the distribution system must be controlled to minimize the corrosion of water mains and pipes in household water system .failure to do so may result in the contamination of drinking water and in adverse effects on its taste, odor and appearance.

The pH is a critical factor in determining the nature of the interactions with some of the transition and heavy metal ions (WNAS, 1997). The pH of water affects the toxicity of various compounds by changing the ionization equilibrium which may cause health hazard.

In this study of the water samples pH values were within the range given by WHO, which ensured no adverse effects due to pH.

6.3: HEALTH EFFECTS OF TURBIDITY

The consumption of highly turbid water may constitute a health risk (Schwartz et al 1997) because excessive turbidity can protect pathogenic organisms from the effect of disinfectants , stimulate the growth of bacteria in the distribution system and increase chlorine demand .In addition ,the adsorptive capacity of some particulates may lead to the presence of harmful organic and inorganic compounds in drinking water .Any turbidity in drinking water is automatically associated with possible sewage pollution and the health hazards occasioned by it. This fear has a sound basis historically, as any one knows who is familiar with the water borne epidemics.

Failure to removal of turbidity effectively usually results in short filter runs and production of inferior quality of water.

In this study the maximum and minimum turbidity observed were 6.19 NTU and 0 NTU respectively which was below the guide line value given by WHO. So the studied areas are safe from turbidity related diseases.

6.4: HEALTH EFFECTS OF COLOR

Pure water should not possess any color because color is the indication of the presence of various impurities .Colored water is not always harmful to man, but in most of the cases it is .Even if the water is not harmful, people for aesthetic reasons do not prefer it. Limiting the color in potable water means limiting the concentration of the undesirable substances that are complex with or absorbed on to humic substances .Color present in higher concentration may increase the toxicity of water.

52

In this study the higher concentration of color was observed in the water samples collected from slum water (13 pt –co) and minimum were in the mineral water samples which were colorless. Residential water samples were satisfactory regarding color values.

6.5: HEALTH EFFECTS OF ELECTRICAL CONDUCTIVITY

Much of the health effects are not known regarding the electrical conductivity but a acceptable value of it for drinking water is generally considered as 400μs/cm. All the samples except that from the residential halls of BUET were below this range.

6.6: HEALTH EFFECTS OF HARDNESS

The hardness of water relates to the amount of calcium, magnesium and sometimes iron in the water. The more minerals present, the harder the water. Soft water may contain sodium and other minerals or chemicals; however, it contains very little calcium, magnesium or iron.

Bokina (1995) reported that extremely hard drinking water might lead to an increased incidence of urolithiasis . It was observed that there was association between death rates from strokes and level of pollutants in drinking water .Yang (1998) reported that many studies have demonstrated negative association between mortality from cardiovascular diseases and water hardness. The results of the study by Yang (1998) showed that there is a significant protective effect of magnesium intake from drinking water and on the risk of cerebrovascular disease. In another study of Yang et al (1997) showed a significant negative relationship between drinking water hardness and gastric cancer mortality.

Statistically negative relationship between the hardness of drinking water supplies and cardiovascular diseases (CVD) mortality data (i.e. the lower the hardness of drinking water the higher the standardized mortality ratios (SMR))

In Taiwan, two similar investigation revealed by Yang et al (1999) and his team showed significant negative relationship of rectal cancer and esophageal cancer mortality with drinking water hardness.

In this study the hardness values were found very low except in the water samples collected from the residential halls of BUET. The lowest values of hardness were observed in the bottle mineral water. Some brands such as ‘ACME’, ‘PRAN’, and ‘FRESH’ were found to have hardness below 10 ppm. Even the brand ‘SHANTI’ which is the product of DWASA was found to have hardness 20ppm. And all the other samples tested were also too below to cause the diseases as stated above.

53

6.7: HEALTH EFFECTS ASSESSMENT OF ARSENIC AND FECAL COLIFORM

Microbial and arsenic are major contributors to the disease burden in Bangladesh. In this study they were analyzed using APSU QHRA model .First the individual health effects are described.

6.7.1: HEALTH EFFECTS OF ARSENIC

In a recent study by the National Institute of Preventive and Social Medicine (NIPSOM)

Arsenic related diseases (arsenicosis) have been identified in 37 districts (Ahmed et al.1998) a total of 6000 cases were identified in 162 villages in 37 districts, mostly in the rural areas. Three stages of manifestation of chronic arsenicosis were observed in the study (Ahmed et al.1998) .But most of the cases were found in the first and second stages .The most common presentations were melanosis , keratosis, hyperkeratosis and depigmentation. Cancers were found among 0.8% and actinic keratosis and Bowen’s diseases were observed among 3.1 % of the cases . Apart from these ,respiratory, pulmonary, cardiovascular, gastrointestinal ,hematological, heptic, renal, reproductive ,immunological, genotoxic, mutagenic effects of ingestion have been reported.

It is important to note that the improvement of the patients was found who stopped taking arsenic contaminated water and increased intake of protein rich food, vitamin A, E, and C.

The occurrence of skin and other cancers due to ingestion of arsenic contaminated water have been well documented in Taiwan. Arsenicosis cases have been reported in thousands from Bangladesh and west Bengal. Arsenicosis cases have also been reported from china, Inner Mongolia, Nepal and Pakistan.

54

FIGURE 6.1: DERMAL EFFECT OF ARSENIC

Hence the following table summarizes the effects.

Table 6.1: Toxicological effects due exposure to high arsenic concentration in drinking water (WHO, 1996, khan, 1997)

Effect Symptoms Remarks Blackfoot diseaseArsenic dermatosis

Dermal lesion ,peripheral neuropathy ,keratosis,hyperkeratosis,hyperpigmentation

May necessitate operation

None specific Nausea, abdominal pain ,Diarrhoea , vomiting, conjunctivitis ,Oedema

Mainly due to acute toxicities

Pregnancy disorder Spontaneous abortions ,miscarriages Heart disease Coercion of aorta, cardiovascular disturb Among childrenCancer Bladder ,kidney ,skin and lungs, liver and

colonMortality Mainly due to cancer

55

6.7.2: HEALTH EFFECTS OF FECAL COLIFORMS

Poor quality of water continues to pose a major threat to health .Diarrhoeal diseases contributes a huge global disease burden. According to world health organization (2004 a)

●1.8 million people died every year from diarrheal diseases (including cholera ),90% are children under 5 ,mostly in developing countries ,88% of diarrheal disease is attributed to unsafe water supply and sanitation .

●Improved water supply reduces diarrheal morbidity by between 65 and 25 %, if sever outcomes are included.

●Improvement in drinking water quality through household water treatment, such as chlorination at point of use, can lead to a reduction of diarrhea episode by between 35% and 39%.

● Each year 36000 children under 5 die of diarrhea.

● Children under five suffer from 3-5 episodes of diarrhea each year and suffer 2-3 days and sometimes more than 2 weeks resulting in severe dehydration, malnutrition, which may cause death.

● The physical and mental development of the children are greatly retarded by diarrhea. Children may suffer from vitamin A deficiency after diarrheal attack.

The most common and wide spread health risk associated with drinking water is microbial contamination, the consequences of which mean that its control must always be of paramount importance.

6.8: USE OF APSU QHRA MODEL

The APSU QHRA model provides a prediction of disease burdens associated with water supplies based on reference pathogens and arsenic. Disease burden has been expressed in disability adjusted life year (DALY) as recommended by WHO (2004b) .Arsenic DALYs have been estimated considering skin, lung ad bladder cancers as end points. Microbial DALYs were estimated 3 reference pathogens (a composite model bacterial pathogen, rotavirus, and Cryptosporidium parvum).

56

DALYs are calculated using E .coli ( or thermotolerant coliform )concentration as input data and the relationship between these organisms and the reference organism has been derived from the long term observation of the sewage . The arsenic and microbial DALYs of the concerned water supply are estimated and added to determine the total DALY.

This model was used because the model can estimate the disease burden from a single measurement of microbial quality. The more data used the more accurate the result would be. This model was especially developed for use in the context of Bangladesh.

57

6.9: HEALTH RISKS ASSESSMENT USING THE MODEL

6.9.1: RESIDENTIAL AREA 1

Viral and bacterial disease burden were predicted to be a greater proportion of the total DALYs . Arsenical burden has almost no contribution to the total DALYs and is well below the guideline values both for 10 µg/l and 50 µg/l arsenic GV. The water samples are subjected to more microbial related health risk than arsenic.

Figure 6.2: Illustration of disease burden of residential area 1by APSU QHRA model

58

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6.9.2RESIDENTIAL AREA 2 (DHANMONDI):

Of the total burden viral burden was predicted to be of greater proportion. Bacterial burden has some proportion in the total DALYs but bacterial burden has negligible impact. Virus, bacterial and protozoa burden were found to be greater than the specified guideline value. The microbial burden has wide range as compared to arsenic which has very narrow range. The scenario of arsenical burden was found to be less than both the guideline value. So, the water samples have no risk as far as arsenic hazard is concern.

Figure 6.3: Illustration of disease burden of residential area 2 by APSU QHRA model

59

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6.9.3: SLUM AREA 1(MOHAMADPUR GENEVA CAMP)

Both viral and bacterial burden have significant contribution to the total DALYs. They are significant than the protozoal burden although all three of them have burdens greater than the guideline values. Bacterial and protozoal burden has wider range . Arsenical burden has very narrow range and is less than the guideline value. So the samples are safe from the health risk due to arsenic.

Figure 6.4: Illustration of disease burden of slum area 1 by APSU QHRA model

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6.9.4: SLUM AREA 2(BESIDE DHAKESHWARY TEMPLE)

Viral burden has the greater contribution to the total burden as compared to the bacterial or protozoa burden. But all of them have values greater than the guideline value. The arsenical burden is well below all the guideline values. So the water samples are safe from arsenical health hazard but pose some health risk due to microbial contamination.

61

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FIGURE 6.5: ILLUSTRATION OF DISEASE BURDEN OF SLUM AREA-2 BY APSU QHRA MODEL

6.9.5: VENDING WATER

Viral, bacterial and protozoa burden is more than the guideline values. Arsenic burden is well below the guideline value and do not pose any health risk. Vended water which is supplied with the assurance of pure water is not safe as it has microbial contamination.

Figure 6.6: Illustration of disease burden of Vending water by APSU QHRA model

62

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6.9.6: BOTTLE MINERAL WATER

Viral burden has the greater contribution to the total burden and poses more risk than protozoa and bacterial burden. Arsenical burden is much lower than the guideline values. Although the bottle water is expected to be safe from both the microbial and arsenic burden, but the samples collected shows that the bottle water samples are free from arsenic contamination , but poses health risk due to microbial contamination.

Figure 6.7: Illustration of disease burden of bottle mineral water by APSU QHRA model

63

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6.9.7: WATER SAMPLES FROM BUET

Viral, bacterial and protozoa burden ranges are very close to the guide line. The most common and widespread health risk associated with drinking-water is microbial contamination, the consequences of which mean that its control must always be of paramount importance. Priority needs to be given to improving and developing the drinking water supplies that represent the greatest public health risk. Microbial contamination of major urban systems has the potential to cause large outbreaks of waterborne disease. Ensuring quality in such systems is therefore a priority values for safe drinking water. So from microbial point of view the water samples are safe. Arsenical burden is also below the guideline value. So the collected water samples are safe from both microbial and arsenical health hazard.

Figure 6.8: Illustration of disease burden of BUET residential halls by APSU QHRA model

64

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CHAPTER 7

DISCUSSION

65

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The present study was planned to monitor the quality of water consumed by the population of Dhaka city for drinking purposes and the impact of the quality of water on health. The population constituted all classes of people including the low income class in the slum area who had to consume water even though the quality was poor because they could not afford bottled or vending water from the market.

Water samples collected from different consumer categories were found unsatisfactory as many of the parameters were found not conforming to the standards of WHO. Even treated water is not present even in clinics as some samples of vending water was collected from clinics (table VII) which showed the evidences of microbial contamination.

Quality of drinking water in Dhaka city is a burning issue now a days, which can be observed in our newspaper also. An article published in newspaper ( Prothom Alo on 25.08.08) revealed that water supplied by Dhaka WASA had severe odor, color and suspended solids. Even samples collected from some areas showed coliform bacteria even up to 500 per 100 ml of sample according to the article. The reasons mentioned were old and defective water supply lines and the exposure of water supply lines to the sewerage lines in many areas. The article also mentioned that the bottle mineral water is also contaminated.

Another article published in the daily news paper (Amar desh on 19.02.09) gave a statement on behalf of the officers of Dhaka WASA that the water due to addition of excess amount of chlorine for treatment of high pollutant load may contain some color or odor but it is safe and do not contain any harmful pathogenic microorganism that may cause any health hazard . But in our study we found evidences of microbial contamination in water supplied by Dhaka WASA in slum area even to the level of TNTC (too numerous to count)

There are many reasons of bacteriological contamination of water at domestic level or consumer end other than stated by the article. Usually most of the houses or buildings in Dhaka city are constructed through contractors and the materials used are not good resulting in the cracks of water reservoirs. Due to shortage of water

66

several people have installed motors for pumping of extra water in addition to routine supply and it allows the sewage contamination along with drinking water.

In our study the greater bacterial contamination was found in the water samples collected from residential areas and slum areas. In both areas water from the distribution network was collected in the storage reservoir. In residential areas the storage reservoir was underground and in slum areas the water was collected in open tank.

Distribution system is especially vulnerable to contamination when the pressure fails, particularly in the intermittent supplies of many cities in the developing countries. Suction is often created by direct pumping from mains to private storage tanks, a practice that should be minimized. Underground storage tanks and service reservoirs must be inspected for deterioration and for infiltration of surface and ground water. It is desirable that the underground storage reservoir should be fenced off to prevent access of human and animals and to prevent the damage of the structures.

Repair works of the main is another possible source of contamination. If the main has been damaged and there is a possibility that waste water from the fractured sewer or drain have been reentered the situation is most serious. The action that must be taken to protect the consumers from water borne diseases should be specified in national codes of practice and in local instruction to water works.

In their report after testing the samples of bottle water of country´s seven companies by the department of soil, water and environment of Dhaka university , the Consumers Association of Bangladesh (CAB)reported in September 2004 that there is no trace of mineral and most other ingredients inscribed on the bottled “mineral water ’’. The tested brands were ‘Mum’, ‘Aqua’, ‘Pran ‘‘Duncan’,’Fresh’,’Libra’ and ‘Jibon’ .The fact remains that the water consumed in the production line are either deep tube well based underground water (treated or untreated ) or simply the tap water supplied by WASA. It was also evident in their tests that the water was not even boiled and found to contain coliform bacteria. The report added that in ‘Mum’,’Aqua’, ‘Pran ‘’Fresh’,’Libra’ and ‘Jibon’ hardness was under the approved level., the production of pH was less than the level

67

prescribed by the World Health Organization (WHO) in all the brand tested except the ‘Duncan’. All the products are acidic which is stated to be injurious to health.

In our study we tested ten mineral water samples ‘Shanti’,’ Acme’,‘Spa’, ’Jibon’ ,’Pran’,’Mum’,’Fresh’’,Libra’,’Fyne’,’Duncan’ . In all the brands the hardness was under the approved level. It was due to the treatment process adopted by them.(tableX). Most of the companies use Reverse Osmosis and Ozone technology as purification system which reduces the hardness as well as calcium and magnesium concentration which is related in causing cardiovascular diseases. In our investigation we do not find bacterial contamination in any of the brands. ‘Pran’ and ‘Mum’ was acidic in nature and pH of other brands was acceptable range. Whereas electrical conductivity, color, arsenic concentration were in the satisfactory range for all the brands.

Generally in drinking water hardness is in the range of 200-500 mg of calcium carbonate per liter as given by Bangladesh standard (ECR, 1997) except the water samples from the residential halls of BUET, no other samples conformed to the acceptable range.

The calcium and magnesium concentrations found in the water samples were below the WHO guideline value (Table-VIII) but the lower concentration is associated with health risk (as discussed in chapter-6) although there were significant differences (p<0.05) between different consumer category except the magnesium concentration of vending water and bottle water where there was no significant differences (p>0.05) between the two.

According to the European Economic Community Standards for physico- chemical samples ranging from chemical parameters in relation to the natural water structure, guide level of electrical conductivity (EC) is 400µs/cm (AWWA,1990) . Again the maximum permissible level of conductivity in drinking water is 500 µs/cm as provided by Jaffer et al(1998). A lot of variation of the sample was found in the range from 16 µs/cm to 570 µs/cm. higher range of the EC values were observed in the residential halls of BUET ranging from 427 µs/cm -570 µs/cm exceeding the maximum range. EC of any samples depends entirely upon the salts dissolved in it and it increases or decreases with the change in the amount

68

of the solids in the solution. The variation may be due to the changes taking place in the distribution network as well as in the source.

High turbidity values found at the consumers end must be due to the re suspension of sediments in the distribution system (WHO, 1996). Another reason may be the storage of water prior to usage and tank cleaning is not a usual practice. In our study turbidity values were higher in the slum area -1(maximum 6.19 NTU ) and residential area-1 ( maximum 3.73 NTU ) which may be due to the above reasons. Although the turbidity values were within the acceptable range.

Most of our sample showed color ranging from 0-13 pt-co units. The samples collected from the slum area 1 and 2 showed higher values than any other samples. The color of drinking water is usually strongly influenced by presence of iron and other metals, either as natural impurities or as corrosion products. It is known that the organic coloring material in water stimulates the growth of many aquatic microorganisms (WHO, 1996) therefore the source of color in the water supply should be investigated.

Arsenic concentrations in all the samples were much lower than the guide line value. The health risk assessment done by APSU QHRA model showed no health risk associated with arsenic concentration as analyzed in chapter-6, but it showed high risk associated with microbial contamination of the studied area.

Drinking water quality is a major concern of Dhaka city now a days. To modernize the water supply system and to ensure quality of drinking water extensive plans have to be taken by government as early as possible.

69

CHAPTER 8

CONCLUSION AND RECOMMENDATION

70

8.1: The study has yielded some useful information about the drinking water quality in Dhaka

city and also the health hazards that can result from the consumption of this water.

8.2: The important findings are as below:

● The quality of drinking water of BUET residential halls was better than the government supply.

● In these study 45 samples were analyzed from different consumer category .Except the bottle mineral water the microbial contamination was found in all the samples. The worse condition was found in the slum area.

● Water samples from vendors and residential areas showed higher concentration of fecal coliform .

● Evaluation of physicochemical analysis showed non satisfactory results as hardness, calcium and magnesium concentration of all the samples except BUET residential halls were too low than the standard given by WHO.

● Commercial supply such as vending water and bottle mineral water were not safe as vending water were found to contain fecal coliforms and bottle mineral water were found to have inadequate hardness.

● The diseases that may result due to consumption of this water are urolithiasis , cerebrovascular and cardiovascular disease ,diarrhea , gastric cancer, rectal cancer and esophageal cancer etc.

● The highest risk associated is due to microbial contamination as arsenic concentration was too low to cause hazard.

● By comparing the economic status of the consumers it was found that the slum dwellers consumes inferior quality water and they are at the highest risk.

71

8.3: The following are the recommendation for improving the water quality

●Periodic estimation of some important parameters like bacterial load especially indicating fecal coliforms,, turbidity, temperature, pH , ammonia , nitrate, nitrite , DO,PO4 both at the source and at the consumers end must be carried out.

●Better treatment processes for ensuring the safe drinking water must be ensured.

Public health and personal hygiene about the potable water safety and its hazards must be publicized.

● Strong policy and law should be enforced to ensure the quality of the bottle mineral water and vending water.

●The reservoirs should be cleaned periodically (ideally every two months for Bangladesh situation).

●To prevent cross contamination water and sewerage pipelines should not be in close vicinity.

●Old pipelines should be replaced at the earliest.

●More treatment plants are needed and should be located at the shorter distances from the consumers end.

●Urban poor deserve special attention as almost 25-30 % of the city population live in the slums and do not have the adequate access to the safe water.

72

BIBILIOGRAPHY

73

APHA, AWWA,WEF,(1998), Standard Methods for the Examination of Water and Wastewater , 20th edition .

AWWA , (1990) Water Quality and Treatment; A Handbook of Community Water Supply 4 th

edn, McGraw Hill, Inc.USA

Ahmed , M.F (2006 ) ,Shamsuddin SAJ ,Mahmud SG , Rashid H, Deere D , Howard G. Quantitative Health Risk assessment for arsenic and microbial contamination of drinking water .APSU .

Ahmed , M.F, Rahman Mujibur .Water supply and sanitation .ITN-Bangladesh .

Aziz ,M.A (1975), Water supply engineering , Hafiz Book Centre, Dhaka

Baloch, M.K .,Jan ,I.U., Ashour, S.T.(2000) Effect of septic tank effluents on quality of ground water ,Pakistan Journal of food science,10,3-4,25-31

Boulay , N, Edwards, M .(2001) Role of temperature ,chlorine and organic matter in copper corrosion by product release in soft water , Water Research, 35,3.683-690.

Bjorvatn, K., Bardsen. A., Reimann C., Morland, G., Skarphagen, IL., saether, O., Siewers, U., Hail. g., Strand. T. (1997) Ground water and health, Reflections based on analysis of water specimens from Hordaland and Vestfold. Tidsskr Nor Laegeforen.117,1,62-65.

Holt. M.S.(ed.), Eisenbrand , G . ( ed.) , Hofer . M . (ed). Kroes . R . (ed) . Shuker .L.(ed.) (2000) Sources of chemical contaminations and routes into the fresh water environment . Food and Chemical technology , 38, S21-S27 .

Huang .G.H ., Xia , J. (2001) Barriers to sustainable water quality management , journal of environment management 61,1,1-23.

Iwami , O .,watanabe .T., Moon , C.S., Nakatsuka , H. ,Ikeda , M.(1994) Motor Neuron disease on the kii Peninsula of Japan excess- excess manganese intake from food coupled with low magnesium in drinking water as a risk factor . Science of Total Environment , 149,1-2 ,121-135 .

Jaffer . M. , Ashraf , M., Rasool , A. (1988) Heavy metal contents in some selected local fresh water fish and relevant waters Pak . J . Sci. Ind. Res., 31 : 189-193.

Khan ,K..Khan,M..,Amin..Khattak,M.A..,E.R..(1993)monitoring of pollution of water of N.W.F.P. Pakistan .Journal of physical chemistry ,1,7790.

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Le chevalier . M.W. Welch , N.J. , Smith , D. B (1996) Full –scale studies of drinking water . Applied and Environmental Microbiology , 62 , 7 , 2201-2211 .

Lehloesa L.J..Muyima.N.Y.O.(2000) Evaluation of the impact of household treatment procedures on the quality of ground water supplies in the rural community of the Victoria district . Eastern Cape : technical note . water SA.26,2,285-290

Morris , R.D ., Naumova , E . N ., Levin , R., Munasinghhe. R.L. , (1996) temporal variation in drinking water turbidity and diagnosed gastroenteritis in Milwaukee , American Journal of Public Health , 86, 2, 237-239 .

Power , K. N. , Nagy , L. A. (1999) Relationship between bacterial re-growth and some physical and chemical parameters within Sydney ‘s drinking water distribution system , Water Research 33,3,741-750 .

Raucher , R.S (1996) Public Health and regulatory consideration of the safe drinking water act.

Annual Reviews Public Health , 17 ,179-202 .

Sisti , M. , Albano , A., Brandi. G (1998) Bactericidal effects of chlorine in motile Aeromonas spp . in drinking water supplies and influence of temperature on disinfection efficiency. Letters in applied microbiology .26,5,347-351.

WHO (1993) , Guidelines for Drinking Water Quality ( 2nd ) edition ), World health Organization , Geneva , Switzerland

Yang ,C.Y., (1998) calcium and magnesium in drinking water and risk of death from cerebrovascular diseases, stroke , 29, 2.411-414

Yang ,C.Y., Cheng , M. F., S.S ., Hsieh .Y.L ,(1998) calcium, magnesium and nitrate in drinking water and gastric cancer mortality . Japanese Journal of cancer research , 89,2,124-130 .

Yang ,C.Y., Tsai S. S,lai T.C. Chung-Feng Hung . C.F. , Chiu. H. F. (1999 a) Rectal cancer mortality and total hardness levels in Taiwan’s drinking water . Environmental research , 80,4,311-316.

Yang ,C.Y., Chiu. H. F. chenga , M. F ., Tsai S.S, Hung C.F . in M.C (1999 B) Esophageal cancer mortality and total hardness levels in Taiwan’s drinking water . Environmental research , 81,4,302-308.

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APPENDIX

76

TABLE I: Test results of residential area 1

Parmeter Sample 1 Sample 2 Sample 3 Sample 4 Sample 5Hardness (ppm) 112 110 106 192 112

Calcium (ppm 27.66 27.87 27.2 45.82 29.86Magnesium(ppm)

9.29 9.36 9.21 14.54 8.81

pH 6.96 7.05 6.89 6.84 6.82EC(µs/cm) 328 324 290 241 212Turbidity (NTU) 2.57 3.73 0.73 1.56 1.38

Color (pt-co) 5 7 3 7 10

Arsenic(ppb) 1.56 3.41 1.93 1.83 2.02Fecal coliform (per 100 ml )

1.38 67 22 20 55

TABLE II: Test results of residential area 2

Parmeter Sample 1 Sample 2 Sample 3 Sample 4 Sample 5Hardness (ppm) 196 108 192 110 126

Calcium (ppm) 42.86 27.39 46.31 27.83 32.48Magnesium(ppm)

21.45 9.59 18.5 9.81 18.16

pH 6.89 7.1 7.04 7.2 7.28EC(µS/cm) 291 81 413 311 249Turbidity (NTU) 1 1.1 1.05 1.09 2

Color (pt-co) 4 7 4 3 5

Arsenic(ppb) 0.8 0.39 0.72 0.95 0.69Fecal coliform (per 100 ml )

49 4 10 65 11

77

Table III: Test results of residential halls of BUET

parmeter Sher e bangle

Ahsanullah Titumir Sohrawardy 4

Chatri hall

Hardness (ppm) 304 226 296 294 230Calcium (ppm) 22.27 27.76 38.65 21.19 14.29Magnesium(ppm)

8.64 9.43 14.39 7.49 4.4

pH 6.61 6.57 6.55 6.54 6.66EC(µs/cm) 570 427 562 593 436Turbidity (NTU) 0.8 0.27 0.32 0.23 0.26

Color (pt-co) 4 3 8 4 3

Arsenic(ppb) 1.73 0.88 1.22 1.37 1.08Fecal coliform (per 100 ml )

0 0 0 0 0

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Table IV : Test results of slum area1

parmeter Sample 1 Sample 2 Sample 3 Sample 4 Sample 5Hardness (ppm) 112 124 98 120 128 pH 6.6 6.8 6.7 6.8 6.9EC(µs/cm) 270 269 236 268 269 Turbidity (NTU) 6.19 16.7 1.64 1.21 4.94

Color (pt-co) 3 13 5 7 9

Arsenic(ppb) 1.85 1.85 1.25 1.47 1.32Fecal coliform (per 100 ml )

38 20 30 60 160

Table V: Test results of slum area2

parmeter Sample 1 Sample 2 Sample 3 Sample 4 Sample 5Hardness (ppm) 124 108 96 118 136pH 6.63 6.68 6.73 6.8 6.82EC(µs/cm) 521 584 536 533 528Turbidity (NTU) 1 0.1 0.21 0.19 0

Color (pt-co) 1 5 5 6 10

Arsenic(ppb) 0.39 0.25 0.32 0.48 0.23Fecal coliform (per 100 ml )

TNTC 0 0

79

Table VI : Test results of Bottle Mineral water

parameter

AC

ME

SH

AN

TI

SP

A

JIB

ON

PR

AN

MU

M

FR

ES

H

LIB

RA

FY

NE

DU

NC

AN

Hardness (ppm)

6 20 144 40 8 126 6 42 20 202

Calcium (ppm)

2.36 7.92 32.24 11.55 3.15 48 2.36 10.77 7.54 32.24

Magnesium(ppm)

0.02 0.05 15.39 2.7 0.03 1.46 .02 3.66 0.28 28.33

pH 7.03 7.15 7.05 7.2 6.8 6.6 7.05 7.1 7.3 7.05EC(µs/cm)

122 58 362 95 16 261 46 146 46 40.5

Turbidity (NTU)

0.19 0.27 0.21 0.25 0.16 0.29 0.21 0.27 0.20 0.23

Color (pt-co)

0 0 2 0 0 0 0 0 2 0

Fecal coliform (per 100 ml )

0 0 0 0 0 0 0 0 0 0

80

Table VII : Test results of vending water

parameter

Ap

ang

Sab

eel

nil

giri

nia

gra

enu

eres

t

Pu

reW

ater

com

pan

y

Rel

iab

le

pu

re

dri

nk

ing

wat

er

Ah

ad c

omp

any

Sh

amim

w

ater

su

pp

ly

Dro

ps

d

rin

kin

g w

ater

Hardness (ppm)

85 76 110 106 48 164 132 102 34 37

Calcium (ppm

17.1 14.6 20.5 23.33

8.45 28.8 25.4 20.2 3.4 4.73

Magnesium(ppm)

10.27

9.59 14.27 11.61

6.53 23.32 16.61 12.48 6.19 6.11

pH 7.3 7.28 7.21 7.02 6.86 7.12 7.22 7.26 7.37 7.21EC(µs/cm)

236 220 213 345 128 341 283 218 65 70

Turbidity (NTU)

0.32 0.19 0.42 0.66 0.36 0.30 0.79 0.27 0.35 2.49

Color (pt-co)

6 9 3 7 7 8 10 7 8 10

Arsenic(ppb)

1.2 0.85 0.92 0.95 1.05 1.28 2.43 0.97 0.43 2.15

Fecal coliform (per 100 ml )

26 0 16 1 200 9 47 20 31 18

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TABLE VIII: WHO GUIDELINE VALUES (2004)

PARAMETERS GUIDELINE VALUESHARDNESS(ppm) 200-500CALCIUM(ppm) 75MAGNESIUM(ppm) 30-35pH 6.5-8.5EC(µS/cm) <400TURBIDITY(NTU) 10COLOR(pt-co) 15ARSENIC(ppb) 50FECAL COLIFORM(per 100 ml) 0

82

TABLE IX: SAMPLES LOCATION AND DESIGNATION

A: RESIDENTIAL AREA-1 (BABAR ROAD,MOHAMMADPUR)

ADDRESS DESIGNATION20/24, Babar road. SAMPLE 113c/2c, Babar road. SAMPLE 220/28, Babar road. SAMPLE 320/34a, Babar road. SAMPLE 413c/10c, Babar road. SAMPLE 5

B: RESIDENTIAL AREA-2(DHANMONDI)

ADDRESS DESIGNATIONBhuttu tower(8A/7,road no.13) SAMPLE 41Ivory crest(8A/10,road no.13) SAMPLE 42Adel corner(8A/2,road no.13) SAMPLE 43Aditya (8A/5,road no.14) SAMPLE 44Holy height (8A/12,road no.14) SAMPLE 45

83

TABLE X: PRODUCTION PROCESS OF MINERAL WATER

SN. company name Production process

1 Acme Acme drinking water is treated by Reverse Osmosis, Ultraviolated& Ozonated.

2 shanti Shanti Pure Drinking water is hygenically processed by automatic machine and bottled under strict quality control.Reverse Osmosis (RO) system followed for purification.

3 Spa Spa drinking water is treated by Reverse Osmosis, Ultraviolated& Ozonated.

4 Jibon Jibon natural mineral water is produced under strict hygienic conditions in a modern water treatment plant. Water is drawn from a depth of 600 ft, purified by GERMAN OZONE TECHNOLOGY and filtered by a REVERSE OSMOSIS SYSTEM, which completely remove toxic substances from the water such as arsenic, lead, mercury cyanide, and micro organisms. This water is bottled in pet bottle, which is approved by F.D.A USA for food packaging.

5 Pran 100% Germ free, Hygienically processed, Water drawn from 450 ft depth, Sterized by German Ozone Technology. Bottling and capping by fully automatic machine.

6 Mum Mum Natural Drinking Water confirms to WHO and BSTI guidelines. It is rich in minerals,well-balanced and ideal for people for all ages.

7 Fresh Super Fresh drinking water is treated by Reverse Osmosis, Ultraviolated& Ozonated. Super Fresh contains valuable minerals which your body needs every day. This Water is packed in pet bottle, which is approved by F.D.A USA for food packing.

8 Libra Libra drinking water is treated by Reverse Osmosis, Ultraviolated& Ozonated.

9 Fyne Fyne drinking water is treated by Reverse Osmosis, Ultraviolated& Ozonated.

10 Duncan Duncan drinking water is treated by Reverse Osmosis, Ultraviolated& Ozonated.

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