HYDERABAD, Feb 26: The industrial effluent being released into Kalri Baghar Feeder, which flows into Keenjhar Lake, - sources of drinking water for Jamshoro, Kotri, Thatta and Karachi – contains heavy metals posing a serious threat to human health, aquatic life and plantation, according to environmental experts.

“Around four varieties of heavy metals are found in the samples of water that goes into KB feeder from oxidation pond created by industrialists in Kotri,” Water Technologist Prof. Dr. Ahsan Siddiqui told Dawn on Tuesday.

He feared the lake would become another Manchhar over the next five to 10 years if the toxic levels in the feeder’s water were not brought down to render the water harmless for human life.

He said he had obtained the samples in the presence of Director General of Sindh Environmental Protection Agency (SEPA) Abdul Malik Ghauri in the first week of February.

The results showed the effluent contained magnesium, iron, lead and chromium at 400 mg per litre, 62mg/1, 1.1mg/l and 4.4mg/l, respectively, he said. As per National Environmental Quality Standards (NEQS) the limit of iron in water had been set at 8mg/l, lead at 0.5 mg/l and chromium at 1mg/l and no limit had been set for magnesium, he said.

He believed that magnesium should be less than 200 mg/l. The samples were taken after water was released from facultative ponds (oxidation ponds) directly into KB feeder.

The industrialists of Kotri had built the ponds to retain water for some period before releasing it into the feeder, under the belief that it would help overcome hazardous affects in the effluent. But, the water expert did not approve of them. DG SEPA Abdul Malik Ghauri agreed with the expert that the oxidation ponds were merely serving for sedimentation.

“Wastewater is not retained in the pond for 10 to 40 days to neutralise oxidising agent metals. It should be made binding on each industrial unit to release wastewater after meeting NEQS,” he said.

DG EPA confirmed that he had received report on water samples from the water technologist. The managements of Site and KATI had been asked to bear the cost of treatment plant and he would set a cut-off date for the plants’ establishment, he said.

Kotri-based industries are discharging untreated effluent into the ponds despite strong recommendations by EPA and environmental experts that they should set up treatment plants within their premises.

Mr Siddiqui said that the ponds were designed without keeping in mind scientific standards and ascertaining the pond’s depth. Chromium could cause kidney ailments while lead could lead to brain damage and magnesium could cause gastro diseases, he said.

He said that the quantity of heavy metals in the effluent could be brought down through reactors. “We have designed such a reactor in Mehran University of Engineering and Technology (MUET), which has recovered chromium,” he said.

The heavy metals would first destroy the land of lake and do away with its aquatic life and plantation. If the lake’s water was used for irrigating land it would make it barren, he said, giving the example of Manchhar Lake where the land surrounding the lake had turned barren.