World Water Day: National policy on sustainable use of wastewater urged

Pakistan has no national policy on sustainable use of wastewater in Pakistan. A negligible portion ie 8% of wastewater in Pakistan is treated through sedimentation ponds to a primary level only but most of the treatment plants are not functional, therefore, the figure can be estimated around 1%. There is no existing concept of treatment at secondary and tertiary level.
This is according to the paper written by Vice President Pakistan Engineering Congress (PEC) Dr Izhar-ul-Haq in connection with World Water Day. The problem of industrial water pollution has remained uncontrolled because there have been little or no incentives for industry to treat their effluents. In villages the wastewater is disposed of by drains to open ponds or soakage pits resulting in unhygienic conditions. The municipal open drain water disposal also leads to health & hygiene problems in major urban centers. Irrigation brackish water is disposed of through LBOD & RBOD.
In his paper Dr Izhar suggested that there is a need to increase national level awareness and commitments to solve badly neglected water pollution by increasing waste water treatment, restoring polluted water bodies and address pollution prevention at its source in all forms. He also suggested that treatment of waste water would improve environment and health of the people. Once treated adequately, used water needs to be recognised as a valuable source. He called for encouraging the use of treated water especially where it can mitigate the water scarcity. He also called for increasing support for water and sanitation investments, particularly the mobilisation of local capital.
The recovery and reuse of materials removed from used water (such as energy and nutrients should be encouraged along with appropriate legislation adopted to encourage this form of circular economy. It should be compulsory for all the housing societies to practice rainwater harvesting and grey water recycling. WASA, Municipal Corporations, Cantonment Boards should treat its sewerage before throwing into river and also implement grey water recycling and its reuse where applicable.
According to the paper Pakistan was once water surplus country ie per capita surface water availability in 1951 was 5260 cubic meter / annum. This has gone down to below 1000 m3 in 2017 which is a state of water stress. The existing insufficient water storage capacity and gap between demand and supply is further aggravating the situation. Precipitation in Pakistan is temporally and spatially variable and unpredictable.
The average annual rainfall is about 240 mm. On the whole more than half the country receives less than 200 mm of annual rainfall. It is estimated that almost 9.9 million acres of the area is rain-fed. The direct rainfall contributes less than 15% of the water supplied to crops. River flows in Pakistan are seasonal with 82% occurring in Kharif and 18% occurring in Rabi season.
The Paper pointed out that major driving forces that threaten future sustainable water availability in Pakistan include; droughts, climate change, low water use efficiency and untreated disposal of wastewater. To cope with this situation, we need water storage / water retention facilities on war footing. Other sustainable water management measures include; water conservation, efficient use of water, rainwater harvesting and grey water treatment.
The Paper also pointed out that Pakistan is already at the threshold of water crises. We need to adopt innovative techniques to take stock of this situation. At present, major portion of the runoff is wasted due to one reason or the other. The indigenized rainwater harvesting techniques can conserve this runoff for future use.
According to the paper the quantity of wastewater produced in Pakistan is 962,335 million gallons, including 674,009 million gallons from municipal and 288,326 million gallons from industrial use. "The total wastewater discharged to the rivers is 392,511 million gallons, which includes 316,740 million gallons of municipal and 75,771 million gallons of industrial effluents. If we look at percentage composition of various contributing sectors; then 73% wastewater is of residential origin, 16% is contributed by agriculture sector, while 6% & 5% is respectively shared by the industrial and commercial sectors.
Presently, Pakistan stores only 10% of its average annual flows against 40% world average. Our carryover storage is only 30 days of average use against 120 days of India 600 days of Australia and 900 days of USA. This underscores the importance of water storage", The Paper said.
The Paper also said by 2050 the world urban population is expected to nearly double. This poses massive sustainability challenges in terms of infrastructure, basic services, food security, health, education, jobs, water, and sanitation systems. According to the Paper potable surface water supplied to Karachi city having population of more than 20 million is of the order 650 million gallon per day from Indus River and Kinjhar Lake, but requirement of the city is 1100 MGD according to WHO standard, 54 gallons/capita/day. That means Karachi gets almost 50% of its requirement. At-least one third of it is lost during transmission and at supply end. After the consumptive use, about 60% of the water goes to the sewerage system. Sewerage system built thirty years back in certain parts of the city is inadequate and also not operative.