KARACHI, April 24: Out of over 400MGDs of raw sewage generated by the city, 315 million gallons daily (MGDs) is released into the Arabian Sea without treatment, polluting marine environment and causing considerable damage to naval installations.

The remaining 85MGDs of raw sewage is partially treated, without removing deadly industrial waste before being released into the sea.

The financial loss sustained by the Pakistan Navy on account of marine pollution is around Rs60 billion a year — a fact disclosed by former defence secretary Tariq Waseem Ghazi and Commander Pakistan Navy Rear Admiral Mehmood Ahmad Khan at a recent meeting of the Senate Standing Committee on Defence.

The Karachi Water and Sewerage Board is entrusted with the task of treating the city’s domestic and municipal sewage before releasing it into the sea. But, sources said, the three treatment plants run by the KWSB remained under-utilised. They added that even if the fourth KWSB treatment plant — currently at the planning stage – became operational, the department would not be able to treat the city’s 400MGDs raw sewage.

The sources said that while the bulk of the city’s sewage was generated by households, more dangerous industrial effluents found their way into the municipal sewerage system, various storm-water drains and the Malir and Lyari rivers meandering through the city.

Karachi is home to one of the largest industrial centres in the country containing garment factories, textile mills, tanneries, pharmaceutical companies, chemical plants, refineries, petrochemical units and pesticide formulators – all generating hazardous industrial effluents.

The sources said most industrial units did not have in-house secondary treatment facilities. A top official of the Sindh Environmental Protection Agency, who requested not to be named, said that under relevant laws all the industrial units were legally bound to install in-house treatment plants, treat their effluents and bring them within the NEQS (National Environment Quality Standards) levels before their release. He conceded that most industrial units did not have such facilities.

He said Sepa was short-staffed, adding that even existing staff were not technically trained to keep a check on industrial units.

The sources said that while the total installed treatment capacity of the three KWSB treatment plants was 156MGDs, they were treating just around 85 MGDs. The treatment plants are located in SITE, Mahmoodabad and Mauripur.

“While the KWSB planners increased the treatment capacity of the two plants — known as TP-I and TP-II in official parlance — they did not ensure that the required amount of sewage found its way to the treatment plants. As a result, the plants remain only 60 per cent utilised,” the sources explained.

The water and training chief engineer of the KWSB, Asudomal, said another 100 MGD treatment plant was being planned at the Korangi creek. He said efforts were being made to fully utilize all the three treatment plants so that the bulk of sewage being generated by the city could be treated before being released into the sea. He added that measures were being taken to bring more sewage to the treatment plants.

The sources said porous KWSB pipelines also caused the contamination of drinking water. They said most water and sewage pipelines, laid close to one another a long time back, had fallen into disrepair. Seismic activity in the region – not felt by humans — also caused underground pipelines to develop leaks.

“Quite often the water pipes remain empty and develop negative pressure that enables them to suck in sewage flowing in a neighbouring leaking pipeline. And when the water supply is resumed, the sewage-infested water finds its way to households,” they said.

Pakistan Medical Association Secretary Dr Qaiser Sajjad said contamination of drinking water was a serious problem that affected millions of people. He added that over 1.2 million people, including over 250,000 children below the age of five, died of water-borne diseases in the country every year.