Water Quality Management Issues In DEWA Company Environmental Sciences Essay

This paper will discuss water quality management issues in a Dubai company called DEWA (Dubai Electricity and Water Authority). This is a governmental organization that is in charge of producing and distributing water and electricity to the whole of the Dubai population. Water quality issues were among the concerns of the third UNEP report on the environment. Gordon (1998:1) notes, “The Global Environmental Outlook (GEO-3 report) identified a wide spectrum of existing and emerging water issues that need to be addressed if the world is to achieve sustainable development.”

One of the general issues in water management is the threat of depletion of groundwater due to the rising demands for land for agriculture and for building urban centres. Majority of communities living near water catchment areas such as forests are depleting rather than preserving them. Hydro-development and geothermal projects are another threat to abundance of water sources and the quality of water because they divert it to uses such as irrigation and generation of electricity. Another concern is the threat to quality of water due to pollution by fertilizers, pesticides and factory chemical emissions.

Poor quality of water has a negative effect on human, animal and plant populations, and can occur due to natural or artificial factors. One cause of problems in the quality of water is natural chemicals in the air and ground that enter into contact with water sources and pollute them. Another factor, which is also the largest contributor to poor water quality, is human use of chemicals that pollute water bodies in activities such as farming and industrial production. Sources of water pollution can be fixed, such as manufacturing plants, or mobile, for example, farming activities. The first category has pollutants that are very strong while those of the latter group are mild but are extensive in area of coverage. Moreover, it is easier to estimate and alleviate pollution from the first category than the second because the latter affect a wider region.

As Ongley (1999:5) observes, “Water quality degradation can pose serious threats to public health, agricultural and industrial production, ecological functions, and biodiversity. Water quality problems can arise from high concentration of naturally occurring elements such as arsenic, fluoride, or selenium. But most water quality problems are caused by the discharge of pollutants from human activities. Pollution sources include point sources-specific points of discharge of high-pollutant concentration-and nonpoint sources-low-concentration sources covering a large area. Point source discharges from sewers, wastewater treatment plants, and factories are visible and can be chemically characterized relatively easily. However, substantial loads of pollutants can also enter water bodies from nonpoint sources, such as fertilizer use for agriculture.”

In the case of the DEWA Company, poor quality of water is likely to result from emissions from point sources rather than nonpoint ones because the firm undertakes the supply of water to the nation. Consequently, the company has facilities set up to clean water before pumping it to consumers. For example, in 2010 the company set up a facility at Jebel Ali to purify water from salty substances. The chemicals used to desalinate the water and purify it may be a threat to its quality.

Another possible threat to the quality of water that the firm supplies is likely to be poor hygiene of the storage tanks, distribution pumps and pipes. If management does not ensure that these facilities are clean, contamination of water is likely to occur. If the storage tanks are left bare, contamination of the water contained therein is likely to occur. Moreover, the residue of chemical substances, especially chlorine, used to clean these facilities is likely to pollute the water when in storage or during distribution. In addition, the company can cause pollution of external water masses through emissions from its water treatment facility. At the same time, since it supplies electricity to consumers, generation of this source of energy can cause gas emissions that pollute not only the air but also the water masses nearby.

The World Health Organization has set maximum levels for chemicals present in water, especially for human consumption. World Health Organization (1958: 9) “Water intended for human consumption must be free from chemical substances and micro-organisms in amounts which would provide a hazard to health is universally accepted. Supplies of drinking-water should not only be safe and free from dangers to health, but should also be as aesthetically attractive as possible. Absence of turbidity, color and disagreeable or detectable tastes and odors is important in water-supplies intended for domestic use.”

Fluoride levels should not be lower than 0.5 mg/l as this will contribute to dental decay in the population, especially in children. Nitrates, on the other hand, should not exceed 50 mg/l and 100 mg/l. If bacterial organisms of the coliform type are present, this means that the water has faecal contamination and therefore is not fit for human consumption. Moreover, the water should be free of any taste and smell. The table below presents the acceptable levels in drinking water for other chemical substances.

“World Health Organization (1958:29) “Chemicals affecting portability of water”

Total solids 500 mg/l 1500 mg/I

Colour 5 units 50 units

Turbidity 5 units 25 units

Taste Unobjectionable

Oduor Unobjectionable

Iron (Fe) 0.3 mg/l 1.0 mg/l

Manganese (Mn) 0.1 mg/l 0.5 mg/l

Copper (Cu) 1.0 mg/l l.5 mg/l

Zinc (Zn) 5.0 mg/l 15 mg/l

Calcium (Ca) 75 mg/l 200 mg/l

Magnesium (Mg) 50 mg/l 150 mg/l

Sulfate (SO) 200 mg/l 400 mg/l

Chloride (Cl) 200 mg/l 600 mg/l

pH range 7.0-8.5 ≤6.5 or ≥ 9.2

Magnesium + sodium sulfate 500 mg/l 1000 mg/l

Phenolic substances (as phenol) 0.001 mg/l 0.002 mg/l

Burke (2002:1) notes that the main aim of monitoring the quality of water is to ensure its clean and safe supply. Some of the variables to check in order to get an indication of water quality include temperature of the water, alkalinity and acidity, density, amount of salt, gas levels such as oxygen and nitrogen, chemical substances such as nitrate and phosphorous and micro-organisms such as protozoa, among others. One may therefore carry out the process from a physical, chemical or biological perspective or use all of these angles of analysis. However, this process also involves checking the hygiene levels of water bodies in use by many stakeholders and those that offer a habitat for animal and plant populations.

Since water is one of the resources in the natural environment, it is susceptible to effects from manufacturing plants that utilize natural resources. These include geothermal plants, quarries where mining takes place and the timber industry that makes use of wood from forests. Monitoring the quality of water therefore involves assessing the impact of such industries on water, water bodies and catchment areas. Another reason for monitoring the quality of water is to check whether a particular type of water mass meets the standards set for it. The standards depend on the use of the water body. These include for water for drinking purposes, leisure, fishing, habitat for wildlife, farming and industrial use.

She adds that there exist three main ways of monitoring the quality of water. Burke (2010:1) mentions “discrete, mechanical, and automated methods”. In the first instance, which is the old way of monitoring water quality, one measures a single aspect. This is done either in the field or in a laboratory. This method is tiring and time-consuming. At the same time, it is subject to the operator’s bias and judgment when collecting the samples as well as when doing the analysis in a laboratory. The second method involves leaving bottles in a water mass for some time to collect water then taking these to a laboratory. This method reduces the manual effort and time spent collecting samples of water. However, it is subject to bias from laboratory analyses and at the same time, leads to loss of time spent waiting for the bottles to collect water. The third method makes use of devices that will sense the aspect of water quality being tested and these in turn store the information. This method is fast and likely to yield more reliable results than the other two as it does not rely on the subjective judgment of the analyst in a laboratory setup.

In the monitoring of water quality, screening methods have become more common than other techniques. This is because they are fast and easy to use due to their advanced technology. Gonzalez, Greenwood, & Quevauviller (2009:16) note, “Screening methods are often chosen by field operators for rapid and simple measurement of water quality. They are also called alternative methods or emerging tools. There are different types of alternative method such as ready-to-use methods (test kit method), handheld devices (handheld instrument with generally no reagent needed), online sensors (generally in an industrial context) and methods for biological monitoring (such as bio markers, whole-organism tests).”

To improve the process of monitoring water quality, DEWA has integrated an automated system among its management programs. According to DEWA Company (2009:15), “7-Technologies has entered into agreement with our German system integrator, Cegelec, for the supply of an AQUIS real-time water management system to DEWA in the United Arab Emirates. The AQUIS platform supplied includes all the AQUIS modules: Hydraulic, Water Quality, Surge, Load Forecaster, Leak Detection, GIS and SCADA Interface. The real-time system will provide asset and process performance monitoring and give early warnings of potential operational problems. This will improve planning and design, serviceability, water quality and leakage reduction.”

For this topic, I choose the automated technique of measuring water quality because it is fast and yields more reliable results. This method makes use of devices capable of sensing the variables under consideration. Since the DEWA Company distributes water for human consumption, it has to ensure that it stores and distributes enough water for the population. DEWA Company (2009:3) “DEWA has a policy to maintain bulk storage of potable water equivalent to two days of system peak demand.” This implies that it has an extensive reservoir and distribution system, which is not possible to monitor manually on a regular basis.

Moreover, the stored water is susceptible to residue of chemical substances such as chlorine and this may affect the quality of water the firm distributes for human consumption. The company therefore requires continually monitoring of the quality of the stored water and the automated technique would be the most appropriate. The technology applicable here would be the online sensing devices that would read the chlorine levels in the tanks as well as the input and output pipes. To monitor water quality in the DEWA Company (2009:5), “analyzer stations consisting of transmitters and sensor assemblies for measuring pH, residual chlorine, conductivity and temperature may be installed at specified locations as per DEWA’s specifications”.

The quality of the water that DEWA produces is as follows:

DUBAI ELECTRICITY & WATER AUTHORITY

TRANSMISSION & DISTRIBUTION: WATER DIVISION

OPERATION DEPT. LABORATORY

TYPICAL RANGE OF COMPOSITION OF DEWA WATER ELECTRICAL CONDUCTIVITY

250-800

MICROMHOS/CM

pH

7.5-8.5

TOTAL DISSOLVED SOLIDS

125.0-400.0

Mg/l

CHLORIDE AS CI

<200.0

Mg/l

BICARBONATE AS HCO3

50.0-75.0

Mg/l

SULPHATE AS SO4

<20.0

Mg/l

NITRATE

<1.0

Mg/l

CALCIUM AS Ca

15.0-25.0

Mg/l

TOTAL HARDNESS AS CaCO3

50.0-120.0

Mg/l

MAGNESIUM AS Mg

2.0-20.0

Mg/l

SODIUM AS Na

<200.0

Mg/l

FLUORIDE AS F

NIL

TASTE, COLOUR AND ODOUR

UNOBJECTION-ABLE

COLIFORM BACTERIA

NIL

The above table incorporates variables of assessing quality of water from a chemical, physical and biological perspective. From the data, it appears that the DEWA Company produces relatively high quality water. This is because, according to the above table, the water is free from any taste, smell and has no color and is therefore transparent. In addition, it is free from contamination by coliform bacterial organisms, meaning the water has no faecal pollution.

However, there is no fluoride present in the water meaning that it is likely to cause dental problems in the consuming population. As the World Health Organization (1958:28-29) notes, “If the fluoride concentration in the drinking-water of a community is less than 0.5 mg/l, a high incidence of dental caries is likely to occur. To prevent the development of dental caries in children, a number of communal water-supplies are fluoridated to bring the fluorine concentration to 1.0 mg/l.”

Moreover, the water is safe for consumption because its nitrate levels do not exceed the World Health Organization directives of 50 mg/l and 100 mg/l. The water pH does not raise concerns since the levels of alkalinity and acidity of the water are within the accepted range. It is therefore possible that there are few land use activities in the areas from which the company sources its water. Consequently, fewer chemical substances such as fertilizers and pesticides wash off into the water sources. In addition, the amount of chloride is also on the lower end of the permissible range, which means that salinity of the water is low. However, the amount of dissolved matter is less than the permissible level therefore the water density is low, but on the other hand, this means that the salinity levels are low. The magnesium, calcium and sulphate contents are also lower than the acceptable minimum, which means that though the water lacks essential components, it has low salinity levels.

According to the above table, the water from the DEWA Company is relatively good for consumption because it does not contain toxic substances such as lead or cyanide. The presence of nitrates in the water that the firm supplies is likely to be due to the discharge of treated sewage water while that of sodium is due to the use of this compound to clear chlorine residue. On the other hand, the absence of fluoride in the water may be due to changes in climate in the areas where the company sources its water.

The high potential of the water to conduct electricity may be due to the presence of radioactive matter. This is also evident in the presence of hydrocarbons in the water. The salinity of the water is low meaning that there is a higher amount of freshwater than salty water entering into contact with the sources of the DEWA water. Since the amount of dissolved solids in the water is less than 1000mg/l, it appears then that the DEWA water is fresh. It appears that the water is soft because the levels of magnesium and calcium are low. Moreover, the amount of solids dissolved in the water is low indicating that the saline content is also low.

According to Statgraphics (2006:1), “An important technique used to determine how well a process meets a set of specification limits is called a process capability analysis. A capability analysis is based on a sample of data taken from a process and usually produces: an estimate of the DPMO (defects per million opportunities), one or more capability indices and an estimate of the Sigma Quality Level at which the process operates”. From the above table, it appears that the water quality management process at the DEWA Company is capable of meeting the needs of the population. In addition, it appears that the company is capable of providing good quality water for human consumption to its consumers.

The strengths of the system include its ability to lower the saline content and the amount of dissolved solids therefore producing water that is fresh. Furthermore, the water does not contain toxic substances such as cyanide, lead, among others, and this implies that it is fit for human consumption. Moreover, there is a balance between the water acid and alkaline levels as the pH is within the acceptable range. The nitrate levels are also within the acceptable range and therefore do not pose a threat to human health. In addition, the water is soft rather than hard due to reduction of magnesium and calcium elements. Another strong point is that the management system has preserved the water’s aesthetic quality since there is no odor, color and taste present.

Moreover, the water is free from faecal pollution as there is no contamination by bacterial organisms of the coliform nature. According to DEWA Company (2009:7), “DEWA’s water system consists of a transmission network where pipe diameters range from 550 mm to 1200 mm, and distribution network where pipe diameters range from 100 mm to 450 mm.” This means that the company is able to transmit and distribute large amounts of water at any given time due to the large capacity and volume of its transmission system.

On the other hand, the water production system has fewer defects than the strengths listed above. The defects include production of water with no fluoride element, which can lead to tooth decay. In addition, the electrical conductivity of the water is very high indicating the possibility of contamination with radioactive matter. However, the strengths of the system of water production outweigh its weaknesses. The indicators of the system’s capability to produce good quality water are the variables that the company uses to measure the quality of water. These include lack of taste, smell, color, coliform bacterial organisms that are indicative of faecal pollution, few nitrate, calcium and magnesium contents that are an indication of low salinity levels, normal alkaline and acidity levels, a low amount of dissolved solids and the absence of poisonous substances such as lead and cyanide. In conclusion, it appears then that the company is capable of producing good quality water for the consuming population. Consequently, we can also say that the management system of the DEWA Company in relation to the production and supply of water is one that is effective in terms of ensuring good quality water.