| September 14, 2005 | Wednesday | Sha'aban 9, 1426 |
Measures for controlling water pollution
ACCORDING to a news item published in Dawn on Sept 8, a high-level meeting was held to discuss measures for controlling water pollution in Karachi. While the decisions taken were interesting and helpful, the measure specifically related to water pollution prevention was placement of underground water pipelines over ground. While this measure has its drawbacks (traffic obstructions, hindrances in pedestrian movement, susceptibility to vandalism of the pipes, occupation of usable roadside space), there are a host of other water pollution control aspects that need to be considered.
AMERICAN security expert Dr Rodney Jones, who heads Policy Architects International, based in Virginia, USA, says that in a general sense Pakistan’s missile programme seems designed to present an image of deterrence because the missiles command a range is not within the reach of aircraft.
Dr Jones, who was on a lecture tour for the Area Study Centre for Europe, University of Karachi, pointed out that Pakistan’s only logical opponent was India, and Pakistani missiles could apparently reach most parts of India, though not in large numbers. In that sense it is understandable that Pakistan keeps information secret as far as numbers are concerned together with their likely location and targets.
He was also of the view that if and when Pakistan got US F- 16s, it would further augment its capability.
Dr Jones was born in Missouri, India, where his parents were missionaries. His conversation with Dawn ranged over a wide range of issues.
Asked whether Sharon would accept a Palestinian state with its capital in Jerusalem. He said: “I think he can. He has no other choice. There is no way that Israel can live in peace if it is in charge of all the holy sites in Jerusalem.” Dr Jones pointed out that the US had never supported Israeli control over all of Jerusalem. But they had been shifting their stance since the Bush government came. There were people in his administration that would change the facts on the ground. He believes that the Muslims should have looked for a “sensible deal” much earlier. “It does not mean that Israel has done the right things but Intifida only exacerbates the problem for the US.” At the same time, he says, “it does not mean Sharon cannot negotiate. He was one who supported withdrawal from Lebanon and ordered a pullout from Gaza.”
Dr Jones believes that Pakistan’s initiatives with Israel showed that its potential as a regional power had to be respected. The present emphasis on ‘enlightened moderation’ is basically a commitment to conduct a kind of discussion in the Islamic world. It means to allow some sort of essence of Islam to be there but to disconnect it from violence and to end the notion that injustice automatically translates into violence and war.
Islamabad’s overtures would not stop Tel Aviv’s military ties with India and that must be recognized by policy-makers here, Dr Jones said. The American scholar was of the view that whatever arms Israel was selling to India were offensive in nature. In this context he mentioned the Falcon early warning system. But what Israel was doing with India might not be against Pakistan.
He said India was the biggest country besides the western countries to be supportive of Israel. It was a big market. India was watchful and took the initiative after the Cold War, but only when it was sure that the Arabs could not ignore Israel any longer.
Pakistan, he said, could benefit from Israel in the banking, IT and energy sectors and have more influence in the UN that could be transformed into other areas with a multiplier effect on issues like Kashmir.
Dr Jones believes that Iran has gained a certain level of expertise in nuclear energy, relevant for a nuclear weapons programme. His guess was that probably a small quantity of nuclear weapons grade uranium had been produced. Although the US was not likely to opt for military action against Iran on the nuclear issue, that should not mean that it would not. Nothing was off the board. But this time, he said, the Americans would not attack to occupy, as they did in the case of Iraq. They may attack Iran not to occupy it but to destroy its infrastructure.
Asked whether Israel could have any role in any future action against Iran, Dr Jones held that any action by Israel only exacerbated terrorist threats against the US. A major change in the situation would be when the Israelis had submarines loaded with missiles operating in the Arabian Sea.—Shamim-ur-Rahman
Due to the persistent water shortage coupled with the supply of water to a particular locality for a few hours in a day, heavy water wastage habits and relatively low water pressure in the pipelines, almost all the households in Karachi use suction pumps. Placement of new water pipes may not cause any problem, during its first year of operation. Over the years, the worn-out pipes would be vulnerable to negative pressure in the water pipelines, created by the suction pumps. Negative pressure in pipes will force surrounding contaminated water into the pipe, through weaker points. With waste water overflowing from manholes, which is a common occurrence in Karachi, water contamination would still occur.
The sensible measure, in this case, would be provision of drinking water 24 hours a day with adequate pressure. This will prevent use of suction pumps and consequently incidents of contamination. In addition, the leaks in pipes should be repaired and, the percentage of unaccounted water, which is presently 30 per cent (McIntosh, A.C. and Yniguez, C.E. (eds), 1997, Second Water Utilities Data Book, Asian and Pacific Region, Asian Development Bank, Manila), should be brought down to the reasonable level of five per cent.
In Karachi, a large number of the households boil water for drinking. This is indicative of unwholesome quality of water supplied by the KWSB. It is not proper to blame water distribution system for every incident of contamination. Water treatment plants are equally responsible. For example, during rainy season, the turbidity of the treated water increases far beyond the permissible level of 5 NTU (nephelometric turbidity units).
There are frequent complaints of inadequate disinfection of water supplied in the city. This is again a water treatment plant-specific problem. Water disinfection is practised for destroying or inactivating disease-producing organisms. It does not imply complete destruction of all living organisms, which is, sterilization. Disinfection has played a major role in protecting public health through the reduction of waterborne diseases for which chlorine is typically used.
Chlorine has also its drawback. While it is very effective against bacteria and viruses, it is relatively ineffective against pathogenic protozoa, such as Cryptosporidium and Giardia. Chlorine interacts with natural organic matter in water to produce trihalomethanes (chloroform, bromoform, dibromochloromethane, and bromodichloromethane), haloacetic acids and bromate which are carcinogenic. Environmental engineers suggest use chlorine dioxide, chloramines and ozone as alternative disinfectants. Finished water should first be tested for the presence of trihalomethanes, before changing the disinfectant.
To overcome the frequent complaints of poor quality of water produced by the treatment plants, it is suggested that an independent body may be entrusted with the task of monitoring the quality of treated water. It is not proper to allow KWSB to act as a policeman and, be policed at the same time.
Water treatment aspect is not that simple as it used to be five decades back. The raw water source, in the yesteryears, had simple bacterial contamination. Now, the raw water source (Indus river, in the present case), is subjected to agrochemical pollution, industrial pollution, thermal pollution and even radiological pollution. Good old water treatment plants, based on rapid-sand filtration system, had treatment units like flocculation, coagulation, sedimentation, filtration and disinfection. The treatment system was adequate for removal of turbidity and fecal contamination.
The agrochemical pollution, in Indus River, increases the likelihood of presence of nitrates and DDT in the Karachi’s drinking-water. Boiling concentrates these constituents. These parameters, together with fluoride, arsenic and heavy metals, which have serious health consequences, have never been checked in the Karachi’s drinking-water. Convention water treatment plants do not remove these constituents. Future water treatment plants, which the KWSB plans to install, must have tertiary treatment units for removal of these contaminants. For example, granular activated carbon adsorption system removes most pesticides; activated alumina removes fluoride and; arsenic is removed by resins and alumina.
Proper operation of water treatment plant includes regular monitoring of raw water and treated water quality. Most water impurities are in dissolved form and, cannot be seen by naked eye. Proper record of influent and effluent water quality should be maintained. All tests must be conducted in accordance with the procedures laid down in the Standard Methods for the Examination of Water and Wastewater — a joint publication of American Public Health Association, American Water Works Association and, Water Pollution Control Federation.
Lyari and Malir rivers in Karachi are subjected to untreated municipal and industrial discharges. These in turn cause marine pollution. Studies indicate high levels of heavy metals in aquatic life. KWSB must control wastewater discharges from industries.
In 1960s, the then KDA constructed trickling filters wastewater treatment plants in SITE and Mahmoodabad areas. These were very reliable, sophisticated and efficient plants and, produced high quality effluent (biochemical oxygen demand) and suspended solids (less than 30 mg/l - milligrams per litre). In 1982, KDA constructed another simple, low-cost and easy-to-operate plant, based on extended aeration system in North Karachi. Called aerated lagoons wastewater treatment plant, and designed by a local environmental engineer, the plant had the capacity to withstand shock loadings, volumetric, organic and inorganic and, produced the designed-quality effluent (BOD and SS less than 50 mg/l). The plant was appreciated by foreign experts. KWSB degraded these robust wastewater treatment plants and introduced their own insensible an aerobic ponds system in Mauripur. The net result is the high-level of pollution in Lyari and Malir rivers as well as in the sea.
The engineers of the water treatment plants should consult (a) Water Treatment Plant Design, a joint publication of American Society of Civil Engineers, American Water Works Association and, Conference of State Sanitary Engineers; (b) Water Quality & Treatment, by American Water Works Association; (c) Principles of Water Quality Management, by W. Wesley Eckenfelder, Jr. and; (d) Water & Wastewater Engineering, Vols. I & II, by G.M. Fair, J.C. Geyer and D.A. Okun, when they face any problem in water treatment and, for maintaining acceptable water quality.
These publications are as authoritative in, the field of water engineering, as Metcalf & Eddy’s book is, on Wastewater Engineering.
Water pollution control in Karachi is a broad-based issue with wide-ranging components requiring a sensible integrated approach. It is not impossible to control water pollution in Karachi. All it takes is the political will and, well-qualified, experienced and trained environmental engineers, to undertake the task.