Karachi is presently facing a water shortage of around 100 million gallons per day (MGD) as against its total water requirements of around 600 MGD. Efforts are afoot to enhance water supply from existing sources.
In addition, possibilities are being explored to increase supply of potable water through seawater desalination.
Desalination plants are being planned by the Karachi Port Trust (KPT), the Defence Housing Authority (DHA) and the Karachi Water and Sewerage Board (KWSB). Status of these projects are presented below:
A. The Federal Minister for Communications was quoted as saying that the KPT is conducting its own feasibility studies of two desalination plants to be constructed. One desalination plant would provide water to the people of Manora and Bhit Island, the second plant would be for Karachi city.
B. A contract has recently been signed at Karachi between the DHA Cogen Limited and Siemens A.G. for establishing a combined cycle power plant for electricity and seawater desalination to be installed at DHA Phase VIII.
Details of the project have been forwarded to the ministry for final approval. The project would have an installed capacity of around 94 MW and the electricity generated would be distributed through the KESC network.
The desalination plant would provide 3 MGD potable water by converting seawater into drinkable water, which would be distributed through Clifton Cantonment Board at a reasonable price.
C. KWSB has plans to build a seawater desalination plants of large capacity, at 450 MGD. A feasibility report for it to be started. The federal government has approved an amount of Rs 23 million for it and has already released Rs 3 million as the first instalment.
DHA, KPT and KWSB are planning to install seawater desalination plants of 3 MGD, 25 MGD and 450 MGD capacity respectively. Desalination technology is relatively new to facilitate the feasibility studies.
THE FOLLOWING SUGGESTIONS ARE OFFERED:
1. One can learn from the desalination plants in operation in the country:
(i) The Hubco power plant at Hub Chowki, Balochistan has in operation a desalination plant to meet water requirements for power generation as well as for the housing colony. Drinking water is also provided to the villages in the vicinity;
(ii) The Chinese Company building the port at Gwadar has already installed a seawater desalination plant to meet potable water requirements;
(iii) A desalination plant has been installed in Cholistan at Derawar Fort, about 70 kilometers from Bahawalpur, for treatment of brackish water, to make it fit for human consumption.
This plant was installed by the Cholistan Development Authority (CDA) in September 2003, at a cost of over Rs 0.70 million in six months. It has the capacity to treat 3,000 gallons of water within eight hours at nominal operational cost.
The plant could serve as a pilot desalination plant for duplication in cities which have brackish ground water.
2. The developed countries might be approached for details about cost-effective desalination technologies. China had offered to Pakistan a special package that incorporated low-cost desalination technology developed by its Tianjin Institute of Seawater Desalination.
The technology was reasonable compared to other technologies, reducing the production cost of one ton of potable water produced from seawater from 85 cents to 60 cents.
There might be other countries offering similar or better technologies for our needs.
3. KPT is already working on the preparation of a seawater desalination plant for Karachi while KWSB might start work now on receipt of the government's first instalment.
THE FOLLOWING POINTS BE KEPT IN VIEW FOR FEASIBILITY STUDY:
A. The feasibility report shall have better credibility if the consultants are reputed for their technical competence and quality of reports.
The Terms of Reference (TOR) including the outline of the feasibility report must be carefully analysed to cover all requisite areas for investigation.
B. Capital costs including the financing and preproduction cost is must be reviewed carefully.
The feasibility report must have details of tariff determination including detailed assumptions for all inputs and outputs.
The level of tariff would determine the profitability of the proposed company and whether it would be profitable for water utilities to switch over to the desalinated water supply from existing sources. In many cases, tariff can make or break the project.
C. The feasibility report should also include details about other desalination plants of similar capacity based on the same technology and already operating in other parts of the world.
Comparative data on capital cost and the cost of one million gallons desalinated water so produced may also be provided.
The stakeholders may not opt for a technology based on which there are no existing successful projects in operation.
D. Almost all areas of Karachi including areas under DHA administration have ground water that is brackish and could be desalinated, perhaps more cheaply than the seawater.
It needs to be confirmed if the selected technology would be suitable for desalination of brackish water and whether the desalinated water so produced would cost and quality-wise, be comparable with the desalinated water produced from seawater.
E. Environmental aspects of the desalination project, including the power generation plant must be fully assessed.
4. KPT, DHA and KWSB must have teams of experts to evaluate various aspects of the feasibility report.
The project feasibility, would need to be examined within a short time of the submission of the report.
A time schedule for the preparation of the feasibility report, government approval for the project parameters and for the implementation of the project be properly provided.
5. KPT, DHA and KWSB would all benefit if there was a close working relationship in the preparation and scrutiny of the feasibility studies as well as in the implementation of the desalination plants finally agreed upon.
The DHA and KPT would be assuming a new role of the bulk seller of desalinated water to the KWSB.
The tariff at which the water would be sold to the utility/bulk consumers would be of crucial importance, with potential for disagreement. One must sort out difficult issues earlier on so that after implementation, the operation of the projects is smooth and profitable.
The final tariff to be borne by the people of Karachi should also be reasonable, not exceeding the existing rates.
To foreclose the possibly of disagreements on the water tariff, the government should appoint a regulatory authority to determine the bulk tariff for the desalinated water.
6. Large quantity of water is lost in the distribution. The need for fresh capacity can be reduced to the extent wastage of water is controlled with better water management.
7. The shortage of drinking water must be tackled at a national level. Different water authorities must adopt a proactive approach and approach the provincial and federal governments to ensure adequate clean water for drinking.
Details about suitability of technologies for water treatment plants or seawater/brackish water desalination plants and could be shared among water authorities of different cities and regions.
Through collective research is possible to adapt the technologies to our conditions.