Water is polluted when it contains materials that make it unsuitable for a given use The story so far:Fresh water is fundamental to the survival of humans and most other land-based life forms. Ninety seven per cent of the earth's water is the salt water of oceans and seas. Most of the remaining 3 per cent is in polar ice caps, glaciers, the atmosphere or underground and hard to reach. Only 0.4 per cent is available for use. This water supply is maintained by water evaporating from oceans and lakes and then falling to the earth as rain in a process called the 'water cycle'.However, growing population, increased economic activity and industrialisation has resulted in an increased demand for fresh water. In addition, rapid urbanisation is changing patterns of consumption. This has caused a severe misuse of water resources. Discharging untreated sewage and chemical wastes directly into rivers, lakes and drains has become a traditional habit. Water bodies can no longer cope with the increasing pollution load. In Pakistan, water is mainly used for industrial, agricultural and domestic purposes.
The following table shows its percentage consumption for every use.Purpose PercentageAgriculture 69%Industry 23%Domestic uses 8%Since most water is being used by the agricultural sector, irrigation can cause waterlogging and salinity. This happens when the water table rises close to the surface of the soil. If plants do not use this water, it evaporates, leaving salts behind. Even in uncultivated, barren lands, a water table within 2 meters of the surface can cause salinity in the soil. If irrigation water containing high levels of contaminants evaporates, it can result in damage to the soil.The Punjab province draws its major share of drinking water from the natural ground water aquifer. Groundwater becomes contaminated when chemicals from surface water seep into soil and come in contact with the flowing groundwater. The movement of groundwater is through open spaces in soil and rock layers, which is usually very slow, indicating a very low dilution of contaminants. According to WHO, groundwater of Lahore up to 700-ft deep has been seriously contaminated and should not be used for human consumption. In 1989, pollution was found to a depth of 300-ft, and to 500-ft in 1992. Sources of surface and ground water pollution
• Municipal SewageMunicipal sewage is a major source of pollution. About 2 million wet tonnes of human excreta are annually produced in the urban sector of which around 50% go into water bodies to pollute them. National Conservation Strategy (NCS) states that almost 40% of deaths are related to water borne diseases. Domestic wastewater collects on the streets and in low-lying areas. The situation is further aggravated by the addition of untreated wastes from small-scale industries. In Pakistan, drinking water supply lines and open sewage drains in the streets are laid side by side. As a result, water is frequently contaminated when pipes erode. Most main sewers are between 30-50ft below ground level and are made of 10ft cement sections linked without proper safety seals. Poor connections combined with deteriorating low quality sewer pipes cause a lot of leakage. This outflow from sewer mixes with the water table and the contamination is carried to deeper levels. Hence the ground water which is considered safe becomes adulterated with everything from PCBs, lead, cyanides, mercury, solvents, hydrocarbon compounds, hospital and pharmaceutical industry waste.Ravi teems with toxic industrial effluent and untreated domestic sewage as soon as it enters Pakistan. This has made it literally a large open sewer.
• IndustriesIndustrial wastewater contains toxic chemicals. It is alarming that most industries have been started without proper planning and waste treatment plants. They just dispose of untreated toxic waste into nearby drains, canals or rivers. Lahore, Faisalabad, Karachi, Sialkot contribute major pollution loads into their water bodies. According to an EPD source, 9000 million gallons of wastewater having 20,000 tons of BOD5 loading are daily discharged into water bodies from the industrial sector. [Proceedings of International Symposium by CEWR in 1993, Paper by M.A. Saleemi]. Automobile service stations are another major contributor to surface water pollution. Untreated oil, grease and dirt find its way into nearby canals and rivers where it damages the ecosystem.
• Landfills & LeachingLeaching is the process where chemicals from a material dissolve into water while it is being filtered through that material. The resulting mixture is called leachate consisting of residues from decomposed organic matter and metals. Major contributors to leachate are municipal solid waste, hospital waste, chemical fertilisers, pesticides, stagnant ponds, toxic industrial waste, and sewage. Rusting cans, discarded batteries and appliances, paints, pesticides, cleaning fluids, newspaper inks, and other chemicals may also add to the toxic mixture of leachate.• AgricultureExcessive and uncontrolled use of chemical fertilisers and pesticides promotes contaminated agricultural run off. This not only pollutes the surface drains but the water trickling down to lower layers of soil causes a severe contamination of the natural aquifer. Over abstraction of groundwater prompts recharge from the surface water drains, which themselves are severely contaminated.
• Water pollution and humansThe WHO reports that 25-30% of all hospital admissions are connected to water borne bacterial and parasitic conditions, with 60% of infant deaths caused by water infections.The long-term effects on human health of pesticides and other pollutants include colon and bladder cancer, miscarriage, birth defects, deformation of bones, and sterility. Contamination of fresh water with radionuclides, which can result from mining, testing, disposal and manufacturing of radioactive material, as well as transportation accidents, has led to increased incidences of cancer, developmental abnormalities and death.Cesspools of stagnant dirty water, both in rural and urban areas, account for a large number of deaths caused by potentially fatal diseases like cholera, malaria, dysentery and typhoid.Nitrate concentration in water above 45mg/l makes it unfit for drinking by infants. The nitrates are reduced in body to nitrites and cause a serious blood condition called the "Blue Baby Syndrome". Higher concentrations of nitrate causes gastric cancer.Untreated and highly toxic industrial sewage is also used for irrigation near major cities. This can contaminate crops and consequently affect consumers.
• Water pollution and the environmentKarachi'suntreated wastewater from domestic sewage and industrial estates is discharged into the Layari and Malir rivers, which fall into the Arabian Sea. This waste has begun to pose a serious threat to the marine environment, as the channel water is contaminated not only with bacteria but also with toxic chemicals.Water pollution also extends a savage threat to wildlife of Pakistan. Animals drink water out of polluted water bodies, ailing ponds, rivers and streams. This sickens the animals and some may even die. Oil spills kill thousands of fish in oceans. Extreme pollution of river Ravi has destroyed the once existing 42 species of fish and the bird life around the river has migrated to other areas. Survival of small invertebrates, micro fauna and flora is also threatened.What can be done?
• Identify industrial units that are the biggest polluters of river water. If National Environmental Quality Standards (NEQS) regarding wastewater were strictly enforced, these industries would have to reduce and treat their waste prior to disposal.• A regular qualitative and quantitative monitoring of fresh water resources • Construct proper sanitary landfill sites• Investigate ground water quality• Provide Government help for waste management by industries• Throw refuse into garbage cans. Visitors who throw garbage into pools, lakes, ponds, and even along the beaches pollute recreational sites on a daily basis. This not only pollutes the water but also mars the beauty of the site• Dispose of unwanted paints or oils carefully. They should not be thrown into drains or sewers• Participate in awareness raising activities. Students can be a great help in this regard• Conserve water at home and at work, rather than wasting it• Boil or filter drinking water to eliminate disease-causing bacteria• Conducting epidemiological study in the areas close to contaminated water bodies will help to assess the affect of polluted water on health of the consumers. WWF's Position
WWF has focused its attention on the issues of urban and industrial pollution. It provides assistance to the industrial sector in reducing polluted discharges into air, water and soil.WWF-Pakistan enhances capacity of industrial sector so that they can implement environmental solutions. In this regard, training workshops have been organised on the subjects of industrial waste management and waste minimisation technology. To promote environmental awareness of water pollution issues, a water pollution monitoring kit (mobile laboratory) was developed by WWF and launched in the four provinces of Pakistan. The kit is easy to use and is fabricated using cost effective material. It is capable of monitoring 14 pollutants.For more information on Water Pollution, please visit the following sites:www.iwpca.orgwww.ec.gc.cawww.soton.ac.ukwww.life.cawww.eihs.niehs.nih.govwww.ssr.comwww.webdirectory.com/pollution/water_pollutionwww.cities.poly.eduwww.bpinews.comwww.state.nv.us Compiled and edited by Environmental Pollution Unit, WWF- Pakistan