Friday 30 August 2013

THE FCT URBAN WATER SCHEME PLANT 1 & 2 PART 2

THE FCT URBAN WATER SCHEME PLANT 1 & 2
PART 2

Water Quality Standards
One of the most common legislative tools in water management is establishment of quality standards (i.e. attributes of the type of water that we wish to retain). Quality standards are, in effect, a regulatory tool that lists specific qualities associated with specific desired uses. To establish such standards, uses or values of the water resource are determined and then specific quality attributes are assigned to those uses. For example, a water body for use as a public water supply will have an associated list of attributes such as low turbidity or levels of heavy metals below some certain threshold. Consequently, qualify standards are specific to a given use and represent the maximum allowable level of pollution.
Quality standards are based on assimilative capacity of a water body (i.e., the ability of the resource to receive wastes or impacts and maintain its structure and function within the bounds of set standards). An ecosystem can assimilate or diffuse some impacts without exhibiting unacceptable characteristics. Logically, larger bodies of water can assimilate more than smaller
Streams fast-moving streams can assimilate more than slowing-moving ones. Because water treatment facilities are extremely expensive, an enormous emphasis has been placed on the natural assimilative capacity of waters throughout history (i.e. dilution is the solution to pollution). This concept is still the primary treatment philosophy in many developing countries. Identifying the uses for which a water resource will be managed is the first, and most important, step in managing water quality.
Quality standards are based on assimilative capacity of a water body (i.e., the ability of the resource to receive wastes or impacts and maintain its structure and function within the bounds
of set standards). An ecosystem can assimilate or diffuse some impacts without exhibiting unacceptable characteristics. Logically, larger bodies of water can assimilate more than smaller streams; fast-moving streams can assimilate more than slowing-moving ones. Because water treatment facilities are extremely expensive, an enormous emphasis has been placed on the natural assimilative capacity of waters throughout history (i.e. dilution is the solution to pollution). This concept is still the primary treatment philosophy in many developing countries. Identifying the uses for which a water resource will be managed is the first, and most important, step in managing water quality.
In Nigeria, as in most developing countries, water quality is generally deteriorating, especially
around urban areas. Population growth and industrial expansion are generally not managed by
appropriate standard, enforcement of infrastructures such as sewer systems and water treatment
plants is not done. Meybeck et al (1989) noted that only 10 out of 60 rapidly developing countries have established effective water quality laws, regulations, or enforcement of relevant
infrastructures. In addition, the fast pace of development and pollution creates nearly impossible
situations: the pollution that grew over a 100 year period in developed countries now occurs in
barely a generation in developing countries (Meybeck et al 1989). Consequently, few major
cities in the developing world have adequate sewage treatment facilities, and municipal potable
water supplies are often not disinfected. Nigeria is not an exception.
In lower Usuma dam, the quality control unit is divided into three sections Physiochemical, bacteriological and biological. They carry series of sample tests in the laboratory to determine the quality of water produced, by observing the UNO’s standard for production of water.
The Physiochemical section is responsible for carrying out quality control analysis on the physical and chemical properties of water while the bacteriological sections are charge with the bacteriological examination of the water. The biological monitoring unit is responsible for aquatic ecosystem of the reservoir and ecology of the catchment area as it affects the quality of raw water in the reservoir.
The quality control section is also responsible for performing experiments relating to the quantity of chemicals dosed into the water. The treated water must be checked to be in conformity with the World Health Organization (WHO) recommendations before distribution to the various storage tanks in the territory.
The quality controllers also monitor water even as it is distributed from the treated works and within the territory. From time to time the quality control staff visit individual houses and collect samples to analyses. The board looks at water always from the point of view of how clean it is, its effect on health, laundry etc.
                                             

Similar tests are carried out three times a day to ascertain the quality of the treated water. These results pass through many Officers for verification before finally handed over to the production unit whose sole responsibility is to enforce a change in the pumps. Similar tests are carried out to ascertain the value of Aluminum Silicate contained in the Alum, when new supply of Alum is delivered into the plant.

MAINTENANCE OF WATER TREATMENT FACILITIES
Maintenance of water treatment facilities in lower Usuma dam treatment plant is the sole responsibility of the Estate and facilities manager who is charged with helping to prolong the design life span of the facilities in the plant so as to protect public health and the environment of the community the dam is sited. The periodic maintenance of facilities is done quarterly this includes: washing the walls of Clarifiers, Aerators, chemical loading tanks and Filters. Those done every six months are washing the floor of the clarifiers, treated water tanks and those reservoirs around the various Area Councils in Abuja. Other works are the repairs of reported broken pipes, replacement of spare parts of pumps, Chlorinators and equipment.

FINANCING, CHEMICAL PURCHASE
The Federal Capital Territory water board is an agency of the Federal Capital Territory Administration and do receive monthly subvention or running cost to offset some of these responsibilities mentioned above. When the cost of a particular work is above the monthly subvention such as chemical purchase, replacement of faulty equipment and main trunk pipelines will need to go through the procurement procedures.

SUGGESTIONS FOR IMPROVEMENT
Suggestions to the improvement of maintenance of water treatment facilities, is to ensure that those entrusted with the responsibility of running the establishment should be prudent and sincere in managing the mega resource at their disposal. Also to promptly bring to the notice of the higher authorities on  any serious works which your subventions cannot cover and this should done on time as to avoid disruption of water to the populace.

CUSTOMER COMPLAINTS
The Federal capital territory has created consumer complaint offices in various area councils in FCT and a central office in the head Office to coordinate and settle any issues beyond the area offices.
Complains like not having regular water supply, water supplied was contaminated with some particles or color seen,  problem of billing system and complained that the billed does not reflect with the meter reading installed.
During one of the consumer-administration flora, where the minister of FCT was the guest, He explained that the shortage of water supply was as a result of the overwhelming influx of people into the FCT, thus creating an upsurge in the population of the territory. He observed that the only water treatment plant currently serving the territory is being over stretched.
And said for a comprehensive approach to the problem the Administration is doing everything humanly possible to ensure that Gurara dam is completed, so that there is enough water about 8 times of what is available at the lower Usuma dam for consumption by residents of the FCT. In addition the water treatment plant being constructed to treat the raw water from Gurara dam, has its essential components in place; the Chlorination Room, the Filtration, Rotors, Clarifiers are all in place, the only missing component is the water pipe to convey raw water from Gurara dam to the treatment plant that is at a 95% completion stage and there is the need to build more water treatment plants to increase the volume of water being supplied to residents.
The FCT Water Board has set up an interactive mechanism with its customers to tackle their problems and ensure effective service deliver through interactive sessions by buying air time in various radio stations and a bi-monthly Customers' fora, an avenue for customers to make their views known to the board for prompt action.
The board had introduced a customized billing system for easy payment, so that customers’ complaints would be addressed to avoid a recurrence.  The Chemical: Lime, Alum and Chlorine and including fuel for powering the plant in time power outage are procure through the award of contract by the FCT Administration.

WATER CHARGING
Traditionally, water services have been regarded as one of governments many responsibilities –it must be supplied regularly and free of charge. In some parts of the country, inhabitants still do not understand why they must be made to pay for this free gift from heaven. The development, distribution, and treatment of water include costs for design, initial investments, and operation and maintenance of the service. Putting a price to water is a reflection of water’s economic value and it affects water use efficiency, it is a key way to improve water allocation, discourage wastage, and improve conservation. However, the current practice whereby State Water Corporations charge fixed rates for services rendered only intermittently does not encourage consumers to pay. In most urban areas, there is scarcely a household that does not have, or nurse the ambition to have, an alternative source of domestic water supply by constructing a hand-dug well or a borehole. State Water Agencies should consider the introduction of water meters, particularly in urban centers, this simply act of measuring consumption can help people control the actual amount of water they use and/or waste, it is also a more accurate, equitable and just way for the Water Agencies to commensurately get paid for services rendered. Although FCT Water has installed water meters in most of the urban house as well as some other area council and it has gone further to installed a prepaid water meters in urban house, all these great strikes came with a lot of human and technical challenges that seems to be making non- sense of the effort.
 But now with much larger communities requiring service, the only way to ensure that everyone has access to this basic need is to ration it in some way. And perhaps the best way to utilize water to the best and most-valued uses is to put a price on water, and Construct appropriate tariff structures to meet different social, political and economic goals in different situations.
 The FCT Water Board has different price charge for highbrow areas of the Federal capital city (FCC) and other area such as satellite towns and commercial user. Thus using cost price analysis method the cost of N300.00 was obtained while the subsidies for these categories of places are: N120.00, N80.00, and N150.00 respectively.

SUGGESTIONS FOR IMPROVEMENT
In order to achieve the goal of providing a portable drinking water for the people of Federal capital of Abuja in an affordable rate and still maintaining the different tariffs listed above, the authority must cut down water wastages that are found during backwashing of filters by repairing as soon as possible the recovering pumps which are responsible for recycling this water are faulty. The corruption among the staff that go out on field to compromise their duties during the distributing of bills and disconnecting those consumers who are found to default in payment should be punished as this action tarnish the image of the organization, as so many cases were raised during one of the customer’ fora,
The authority should give special incentives like welfare packages to its staff to encourage and boost their morale, this will give them a sense of belonging and thereby reducing the corruptive tendencies that they engaged themselves in, as this will go a long way in  improving the revenue generation of the establishment.

INAUGURATION AND INSTALLATION OF TOTAL QUALITY MANAGEMENT SYSTEM
Total quality management (TQM) is a management system which has been attracting the attention of North American companies during the last decade.
This system is designed as an integrated, customer-focused approach to improve the quality of an organization’s processes, products and services. Despite the numerous attempts to incorporate TQM in organizations, relatively little is known about its effectiveness and optimal implementation strategies. Few systematic studies have been carried out to evaluate TQM empirically, also, little theory exists to guide TQM implementation. The overall purpose of the current article is to provide a better conceptual basis on which to incorporate TQM into organizations and to guide future research efforts. In doing so, a performance management system is described which is designed to be compatible with total quality implementation.

COMMUNITY-MANAGED SYSTEM: THE WATER USERS’ ASSOCIATION
OPTION
There are several options for water supply management, ranking from the agency managing it to the community owning and operating the system, with options in between. Trends are currently to give the community more responsibilities as an alternative to government management of water supply (Carter et al., 1999). A water user’s association is one of the community-based possibilities, characterized by the association being responsible for operation and maintenance financed through member’s fees and bills, access to water services is reserved for members only Cairncross, 1980). Cairncross et al. (1980) shows two advantages of this option: to potentially avoid factionalism and to facilitate fees collection as members get privileged towards non-members. They also point to the implicit exclusion of part of the population, mainly the poorest households unable to afford the prices.
The option of water kiosks where members come to buy water have already been implemented in other African countries and even in Kabong in Nigeria, most often it has been implanted in urban and peri-urban areas like those in satellite towns of Abuja

WATER QUALITY MONITORING
As there is for the moment neither national water-drinking quality standards nor guidelines in Nigeria (Ocholi, 2006) there is a need to find universal water quality standards values. The “Guidelines for drinking-water quality” proposed by the World Health Organizations set a complete list of parameter values which “ensures an aesthetically pleasing water and does not result in any significant risk to the health of the consumer” (WHO, 1985). These values are internationally recognized because health issue oriented; however it does not take into account the specific context of the country or area (WHO, 1985). In fact, concerning developing countries, these parameters need to be adjusted, considering the cost of treatment involved, cost and availability of water testing in the country.
Therefore, according to the WHO approach, the following criteria were going to be
assessed

 Water quantity
 Water quality
 Reliability of the water supply
 Convenience of water points
 Proportion of households using the facilities
 Volume of water used and for what purposes.
The last two criteria are not known as there are no figures in the organization, while the first two are known from the results obtained in the laboratory of Lower Usuma Dam Treatment Plant (LUDWTP) as seen in appendix E. In the case of the third point, the water is not enough to go round at a time so it is been rationed.

A snap-shot Semi-Structure Interview (SSI) of 26 community members was done to collect a) data on use of public taps from random people. In all community member interviews, level of wealth was determined by the type of house: thatch huts, zinc roof and fenced house in ascending level of wealth. The way of conducting interviews and asking question was adapted during the survey in order to be clearly understood by the population and to fit the local situation.


Saturday 10 August 2013

THE FCT URBAN WATER SCHEME PHASE 1 & 2 PART 1

THE FCT URBAN WATER SCHEME PHASE 1 & 2
PART 1
Introduction
Lower Usuma Dam
Lower Usuma dam is located at about the highest point in the Federal capital territory in the North western part of the territory and feed the treatment plant by gravity. Sited on a virgin location where human activities is minimal. Thereby ensuring non pollution of the environment and free from industrial impurity.
The dam is homogeneous earth fill with an upstream face of rock fill while the downstream is grassed with a grout out wall with vertical and horizontal fitters. The dam is provided with a pumping station in order to pump raw water from main dam reservoir to the water works in the event of extreme drought.  

The sources of the raw water come from three outlet: The two major rivers: River Usuma where it takes its name from, River Gidna and Gurara transfer outlet.
It is made up of two system of dams: the main and secondary saddle dam with a spillway in the rock in-between.
The characteristic of main dam:
Dam height- 49m
Dam crest length- 1300m
Dam crest width-        10m
Reservoir capacity- 107m3
Maximum width- 250m
Free board-      5m
Area at full supply level- 8.5KM

The saddle dam is located on the right of the right abutment of the main dam. The construction of the saddle dam was born out of the need to maintain a maximum supply level of 570m above sea level which correspond to maximum reservoir capacity of 107m3.
The saddle dam is an earth dam with a zoned laterate with impervious core.
Saddle dam characteristic:
Dam height-    25m
Dam crest width-        10m
Free board-      5m
Construction time 1980-1984
Designer/constractor- Spic- Batignolles Nig. Ltd (with Guff as original designer).
The dam is covered with gravel while the upstream slope has a rip-rap protection and the down-stream slope is protected with grass.

. The intake structure is a concrete, circular shape, has eight intake points at four different levels these convey raw to the treatment plant. It has height of 40m and diameter of 10m. The construction time for the dam was from 1980 to 1984 and the reservoir impoundment commenced on 1984, it was designed and constructed by Spie Batignolles Nigeria Ltd. With Guff as original designer.

PRECAUTION AT DAM SITE WITH DYKES/ EMBANKMENT
The instrumentation in the dam are instruments set on the embankment to protect the dam, these include pore pressure cells and piezometers.
Pore pressure cells
Pore pressure cells in saddle dam are based on the vibrating wire strain gauge principle, the changes in pore pressure acting on the diaphragm causes changes in the tension and frequency of vibration of a fine steel wire.
There are ten cells in all, two each located in profile 50, 95, 105, 175 and 245, and are located in the fill. The pore pressure obtained from these cells may use to establish the saturation line or the phreatic surface and the flow within and underneath the dam.
Piezometers
In dam piezometers are installed in a row parallel to the dam axis down of the in 50, 100, 150, 200, 250, 300 and 340, running from left to right abutment. Water levels in the piezometers are measured to obtain the ground water level and raising of pore water in the embankment.

GENERAL PLANT STRUCTURE
Raw Water Inlet Structure
The raw water inlet structure is the place where the treatment of the incoming raw water starts. The raw water is obtained from a dam 2km away from the treatment plant. It is supplied via a pipeline from the dam to the inlet structure, with the flow rate averaging about 5000 m3/hr.  Raw water inlet Structure is divided into three sections, namely the aeration chamber, distribution chamber and dosing chamber. 

Raw water inlet structure
The Aeration chamber                                          
The aeration chamber is that section of the raw water inlet structure, which consists of a series of four weirs which forces the raw water to flow downwards, upwards and back down again in a turbulating manner. This is the first step in the treatment process and is aimed at removing the foul odor/smell that comes along  with the raw water in the form of H2S (Hydrogen sulphide), as well as oxiding the ions present in the raw water, with Iron (II) oxide (Fe2+) being the most notable. It also improves the dissolved oxygen content of the raw water. 
Aeration Chamber


The Distribution chamber 
This chamber ensures the even distribution of the aeration water into the two sections of the dosing chamber that leads to the different clarifiers (settling tanks).

The Dosing chamber 
 After distribution, the aerated water flows to the dosing chamber (which is the third and last section of the raw water inlet structure). This is where the treatment with chemicals begins. Here Aluminum sulphate (Al2 (SO4)3), chlorine (Cl2) and calcium hydroxide (Ca (OH)2) are added to the aerated water. 
Aluminum sulphide (Alum for short), is added to cause coagulation of the minute particles that cannot be seen with the naked eyes, as well as the visible dirt particles. These particles are positively charged and therefore repel each other. Thus, the introduction of a negatively charged substance Alum is used to bring these particles together and make them more visible and heavier, so that they can be dealt with easily.          Chlorine is added to the aerated water in the form of chlorinated water. That is, gaseous chlorine is dissolved in water and this form chlorinated water. Chlorine is used as a disinfectant in water treatment i.e. it destroys the microbes present in water; it serves as a coagulant to extent. Addition of Alum and chlorine to the aerated water reduces the PH of the water thus makes the aerated water acidic. Powdered Lime (CaCO3) is dissolved in water, to form hydrated lime (Ca(OH)2) and is used to bring PH of the aerated water to more suitable level for further treatment.
These three chemicals will react with the aerated water in the dosing chamber, which is characterized by turbulent flow, for thought mixing. The amount of Alum and Lime to be added to the aerated water is determined by a jar (flocculation) test, carried out in a laboratory.

The Pulsator Clarifier (Settling Tank)
After the aerated water has been treated with the chemicals mentioned above, it flows through an underground pipe, to the clarifier, where further treatment takes place. The clarifier is basically a large settling tank, where the clog formed as a result of coagulation, come together to form floccs (which are bigger particles) and settle. Floccs are bigger and more visible particles, as compare to clogs and are formed by the process the process known as flocculation. In the clarifier, the biggest particles formed settle to the bottom of the tank, while the clear water remains at the top of the tank. In between, there are several settling zones/layers, which consist of flocc particles of different sizes. The floccs, which settle to the bottom of the tank form what is known as Sludge. It is essential that the sludge blanket (sludge covering the base of settling tank) be present during flocculation. This because the sludge blanket attracts other flocc particles to its self and thus improves the flocc settling rate i.e. improves flocculation.

Clarifier showing troughs
From time to time, the level of the sludge blanket increases and needs to be reduced. The operation by which excess sludge is removed from the clarifier is known as de-sludging and takes place in the de-sludging chamber.

The Pulsator
If the sludge is left undisturbed, it will solidify to form sludge cakes, which breaks up, floats to the top of the clarifier and makes the clarifier appears dirty. It will also reduce flocculation efficiency, as the sludge cakes do not attract floccs to themselves. Even when they do, they tend to reverse the process of flocculation, as the floccs will be rising up instead of settling downwards. The pulsator is thus used to disturb the sludge regularly and keeps it in molten state.
The pulsator is a suction device that works on the principle of suction. It consists of a flat-bottomed tank with a series of perforated pipes uniformly distributed over the entire bottom of the clarifier.
The principle consists of removing the air by suction, with aid of fans from the vacuum chamber. As a result, the water level rises gradually inside vacuum chamber. When it reaches a level between 0-6 and 1.0m above the clarifier water level, a contact sudden opens an air inlet valve. Atmospheric pressure is therefore immediately supplied to the water stored in the vacuum chamber and the water flows into the distribution pipes at high speed.

The Filter
After settling the clarified water flows into the filters, where filtration takes place. Filtration in this case, is the movement of water through a sand bed (permeable medium), which allows the clear water (filtrate) to pass through the permeable medium and retain the dirt or residual particles that did not settle in the clarifier, as well as other minute substances, leaves etc from the surroundings, as the residue. The sand bed consists of different sizes of sand particles, from fine to coarse particles. The filter (clear water in this case) is collected by a structure known as siphons, from which it flows to the treated tank.

Backwashing
From time to time, as the sand bed continues to filter the clarified water, the residue will accumulate to an extent that it will block the surface of the sand bad and thus filtration can no longer take place. This process is known as filter clogging. The operation used to correct this problem is known as back washing. It involves the addition of air under pressure, from beneath the sand bed, through the nozzles as well as water for rising.
The air supplied causes the sand particles to rub against each other, thereby removing the dirt attached to them, while the water supplied, and
rinses the dirt off. The whole process is control on a back washing desk- a device with a number of buttons and switches to control the flow of water and air into and out of the filer bed, during back washing.
The water recovered during back washing is collected in a recovery tank. The clearer part of the water is recycled to the aeration chamber at the raw water inlet structure, while the very dirty part of the water is discharged as sludge waste.


Back washing of a Filter in progress
The Treated water tank 
The treated water tank is divided into two sections, the tank the storage tank:                          
The Contact tank
This section receives the filtered water from the siphon and chlorine in the form of chlorinated water, is added to finally disinfect the water. This tank consists of baffles that cause the filtered water to meander its way through the tank. This is aimed at holding the filtered water for a period of 20-30 minutes for proper chlorine contact because, it is expected that no living microorganism can survive after contact with chlorine within that time range. There is always some residual chlorine in the treated water to make up for the organisms that will be encountered by the treated water on its journey to the consumers, along the pipe network.

The store tank 
After 20-30 minutes, the treated water flows into the sludge tank, where it is stored and lime is added for PH correction. The water is distributed under gravity to area of low altitude and by pumps to higher altitude or distant locations.

The Lime Saturator
Lime produces a milky color when dissolved in water, which tends to give the impression that the water is impure/dirt even if it is not. Lime is added to water at the treated water tank, which is the final treatment stage of water purification. If the lime is just dissolved in water and used like that for treatment, it will make the treated water colorful. To prevent this, the lime needs to be dissolved in water to a micro level, so that its color is not visible when used for treatment. The lime saturator is equipment used to achieve this.


The Alum tank
There are two alum tanks of 52 m3 capacity each. The tanks are used to dissolve the solid Aluminum sulphate (Al2(SO2)), as this is the form in which the alum is dosed. About 80 bags of solid Aluminum sulphate is dissolved in water treatment per two days each weighing 50 kg. Only one of the tanks is used at a time.

The tank has gauze on which the Alum is packed. The tank is then flooded with water to dissolve the alum. An air blower, to cause agitation is applied, this makes the solid alum pieces to rub against each other, wear themselves out and thus enhance dissolution.

The Lime tank
The lime tank is a close tank with a hopper on top, through which the powered lime CaCO3 is fed. The tank is the flooded with water, to dissolve the CaCO3 and convert it to Ca(OH)2, as this is the form in which is used in water treatment.

CaCO3(s) + H2O (l)                     Ca(OH)2(aq) + CO2(g)

CONSTRAINTS/CHALLENGES
Inadequate Funding
The Federal Capital Territory Water board was created specifically among other things to control, manage, install, and maintain all water works and service vested on it by the Minister of Federal Capital Territory. Therefore all funds generated from the sale of water go to the government purse. Running cost is given out monthly to carryout minor maintenance works. In cases where the replacement of broken or faulty parts, pumps and other plant facilities excess the monthly subventions, requests will need to go through procurement procedures which take more time, during this period the quality and quantities of water may be compromised.            

The summary of the entire water treatment process is shown below.