ISLAMABAD, Feb 23: A severe form of water pollution caused by disposal of waste water into the Ravi and Chenab rivers has put lives of over 2.6 million people of Faisalabad, the third largest city of Pakistan and an industrial hub, in extreme danger.

The Pakistan Council for Research in Water Resources (PCRWR), Islamabad, a research organisation of the Ministry of Science and Technology, recently conducted a study on the impact of waste water on surface and ground water and human health in Faisalabad.

The council has come up with some mind-boggling findings that also include the revelation that some 30 to 40 per cent patients in the city are suffering from waterborne diseases and that vegetables and drinking water are polluted with iron and are not safe for human consumption.

A detailed analysis of drinking water contamination found 39 per cent samples of public water, 57 per cent of ground water, 60 per cent of groundwater near drains and 58 per cent of ground water near canals microbiologically unfit and hence not safe for human consumption.

The chemical quality of waste water used for irrigation purposes was found entirely unfit.

The water provided by the Water Supply and Sanitation Agency (Wasa) was found fit for irrigation but it is was being disposed of into Patharang drain without any productive use. The samples of the soil irrigated with waste water were found with excessive quantitative of nickel (Ni) and cadmium (Cd).

Although these elements were found within the permissible limits in waste water, the continuous use of waste water for irrigation might have increased these elements in the soil, the council observed.

Similarly, the vegetables grown with waste water were found contaminated with chromium (Cr), lead (Pb), cadmium (Cd) and iron (Fe). The vegetables irrigated with industrial waste water showed higher contents of heavy metals. Wheat, sorghum, lettuce, mint and turnips were found to have more contaminant uptake capability, whereas sugarcane and barley showed least contaminant uptake capability.

The analysis of fish reared with poor quality groundwater indicated nickel and lead up to the toxic level. Therefore, the council has advised that rearing of fish in the peri-urban areas with poor quality groundwater be avoided.

"The irrigation with untreated waste water should be stopped immediately," the council has warned.

Low-cost water treatment facilities are needed for industrial units and the strict implementation of environmental policy must be ensured. Groundwater quality of the city is very poor and necessary efforts should be made to extend regular supplies of Wasa water for the entire community with regular monitoring of its quality, the council suggests.

According to PCRWR, water of the city was being disposed of in the Ravi and Chenab rivers through Madhuana and Parhang drains and about 7.29 cubic meter per second waste water was finally being discharged into the rivers. Waste water analysis showed that 83 to 100 per cent samples exceeded the permissible limits with respect to Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD).

The BOD is a test used to measure the concentration of biodegradable organic matter present in a sample of water, while COD test is commonly used to indirectly measure the amount of organic compounds in water samples.